Final study set Flashcards
1
Q
Adenine bonds to…
A
Thymine
2
Q
DNA v RNA
A
DNA: double helix, phosphate, 5-carbon sugar, nitrogenous base, AT, GC
RNA: Single strand, AU, GC
3
Q
Darwin v Lamarck
A
Lamarck: permanent spontaneous generation, adaption to environment, complexification over time, only human caused extinctions
Darwin: derived from an ancestral form, natural selection, spontaneous variations transmitted from phylogeny, yes extinctions
4
Q
How did Darwin and Wallace come up with their theory?
A
Darwin: Galapagos — told that they could identify which island turtles are from their shell. Mockingbirds were key — they were different on each island. Finches confirmed it.
Wallace’s specimen in Southeast Asia - tends to the idea of evolution and writes letters to Darwin and collaborated on the scientific papers. 125,000 specimens drew a boundary line through Southeast Asia that divides Asian and Australian animal groups
5
Q
Darwin v Wallace
A
Differences:
- Darwin believed in Lamarck - didn’t understand alleles
- Wallace talked about more favorable traits being passed down (anti-Lamarck)
- Wallace addressed the anti-evolutionary arguments
- Darwin talks about geological time (Charles Lyell)
- Darwin talks about sexual selection (not just predation - not the most survivable traits like bright colors)
Similar
- struggles for existence
- domestication (justifies in different ways)
- Darwin: if humans can do it, so can nature
- Wallace: they go against natural selection because they wouldn’t survive in nature - dogs only exist that way because humans removed the external environment.
- exponential growth argument
- natural selection as a principle
6
Q
Describe how their theories were different from existing theories
A
- Past theories said that the earth was young (4004 bc)
- special creation- god created species (topological thinking)
- revolutionary:
- population thinking: Variation was normal, not an error, and necessary for the survival of the species.
- species not static + common ancestry
-it was scientific — added process components that’s predictive and testable
7
Q
Why does the earth have to be old?
A
Earth is about 4.5-4.6 billion years old, so plenty of time to evolve
8
Q
List key elements of darwins theories
A
species change and frequencies of traits change over time which allows for diversification that all comes from a common ancestor. Random changes result in an increase in fitness which allows them to produce more offspring which changes the frequencies of traits in population.
9
Q
Describe the 8 lines of evidence
A
(1) vestigial traits - useless/unnecessary traits (whale hip bone)
(2) Inefficiencies + imperfections (human v squid eyes)
(3) Homology - similar structures between animals (human arms, bat wings, horse legs)
(4) Transitional fossils - process from an individual (tiktaalik)
(5) hierarchy of life - in monophyletic groups from common ancestor (beetles and butterflies and humans and cats are all animals)
(6) Artificial breeding - (dogs or pigeons)
(7) intermediate forms - simple to complex - (eyes)
(8) biogeography- animals fossils in spots that they lived due to the law of succession
10
Q
How to write the name of a species?
A
Genus then species italicized (the whole thing)
11
Q
How do you make a phylogenetic tree?
A
Use homologous traits
12
Q
Define homoplasy
A
Homoplasy is convergent evolution. Homology is evolving from the same ancestor and having the same features.
13
Q
Define synapomorphy
A
- A trait that defines a group of organism
- A trait that is a common property shown by 2 or more groups of organisms that can be traced back to the most recent ancestor that both the groups evolved from.
- However, this character may not be shown by other closely related groups
14
Q
Explain the synapomorphies that define the three domains of life: bacteria, archaea, eukarya
A
Bacteria: no nucleus, peptidoglycan, unique rRNA, unbranched fatty acid chains, circular DNA
Archaea: no nucleus, no peptidoglycan, unique rRNA, branched hydrocarbon chains, circular DNA
Eukarya: nucleus, no peptidoglycan, unique rRNA, unbranched fatty acid membranes, linear chromosomes
15
Q
Create a relative timeline for the evolution of life on earth
A
- Earth : 4600/4500 MYA (4.6/4.5 BYA)
- Oceans
- First life : 3800 MYA (3.8 BYA)
- Rise of O2 : 2400 MYA (2.4 BYA)
- Eukaryotes: 1800 MYA (1.8 BYA)
- Cambrian explosion : 540 MYA
- Permo X! : 252 MYA
- Dino’s : 245 MYA
- Atlantic Ocean
- Dino x!/ rise of mammals : 65 MYA
- Himalayas
- Rise of humans
- Wooly mammoth x!
16
Q
Explain the causes of diversification during the Cambrian explosion
A
- Rise of O2 - aerobic respiration means more complex movements, rise of algae caused this
- New niches beget new niches - if something can live in a new niche, something else can live on it or eat it
- Predation - forces species to evolve to increase survival chance
- New genes - Hox genes increased embryonic complexity
- Devonian expansion - expansion of land plants
17
Q
Describe Darwin’s 4 postulates
A
(1) Traits are variable - random, can be different between individual organisms (mutations)
(2) struggle for survival - creatures have to survive with predation and are fit enough to mate
(3) Traits are heritable - the variable traits can be passed down from generation to generation
(4) Individuals with favorable traits survive and reproduce which increases the frequency of the trait over time
18
Q
Explain how anti-biotic resistant bacteria show evidence for Darwin’s 4 posulates
A
- Variability: There is a variability in how resilient bacteria is to antibiotics (mutations increase and decrease it)
- Heritability: the gene can be passed down (proven by graph evidence across generations
- Struggle for existence: the antibacterial will kill the vast majority
- Fitness: the changed heritable gene allowed the bacteria with it to survive the antibiotic and reproduce
19
Q
What are some tips and tricks on how to identify Darwin’s 4 postulates based on the graph given?
A
- variation: just shows that there is differences
- heritability: mid-offspring v mid-parent graphs
- struggle for existence: identifies a factor (ex: before and after hurricane, or before and after drought)
- differential survival and reproduction - shows that there is a shift in the distribution of the graph
20
Q
Describe adaptations and fitness
A
Adaptations: a trait in an individual that is heritable and increases fitness
Fitness: overall ability for an individual to survive and reproduce fertile offspring
21
Q
What are common misconceptions on nature selection and why are they dumb?
A
(1) Individuals changing - no populations change
(2) evolution has a goal - no it is random and selection is based on the environment
(3) evolution = perfect - nom just good enough (ex human eye)
(4) directed mutation - no it is random not because an organism wishes it
(5) all mutations are bad - some are beneficial (I.e which fur on beach mice), some are deleterious
(6) evolution is always toward greater complexity - not always - tapeworms lost their digestive tract
22
Q
Explain some experiments to test the adaptive value of a trait
A
(1) pre and post hurricane analysis of species features - like the lizards
(2) beach and field mice experiment - put fake mice in the environment to test which are eaten
23
Q
What are the core differences between adaptations and natural selection? Also what is adaptive radiation?
A
Natural selection: a shift in the frequency of traits of a population over time due to the environment/predation. The variation in traits is caused by mutations
Adaptation: an individual better acts to survive in its environment, increasing fitness
Adaptive radiation: when 1 lineage produces many other descendent lineages with a wide range of adaptive forms (fast, many niches, they’re a monophyletic group)
24
Q
Which is archaeopteryx most closely related to? Enantiomithes, Aurornis, Dromaeosauridae
A
Enantiomithes
25
Which statement is true?
(A) Archaeopteryx is a transitional fossil, providing evidence for the gradual evolution from dinosaurs to birds.
(B) Archaeopteryx is the ancestor of “true birds”.
A
26
Do archaea and bacteria (prokaryotes) form a monophyletic group?
No
27
Which is not a theory of Darwin?
(A) Change occurs in jumps.
(B) All life descends from a common ancestor.
(C) Life became more diverse over time.
(D) Species change.
A
28
Ichthyosaurs, now extinct, were aquatic reptiles with dorsal fins and tails, similar to those of fish. Their most recent ancestors were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are :
(A) adaptations to a common environment and examples of convergent evolution (homoplasy)
(B) adaptations to different environments
(C) homologous structures
A
29
The average height of humans has increased. Most of this is hypothesized to be because of better nutrition and less disease. Has human height evolved?
Yes; height is a heritable trait.
Variation: height genes
Heritable: yes
Struggle: Better nutrition
So produce more offspring which increases frequency of genes
30
How can evolutionary fitness be estimated?
Count the number of healthy, fertile offspring produced
31
Which postulate is not represented? If any?
Traits are heritable
32
In lizard ppopulations, what ar ethe primary changes that occur over time?
(A) The traits of each individual lizard within a population gradually change.
(B) The proportions of lizards having different traits within a population change.
(C) Successful behaviors learned by certain lizards are passed on to offspring.
(D) Mutations occur to meet the needs of the lizards as the environment changes.
B
33
Describe the inheritance patterns of a single trait
Dominant + Heterozygous = Dominant
Recessive requires both alleles to be recessive
34
Describe dominance and recessiveness
Dominant: the trait will presentas the trait over a recessive allele. Only requires 1 allele for the phenotype to present as the dominant allele.
35
What is the law of segregation?
The alleles are segregated when they go through meiosis -- the alleles are not passed together. Each gamete has an equal probability of containing either allele.
36
If you have a dominant and a recessive mate what is the phenotypic ratio and genotypic ratios?
100% Heterozygous. All will have the dominant phenotype.
37
If you have tall parents that have a 3 tall:1 short ratio of offspring; is tall dominant or recessive
dominant
38
1 yellow : 1 green phenotypic ratio in the offspring, where yellow is dominant, means that the parents were____?
1 parent: hetero, 1 parent: homo rec
39
Expain the law of independent assortment
Law of independent assortment: the crossing of 2 pairs of traits -- each trait is independent (key in dihybrid crosses. Yellow and hairy are independent)
40
How to tell if it is autosomal dominant
- Never skips a generation
- Equal probability for men and women
41
How to tell if it is Autosomal recessive
- Skips a generation
- Equal prob for women and men
42
How to tell if it is X-linked dominant
- Men will give it to ALL DAUGHTERS
- Men can never give to a son
- Mothers if heterzygous could give it to any of them
- AA mother will give it to ALL OFFSPRING
43
How to tell if it is X-linked recessive
- Men will never give t sn
- Mothers will give half to son, but dominant fathers mean that no daughters will have it
- If Mom is heterozygous and dad has it -- half daughters and half of the sons will have it
44
A boy is terminally ill with a rare genetic disorder called adrenoleukodystrophy (ALD). ALD is caused by a mutation that leads to progressive brain damage, failure of the adrenal glands, and eventual death. A pedigree of a family with ALD follows.
ALD is caused by mutations in one gene. Given the symptoms of ALD, which of the following terms describes the disease- associated allele?
A. pleiotropic
B. Recessive
C. dominant
D. polygenic
B -- skips generations
45
A boy is terminally ill with a rare genetic disorder called adrenoleukodystrophy (ALD). ALD is caused by a mutation that leads to progressive brain damage, failure of the adrenal glands, and eventual death. A pedigree of a family with ALD follows.
Given the pedigree, what is the most likely mode of transmission of ALD?
A. autosomal recessive
B. X-linked recessive
C. autosomal dominant
D. X-linked dominant
B -- it is found only in males
46
A boy is terminally ill with a rare genetic disorder called adrenoleukodystrophy (ALD). ALD is caused by a mutation that leads to progressive brain damage, failure of the adrenal glands, and eventual death. A pedigree of a family with ALD follows.
Which phrase describes the female in the first generation?
A. likely to be homozygous for the recessive allele
B. likely to be homozygous for the dominant allele
C. likely to be heterozygous
D. equally likely to be homozygous dominant or heterozygous
C -- without the recessive gene, there would be no recessive allele for other generations to inherit
47
This is an autosomal rec trait. What is the genotype of II 1?
Aa
48
What is the probability that II 3 and 4 will have a child with the disease?
50 percent
49
Why is the pea wrinkled-seed allele a recessive allele?
a. It “recedes” in the F2 generation when homozygous parents are crossed.
b. The trait associated with the allele is not exhibited in heterozygotes.
c. Individuals with the allele have lower fitness than that of individuals with the dominant allele.
d. The allele is less common than the dominant allele. (The wrinkle allele is a rare mutant.)
B
50
Both parents are heterozygous for both height and color traits. (T= tall , t = short , B = black, b = white) After a dihybrid cross, what can you predict the phenotypic ratios of their offspring to be?
9:3:3:1
51
If the ratio must be 1:1:1:1 with 2 traits, R and V, what is the parental genotype?
RrVv x rrvv
52
In humans, a gene controls whether cheeks have dimples. The occurrence of dimples is dominant over having no dimples. The possession of freckles is also genetically controlled. People with freckles have the dominant trait, while those without freckles have the recessive trait.
Suppose a woman with dimples and freckles marries a man who has no freckles and no dimples. Let D represent dimples, d represent lack of dimples, F represent freckles and f represent lack of freckles.
Based on the information provided so far, what possible genotypes could the woman be?
DDFF, DdFF, DdFf, DDFf
53
In humans, a gene controls whether cheeks have dimples. The occurrence of dimples is dominant over having no dimples. The possession of freckles is also genetically controlled. People with freckles have the dominant trait, while those without freckles have the recessive trait.
Suppose a woman with dimples and freckles marries a man who has no freckles and no dimples. Let D represent dimples, d represent lack of dimples, F represent freckles and f represent lack of freckles.
Following up from question 1: the woman and man have a lovely marriage and end up having 17 children. Of these, 4 have no freckles and no dimples. Based on this new information, once again choose all possible genotypes that the woman could be.
DdFf
54
Suppose Mendel crossed a heterozygous pea plant with tall height and round seeds with a plant of unknown genotype and phenotype. In peas, tall height (T) is dominant over short height (t) and round seed shape (R) is dominant over wrinkled seed shape (r).
Suppose that this cross results in the following offspring: 89 tall plants with round seeds, 86 tall plants with wrinkled seeds, 31 short plants with round seeds and 28 short plants with wrinkled seeds. What is the genotype of the unknown plant?
Ttrr
55
The following pedigree chart shows the inheritance of sickle cell disease, which is based on an autosomal recessive trait. Diseased individuals are indicated by a filled square or circle, while carriers are shown with a half-filled square or circle. Females are indicated with circles, and males with squares. Two individuals (1 and 2) are of unknown genotype (their lack of shading does not convey information). If A denotes the dominant allele and a denotes the recessive allele, what genotype must the male indicated with “1” be? And what is the probability that the female indicated with “2” will be a carrier (lack of shading for individual 2 does not convey information)?
Aa; 100 percent
56
Describe the chemical characteristics of water and their role in supporting life
(1) High surface tension
(2) Ice is less dense than water : this is key because otherwise oceans would freeze on the bottom, instead of acting as an insulator for ocean life in the winter
(3) High capacity for absorbing energy (specific heat and heat of vaprization)
(4) Role of wtaer in acid-base rxns : water is key to making ion soup and causing them to run into each other
57
Classify molecules as more hydrophobic or hydrophillic
If they are polar -- hydrophillic, if they are nonpolar -- hydrophobic
58
Explain the role of valence electrons in forming chemical bonds, in particular, ionic and covalent bonds.
Valence electrons will be partially or fully lost or gained to increase stability (lower potential energy of the compound)
59
Distinguish between hydrogen bonds, ionic bonds, and polar/non-polar covalent bonds resulting from differences in atomic electronegativity (O>>N>C≈H).
H bonds: H in a polar covalent bond to elements with Hs in polar covalent
Covalent: sharing
Van der waals: nonpolar interactions
Ionic: takes electrons and forms crystal lattices with their strong attractive forces
60
What does amphipathic mean?
Has a polar and a nonpolar end
61
Discuss the importance of pH and buffers to living systems
pH is carefully regulated because of the need for a stable place for reactions to occur (blood is slightly acidic) – need to have carbonic acid buffer to carefully maintain homeostasis
62
Use 2 distinct experiments as evidence for DNA as the genetic material of life (image of hershey chase experiments)
(1) Hershey chase experiments: they added sulfur labeled capsuls and then phosporus labeled DNA, and saw whether the pellet was radioactive (cells) -- capsule was made of proteins and was in the supernatent, DNA made of nucleotides was in the pellet
(2) Mouse death experiments: they added protease, dnase and rnase to see which was the genetic material in the 4th experiment, because the DNase made it so the S strain could not grow in the transformed bacteria and the mice survived
63
Explain what evidence led to the discovery of DNA structure.
Photo 51, chemistry base pairing understandings
64
What is the difference between ribo and deoxy nucleotides?
A. Deozxyribose has one less oxygen on the 2nd carbon
B. Deoxy has T, Ribose has U
65
What bases are purines?
Adenine and Guanine they bond 3 times
66
What bases are pyrimadines?
Cytosine, Thymine, and Uracil
67
What are the 3 parts of a nitrogenous sugar?
Deoxyribose (sugar), phosphate group, nitrogenous base
68
What is the 3 end and what is the 5 end?
3rd carbon v 5th carbon
69
what is Chargaffs rule?
A's = T's or U's, G's=C's (EX: 20 percent T means 20 percent A's, and 30 percent of C and 30 percent of G)
70
Scientists carried out experiments with Streptococcus pneumoniae. The smooth strain of this bacterium is virulent and kills mice, whereas the rough strain does not. Based on the following experiment, what could scientists conclude regarding genetic material?
- The genetic material is DNA
- Genetic material can be passed from smooth to rough bacteria.
71
Compare and cntrast eukaryotic and prokaryotic genomes
The prokaryotic genomes are mostly single circular chromosomes. Eukaryotic genomes consist of one or two sets of linear chromosomes confined to the nucleus.
72
Use DNA and RNA structures to explain the difference in DNA and RNA functions within cells
- DNA is a double helix
- RNA is a single strang -- creates a loop and binds to itself somewhat
73
Identify chemical properties of amino acids
Have amine group, an H group, carboxyl group, and R side chain
74
Identify locations of peptide bonds and R groups (side chains) in peptide chains
The R side chain is between the carboxyl and amine group
75
Describe the primary, secondary, tertiary, quaternary structures of proteins and the types of bonds that stabilize each
- Primary: list of amino acids bonded together by peptide bonds that form from condensation reactions
- Secondary: only H bonds formed from side chains
- Tertiary: H bonds, disulfide bridges, van der waals interactions (hydrophobic interactions), ionic bonds
- Quaternary: hydrophobic and hydrophilic interactions between parts of amino acids
76
Predict how mutations in amino acids might affect the three-dimensional structure of a protein
May change the R-side chain which determines the ability for them to be able to form hydrogen bonding, whether they’re polar, nonpolar or charged which impacts their ability to interact with other side chains
77
Draw the structure of an amino acid and a dipeptide.
It occurs between the carboxyl group and the amine group through dehydration synthesis.
78
Describe how DNA can encode the primary sequence of an amino acid via an RNA intermediate
DNA template → DNA coding → mRNA → AA’s
79
Trascribe DNA to mRNA
- Coding strand to mRNA strand is just change T’s to U’s
- Be able to read 5-3
- Template strand (read 3-5)→ mRNA (5-3) where you write the sequence — if template is 5-3 then translate and flip
80
translate a messenger RNA into a peptide sequence
Divide into codons
81
Describe different classes of DNA mutations and predict severity of these mutations on protein structure/function: silent, missense, nonsense, frameshift.
- Silent: no effect on amino acid
- Nonsense: stop codon
- Frameshift – ad or subtract
- Missense – change animo acid
82
T bonds to A, how many times
2
83
G bonds to C, how many times
3
84
Convert this DNA sequence: ACT CCT GAG GAG AAG to
Thr-Pro-Glu-Glu-Lys
85
Convert this DNA sequence: ACT CCT GTG GAG AAG
Thr-Pro-Val-Glu-Lys
86
Thr-Pro-Glu-Glu-Lys --> Thr-Pro-Val-Glu-Lys. what type of mutation is this?
missense mutation
87
What interactions occur in the secondary structure?
Alpha helix or beta pleated sheets -- H bonds form on the backbone
88
What interactions occur in the tertiary structure?
R group interactions that contribute to tertiary structure include hydrogen bonding, ionic bonding, dipole-dipole interactions, and London dispersion forces
89
Describe Cell Theory
- All living organisms are made up of cells
- Cell is the basic unit of life
- Cells arise from preexisting cells
90
Describe key differences between prokaryotes, eukaryotes and viruses
- Prokaryotes
a. DNA is naked
b. DNA is circular
c. No nucleus
d. No membrane-bounds
e. Binary fission
f. Single chromosome (haploid)
g. Smaller
h. Unique ribosomes
- Eukaryotes
a. DNA bound to protein
b. DNA is linear
c. Has a nucleus
d. Membrane-bound
e. Mitosis and meiosis
f. Unique ribosomes
g. Chromosomes paired (diploid or more)
h. Larger
- Viruses
a. No organelles
b. Host replication
c. No metabolism machinery
d. Capsid
91
List the 3 main types of lipids and their common functions
Steroids
- has carbon rings that are hydrophobic with an O=H
- EX: cholesterol
Fatty acids
- three fatty acids linked to a glyercol
Phsopholipids
- membrane
- ampiphathic
92
Label the organelles/cell structures indicated with letters A-J.
A) cell wall
B) chloroplast
C) vacuole
D) nuclear envelope
E) nucleolus
F) rough endoplasmic reticulum
G) smooth endoplasmic reticulum
H) Golgi apparatus
I) mitochondrion
J) cell membrane
93
Choose the molecule that would most easily pass through a phospholipid membrane (assume no pores/channels/pumps).
B
94
Explain the selective permeability of membranes and factors that adjust permeability
- Glucose can move more through with less cholesterol
- Small, nonpolar move through easily
- Some small polar can move through
- Some large nonpolar can go through
- IONS CANNOT GO THROUGH
95
Explain the four factors (length of fatty acid tail, saturation of fatty acid tail, temperature, cholesterol) that influence the permeability behavior of a cell membrane.
- Saturation: more saturated, more bonding, decreased permeability
- Longer: longer, more bonding, decreased permeability
- Temperature: decreased temperature, slower molecules, decreased speed of permeability
- Cholesterol: increased bonding and strength which decreases permeability
96
Describe endosymbiont hypothesis
The endosymbiotic theory states that mitochondria and chlopoplasts in today's eukaryotic cells were once separate prokaryotic microbes.
97
Copepods are small planktonic animals. The graph (Hassett and Crockett 2008, J. Exp. Biol. 212, 71) shows the cholesterol content of the cell membranes of two copepod species living at different ocean depths and experiencing different temperatures. In the space provided, explain which of the two species (2 or 9) most likely lives in shallower and warmer water.
A. Species 2 more likely lives in shallower and warmer water than species 9
B. Species 9 more likely lives in shallower and warmer water than species 2
C. Both species are equally likely to live in shallower warmer water
B
98
Which of the following would be true when there is a concentration gradient across a membrane for molecule X that CANNOT pass through the membrane (but water can)? Choose all true statements.
A. Some water molecules would move from the lower X concentration side to the higher X concentration side
B. Some water molecules would move from the higher X concentration side to the lower X concentration side
C. The net movement of water would be from the lower X concentration side to the higher X concentration side
D. The net movement of water would be from the higher X concentration side to the lower X concentration side
A, B, C
99
One of the main public health recommendations to protect against Covid-19 is to wash your hands regularly with soap. This is because soap is effective at breaking a particular structure of the SARS-CoV-2 virus. Which structure is this?
the envelope
100
The picture shows the life cycle of HIV virus, which is a retrovirus. Label A, B and C with the correct words.
A: RNA
B: reverse transcriptase
C: transcription
101
Describe the endomembrane system
Free ribosome, RER, Golgi, Vesicles
102
Describe the structure and replication cycle of different types of viruses
- Some viruses have RNA v DNA
- Some enveloped some not enveloped
- Enveloped tend to not burst the cell (lysis)
- Non enveloped do lysis
- Have their Capsid – made up of proteins
- Envelope made up of Lipids
103
Explain whether viruses are alive based on cell theory
NOT ALIVE – CANNOT REPLICATE
104
Lysis cycle vs lysogenic
105
How many double helices are shown in the picture?
8
106
The following cell is in G1 phase and has two sets of chromosomes, one from the mother (indicated with alleles A and B) and one from the father (indicated with alleles a and b). Students were asked to draw the phases of mitosis that this cell would go through. Below are four pictures. Three are incorrect, and one is correct. Choose the correct drawing.
3
107
The following figure shows 5 microscopic photos of Allium root tip cells, in which the chromosomes are stained red. Match the picture with the most likely cell cycle phase or stage of mitosis. Note: you should use choose each option only once.
A. Anaphase
B. G2 phase
C. prometaphase
D. Metaphase
E. Telophase
108
Meselson and Stahl grew bacteria in the presence of radiolabeled nitrogen (15N) such that their genome was labeled with 15N (generation 0). They then continued to grow the bacteria in the absence of 15N (only non-radioactive 14N was present), and ran the bacterial genome out in a gradient tube after each generation. Imagine they had obtained the following results. Which models of replication are the results for scenario A and B consistent with?
A: semiconservative
B: dispersive
109
Describe the function of the cytoskeleton in terms of transport, motor proteins, cell structure, spindle formation
- Microtubules are also key components of three more specialized eukaryotic cell structures: flagella, cilia and centrosomes. motor proteins called dyneins move along the microtubules, generating a force.
- Actin filaments may also serve as highways inside the cell for the transport of cargoes, including protein-containing vesicles and even organelles
- Intermediate filaments play an essentially structural role in the cell
110
Recognize and label phases of mitosis based on microscopic images
- Prophase – Nuclear envelope begins to disintegrate and DNA is in squiggles but its identifiable – spindle fibers form
- Prometaphase – spindle fibers begin to connect and it looks more like DNA
- Metaphase – lined up in the center
- Anaphase – started to being pulled towards centrioles (which make up the centrosome) from the centromere (made up of by the kinetochores)
- Telophase – nuclear envelopes begin to reform and to split
111
Explain the differences in cytokinesis in animal and plant cells
Animal cells: cleavage furrow
Plant cells: expand and build a new cell wall
112
Describe the phases of the cell cycle (G1, S, G2 and M) and broadly explain what cellular processes happen during each phase
G1 – growth
S – replication of DNA
G2 – growth and replication of organelles
M – where they divide
113
Describe role of DNA condensation during cell cycle
Key to making the DNA easily seperatable
114
Explain the Meselson-Stahl experiment, and predict the experimental outcomes of this experiment based on the models of conservative, semi-conservative and dispersive DNA replication
Shows semi-conservative : an old strand codes for a new strand and they create the new double helix.
115
Define ploidy
the number of sets of chromosomes in a cell, or in the cells of an organism.
116
Explain how pulse-chase experiments can be used to study the cell cycle
Pulse-chase analysis is a commonly used technique for studying the synthesis, processing and transport of proteins. Cultured cells expressing proteins of interest are allowed to take up radioactively labeled amino acids for a brief interval (“pulse”), during which all newly synthesized proteins incorporate the label.
117
Explain the difference between asexual and sexual reproduction
Asexual is only women
Sexual is men and women
118
What are the Evolutionary costs of sexual reproduction
- Two-fold cost of sex (sexual females produce half the number of grand-offspring as asexual females)
- The fact that females can only pass on 50% of their genes
119
Describe some benefits of sexual reproduction
- Genetic variation
- Evolve more readily in new environments
120
Explain John Maynard Smith’s null model for the evolution of sex
Explains the 2 fold cost of sex -- lots less offspring created through sexual reproduction
121
Describe the phases of meiosis
Prophase 1: Chromosomes duplicated and crossing over happens
Metaphase 1: seperates homologs
Anaphase 1: further seperates homologs
Telophase 1: seperates into haploid cells with duplicated chromosomes
Prophase 2: new spindles form -- NO NEW CHROMOSOMAL DUPLICATION
Metaphase 2: sister chromatids line up at the equator
Anaphase 2: sister chromatids are seperated
Telophase 2: 2 --> 4 daughter cells all haploid
122
Explain how meiosis results in segregation, independent assortment, and crossing over
A. Segregation: the traits were not connected to one another
B. Independent assortment: a and B can be put next to each other
C. Crossing over: happens in prophase
123
Explain how crossing over can contribute to generating genetic variation.
Even more variation in which genes are randomly assorted and also include other genes
124
Explain the consequences of meiosis gone wrong
Down syndrome
125
The different copies of chromosome 21 for a couple and their child are shown to the right. A1-A4 are different alleles of the same gene.
When and where did the mistake occur?
Meiosis I of parent #1
126
Which of the following student models would be the most useful for illustrating the principle of independent assortment?
B
127
Place the pictures of meiotic stages in the right order.
B -> E -> D -> A -> C
128
Below follow six drawings of metaphase I for the following cell. None of the drawings are perfect (or beautiful). Which one is the BEST visualization of metaphase I of this cell?
A
129
The tree shows the evolutionary relationships between Denisovans, Neanderthals, and Homo sapiens in Africa and Asia/Europe, based on mitochondrial DNA sequences. According to this tree (circle all that apply):
A. Neanderthals are more related to Africans than they are to Denisovans.
B. Modern humans evolved in Africa, then migrated to Asia and Europe.
C. Denisovans are equally related to Africans and Asians and Europeans.
D. Europeans exchanged more genes with Neanderthals than did Africans.
A, B, C
130
Choose all correct statements regarding the evolution of human skin color.
A. The evolution of light skin in northern Europe occurred because of relaxed selection: because of less UV radiation (compared to equatorial Africa), light skin did no longer result in a break down of folate.
B. The evolution of light skin of people in northern Europe occurred because of positive selection: lighter skin allows more UV to penetrate the skin, and this is essential for vitamin D production.
C. The evolution of dark skin in equatorial Africa occurred because of negative selection: mutations that change the amino acid sequence of MC1R would result in lower folate levels and therefore lower fitness.
A, B, C
131
The graph shows the number of alleles of the MC1R gene of a human population in northern Europe and a human population in equatorial Africa. Correspond the numbers with the correct populations.
A. Population 1?
B. Population 2?
A. Equitorial africa
B. Northern Europe
132
The free energy diagram refers to a chemical reaction that normally occurs in human cells: A + BC → AB + C. Based on the number of reactants and products and the fact that we are breaking and making a bond, the Delta G (change in free energy between reactants and products) for this reaction is most likely due to changes in:
enthalpy
133
For the same diagram as the previous questions, match the numbers with the correct answers.
1: Exergonic
2: activation energy w enzyme
3: activation energy w/o enzyme
134
Explain the benefits and costs of melanin expression with regards to human fitness, DNA damage and vitamin D
- UV destroys folate, which harms embroys and hurts the ability of people to reproduce healthy offspring (birth defects)
- Lack of UV no catalyze vitamin D
135
Draw a phylogenetic tree with Homo sapiens, Homo erectus, Homo neanderthalensis, chimpanzees
136
Map of the spread of all the types of past humans and other ancestors
137
The following map shows the migration patterns of Homo sapiens from an origin in Africa. Select all indigenous populations for which you expect people to carry Denisovan DNA in their genome.
D, E, F
138
Identify reactions as exergonic or endergonic
Exergonic: release energy
Endergonic: absorb energy
139
Explain a mechanism for how enzymes catalyze reactions
By helping to stabilize the transition state of the reaction
140
Compare and contrast competitive inhibition and allosteric regulation
Competitive – competes for active site
Allosteric – competes for allosteric site
141
Describe allosteric regulation (inhibitors and activators)
Attaches to region and changes the shape
142
Describe how feedback inhibition can regulate amount of product synthesized
Lots of product – allosteric inhibition – i.e PFK
143
Define ‘free energy’ and relate the gain or loss of free energy to reactions in biological systems.
Free energy:Free energy is used to determine how systems change and how much work they can produce.
Gain – endergonic
Loss – exergonic
144
Describe how molecule concentrations, temperature and pH influence enzyme function.
Too high temp – can denature
Too low temp – stop working
Too acidic or basic – denature
NOTE: entropy – change in states
145
Classify bonds as higher or lower potential energy
Nonpolar -- higher potential energy
Polar -- higher energy
146
Classify bonds as higher or lower potential energy
- NADH2 and FADH deposit their electrons into the electron transport chain at complexes I and II, respectively to produce electricity.
- NADH2 and FADH’s electrons attract H+ ions out of the cell, creating a high H+ extracellular concentration that then powers ATP production by a proton gradient.
- ATP contains unstable, high-energy bonds that make it readily hydrolyzed in reactions to release a large amount of energy..
147
Describe the ways that enthaply, entropy, and free energy and equilibrium are understood
148
Explain why carbohydrates function both for energy storage and structure and how the type of linkage (alpha or beta) determines the function
Alpha stores energy and creates helical structures – easy to separate, less stable
Beta leads to structural support and leads to linear structures – hard to separate, more stable
149
Follow the number of carbons in the intermediates of glycolysis, pyruvate processing and the Krebs cycle and be able to describe where and when they are released.
150
Describe how feedback inhibition can regulate respiration
- Lots of product results in inhibition via phosphorylation
- allosteric
151
Sugar, specifically glucose, is not the only energy source used by cells; explain where proteins and fat enter this catabolic pathway.
When there is a lack of carbons, they can also be broken down
152
Draw the electron transport chain
153
Relate the potential energy of an electron to its distance from the nucleus and describe how the potential energy of electrons in C-H bonds is captured as the electrons are moved closer to oxygen in the process of oxidative respiration.
Nonpolar to polar
154
Explain why the electron transport chain is located in a membrane
So that the concentration gradient can be regulated
155
Describe why a concentration gradient contains potential energy.
Moving down it releases energy
156
Predict how different respiratory poisons (that disrupt cellular respiration) would affect a cell or organism.
- Cyanide – ETC is blacked so no oxygen used and no H+ gradient to drive ATP synthase
- Extra protein channel
a. Uses the energy as heat
- Oligomycin – blocks ATP synthase
a. Oxygen will not be consumed and no atp protuced – because the H+ is too high to continue pumping
- DNP – diet pills – carry protons
Oxygen consumed, no ATP
157
Compare and contrast location of proton gradient formation and energy yield in prokaryotes versus eukaryotes
Prok produce slightly more ATP
Prokaryotes is between the cell membrane and the cell wall
Eukaryotes is in the matrix of the mitochondria
158
Identify inputs, outputs and location of fermentation processes
159
Explain how the absence of oxygen forces eukaryotic cells to rely solely on glycolysis for ATP production
The rest of the process would get backed up because of the lack of NAD+ and FADH
Inputs: Glucose – ADP + Pi
Outputs: Alcoholic - Ethanol - CO2 - ATP Lactic Acid - Lactate - ATP
160
Compare the energy yield between aerobic and anaerobic respiration.
Net 2 atp v 29 — 15x fewer
161
Explain the role of fermentation (ethanol and lactic acid formation) for enabling glycolysis.
Regens the NAD+ to allow glycolysis to continue
162
Describe the calvin cycle
LIGHT INDEPENDENT:
Calvin cycle: the 3CO2’s come in. rubsico helps to bind it to make a 3 (6 carbon with 2 phosphorus) structures that is then turned into 6 3-PGA (3 carbon, 1 phosphorus) (CARBON FIXATION) – 6 ATP used, 6 NADPH used to make 6 G3P which is 3 carbons, 1 of which go to make glucose (REDUCTION)
Then REGENERATION: 5 G3P are recycled and 3 ATP are used to create 3 RuBP (5 carbon, 2 phosphorus) to be used for the next cycle
FINAL e- acceptor=NADP+
163
Describe the light dependent
LIGHT DEPENDENT:Normal phosphorylation – photon comes in and excited an electron from water that results in an excited electron in photosystem 2 and a bunch of hydrogen cations that it pumps from the stroma (cytoplasm of chloroplast) to the thylakoid lumen and then in photosystem 2 it is excited again and as it moves down the energy is used to catalyze NADP+ to NADPH — oxygen is final electron acceptor
The hydrogens go through ATP synthase to create ATP
164
Determine the origin and fate of the oxygen and carbon atoms in H2O and CO2 (inputs of photosynthesis) and O2, H2O and glucose (outputs)
The hydrogens in h2o fuel ATP synthase and the oxygen is the o2
Co2 is used the carbon is used to create glucose
165
Explain the processes interrupted by different types of herbicides by analyzing altered inputs and outputs of light-dependent and –independent reactions
If they stopped the work in photosystems 1 or 2 then it would stop the creation of NADPH and ATP which would mean they cant run the calvin cycle so the whole process would stop
166
The following diagram shows the processes of glycolysis, pyruvate processing and the citric acid cycle. The process starts with a six-carbon sugar indicated in the first box. Boxes A, B and C include the carbon-based products of the reactions shown, while letters a, b and c indicate the energy-carrying molecules produced by the reactions. Use the diagram to answer the following questions.
6 carbon sugar box: Glucose
Box A: 2 pyruvates
Box B: 2 carbon dioxides
Box C: 4 carbon dioxides
a and c: ATP molecules
b: NADH molecules
167
What molecule regulates the activity level of PFK (phosphofructokinase)?
ATP
168
Where in bacterial cells would you find ATP synthase?
In the cell membrane
169
Most cancer cells have high rates of glycolysis followed by fermentation to produce most of their energy supply. This is termed the Warburg effect and it allows cancer cells to continue growing even in the absence of blood vessels in tumors. If a tumor cell ran glycolysis/fermentation at the same rate as normal cells run glycolysis/respiration, approximately how much ATP would the cancer cells have relative to normal cells?
Cancer cells would have ~15x fewer ATP than normal cells
170
The basic function of fermentation is:
the regeneration of NAD+ for glycolysis
171
Below follows an overview of photosynthesis. Match the letters with the best description.
A: O2
B: Sunlight
C: photosystem
D: electrontransport chain
E: Chlorophyll
F: protons
G: ATP synthase
H: electrons
I: NADPH
J: CO2
K: Calvin Cycle
172
A technician in a lab maintained isolated chloroplasts in culture, and then treated these with five different herbicides. The following shows the amount of oxygen produced by these chloroplasts when exposed to five different herbicides (H1 to H5). Based on these data, which of the herbicides is mostly likely to affect photosystem II (choose all that apply)?
H-2, H-3
173
In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during ________.
photosynthesis and respiration
174
If photosynthesizing green algae are provided with CO2 containing heavy oxygen (18O), later analysis will show that all of the following molecules produced by the algae contain 18O EXCEPT ________.
O2
175
The final electron acceptor in the light capturing reactions of photosynthesis is:
NADP+
176
Alcoholic/Ethanol Fermentation in yeast
177
For every ___ electrons that pass from NADH to CoQ, __ H+ are pumped out into
the inter membrane space.
2, 4
178
The loss of hydrogen or electrons is known as
oxidation
179
C6H12O6 + 6O2 --> 6H2O + 6CO2 + 38 ATP -- this is known as
(d) oxidation and is exergonic
180
Where does the electron transport chain occur?
cristae membrane
181
Describe the different levels of ecological study: organismal, population, community, ecosystem, global
1. Organismal
a. How to individuals interact with each other and their physical environment
2. Population
a. How and why does population size change over space and time
3. Community
a. How do species interact with other species
4. Ecosystem
a. How does energy flow through the envo
5. Global
a. How is the biosphere affected by global changes in nutrient cycling and climate?
182
Explain what primary productivity is and how energy moves up trophic levels and why energy is lost moving up trophic levels
- Primary productivity: primary producers are the basis for all organisms as they create all the energy in the system
- Gross primary productivity: the total amount of chemical energy produced in a given area and time period
- Why do we lose so much sunlight? Photopigments can only do some, its reduced in the winter, and the efficiency of enzymes are temp dependent
55 percent is in cellular respiration; 45 percent in NPP (k2 reproduction and growth) – net primary productivity is stored in the form of biomass
- Primary producer → primary consumer/decomposer → secondary consumer → tertiary consumer. Heat is lost in every movement between.
- Biomass is highest for primary producers. Only 10 percent of biomass is passed from 1 to the next trophic level. The vast majority of the energy is lost due to cellular respiration.
183
Explain why temperature and precipitation vary across the globe
Temp and precip are the main drivers of biomes – when there is lot of water and lots of sunlight you see greater net primary productivity for plants to use
184
Describe the main biotic and abiotic factors that define terrestrial and aquatic and marine biomes: precipitation and temperature create different biomes; tropical rainforests most productive due to high temperature and high precipitation
K2 primary productivity – rainforest is the most productive
185
Explain why tropical rain forests and open ocean contribute most to the earth’s primary productivity
- Tropical rain forest – lots of rain, lots of temp
- Primary productivity is USUALLY higher on land because there is not enough light of the right wavelength (chlorophyll absorb red and orange light)
- Net primary productivity per unit area – Open ocean 1 because of HOW BIG it is, tropical rainforest is next
186
Distinguish between bottom-up and top-down (trophic cascade) control of primary productivity
Bottom up: Primary productivity – Trophic levels are influenced by producers, who are at the bottom of the food chain
Top-down: Trophic cascade – Trophic levels are influenced by top predators of the food chain
187
Explain how biologists measure biodiversity and explain the difference between species richness and species diversity
Biodiversity is measured through a combination of species richness and species diversity - Species richness is how many different species there are in a community - Species evenness is the relative abundance of each species - These two measures can be combined using mathematical indices - Biodiversity increases as you approach the equator and decreases as you get further from it
188
Describe the latitudinal gradient of biodiversity
The latitudinal diversity gradient describes the fact that there are less species in the temperate regions than in the tropics.
189
Explain the diversity-productivity relationship
Productivity increases with diversity
190
explain the facilitation effects
The facilitation effect: Facilitation occurs when one species positively impacts the fitness of another. The facilitated species grows better in the presence versus absence of the other species.
191
explain the sampling effects
The sampling effect is: if a certain big producer is present then biomass in a plot is high. If the big producer is absent, biomass is low
192
Explain the resource use efficiency
Resource use efficiency (RUE) is how well resources are used
193
explain the roles of keystne species. use examples
Keystone species: A keystone species is an organism that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether. Common keystone species: beavers and sharks
194
Describe the ecosystem services to humans provided by diverse communities: provisioning, regulating, cultural, supporting
1. Provide Raw Materials Example: medicine
2. Regulating Services: stabilize our ecosystem Example: O2 and CO2 and climate regulation
3. Cultural Services: enrich liÿe equality Example: aesthetics
4. Supporting Services Example: pollination
195
Predict the effects of the following on biodiversity: habitat destruction, overexploitation, invasive species, pollution, climate change
1. Habitat Destruction Example: melting the Arctic
2. Overexploitation Example: Overfishing
3. Introduce invasive species that harm native species Example: zebra mussels
4. Climate Change Example: Rising temperatures
5. Pollution: introduce abiotic factors that harm live We are making the Earth uninhabitable for the great biodiversity that supports this planet.
196
Explain why scientists conclude that humans are causing a sixth mass extinction
There is a higher rate of extinction since the extinction that killed the dinosaurs, and that is due to habitat destruction, overexploitation, pollution, climate change and invasive species
197
Define global climate change and describe its causes
Climate change: Climate patterns change in terms of time and location.
Causes: Greenhouse Gases, variations in the sun’s output of energy, dust and Gases from volcanic eruptions
198
Explain the relationship between greenhouse gases and temperature
The more greenhouse gases, the higher the global temperature. This is because they trap the heat ÿrom the sun instead of letting it escape back out into space
Atmosphere is the smallest carbon reservoir.
199
Describe the global carbon cycle, and explain the impact of atmosphere, carbon sinks, reservoirs, fossil fuels, photosynthesis, respiration, deforestation and fossil fuel use on the carbon cycle
-Atmosphere is the smallest carbon reservoir.
-Photosynthesis brings carbon into water and land.
-Respiration takes carbon away from land and water into atmosphere.
-Deforestation and fossil fuel use add to carbon in atmosphere.
-Land and water act as carbon sinks
-Human activities disrupt the global carbon cycle.
--Deforestation: less photosynthesis that consumes co2, fossil fuel use
200
Explain how human activities impact climate change by disrupting the global carbon cycle
Human activities disrupt the global carbon cycle.
Deforestation: less photosynthesis that consumes co2, fossil fuel use
201
Describe the following 6 lines of evidence for a universal common ancestor and explain how they provide evidence for a universal common ancestor: Chirality of sugars and amino acids, common amino acid and nucleotide building blocks, common units of energy currency, common metabolic pathways, universal genetic code, common genes.
- Chirality of sugars and amino acids: life only uses left handed AA’s and right handed sugars
- common amino acid and nucleotide building blocks: all life uses only 20 amino acids despite the unlimited combinations
- common units of energy currency: all use ATP
- common metabolic pathways: all use cellular respiration
- universal genetic code: all known life uses the same genetic code which makes sense if it was all inherited from a common ancestor
- common genes: MC1R is common in many species! Some are common to almost all of them. 355 core genes are widely shared
202
List and explain why the following provide evidence for an RNA-world: RNA’s dual functions of catalyst and genetic information, RNA’s role in core cellular functions (transcription, splicing and translation), RNA’s role as key metabolic molecules (ATP, Acetyl-CoA, NADH), existence of RNA viruses)
- RNA’s dual functions of catalyst and genetic information
- RNA’s role in core cellular functions (transcription, splicing and translation)
- RNA’s role as key metabolic molecules (ATP, Acetyl-CoA, NADH): RNA is used as lies energy currency, plays a part in acetyl; CoA, and NADH
- existence of RNA viruses
203
Discuss the structures formed by amphipathic lipids in water and how this supports origin of life
These form micelles and create a membrane sphere
204
What organelle is present in all cells
Ribosomes
205
Label A, B, C
A: Mitochondrion, B: nucleus, C: cell membrane, D: nucleolus, E: vesicle, F: rough endoplasmic reticulum
206
You have a lipid bilayer with equal amounts of saturated and unsaturated phospholipids. After testing the permeability of this membrane to glucose, you increase the proportion of unsaturated phospholipids in the bilayer. What will happen to the membrane's permeability to glucose in this experiment?
Permeability to glucose will increase.
207
What explains why various cells of different tissue types can look so different from each other and perform very different functions?
Different cells have different numbers of each organelle.
208
Researchers supplied a short pulse of radioactively labeled leucine, followed by a long chase of unlabeled leucine, to cells that secrete digestive enzymes. The bulk of the radioactive label was initially found in the rough endoplasmic reticulum (ER), then in the Golgi apparatus, then in secretory vesicles, and finally outside the cell. These results support which of the following hypotheses?
Secreted proteins are synthesized in the rough ER and travel through the Golgi apparatus to be packaged into secretory vesicles that fuse with the plasma membrane.
209
Which of the following is a true statement regarding viruses:
A. Viruses can use either DNA or RNA as hereditary material
B. Viruses can carry out transcription independently (without using the host cell)
C. Viruses have a cell membrane
D. Viruses can carry out translation independently (without using the host cell)
A
210
According to the Endosymbiont hypothesis, which organelles in eukaryotes used to be free-living organisms?
Chloroplasts and mitochondria
211
What is the function of reverse transcriptase in retroviruses?
It uses viral RNA as a template for DNA synthesis
212
The first Gap phase (G1) of the cell cycle is:
necessary to allow for synthesis of organelles and cytosol.
213
The figure shows a karyotype of a human. Use the figure to answer the following questions.
a. number of chromosomes?
b. number of chromatids
c. number of DNA helices
a. 46
b. 92
c. 92
214
Here is a karyotype of a human male with 47 chromosomes instead of the common 46 chromosomes. This condition could be caused by non-disjunction in (choose all that apply):
A: Meiosis 1 of father
B: Meiosis 1 of mother
C: Meiosis 2 of father
D: Meiosis 2 of mother
A, B, D
215
Which of the following student models would be the most useful for illustrating the principle of independent assortment?
B
216
A single human can produce about 8.4 million different gametes through independent assortment. During fertilization, egg and sperm cells come together at random. How many genetically different offspring are possible through independent assortment and random fertilization?
8.4 million × 8.4 million = 70.6 × 10^12
217
An advantage of asexual reproduction is that it ________.
enables the species to rapidly colonize habitats that are favorable to that species
218
With which of the following statements would a biologist be most inclined to agree?
A. Humans and other apes represent divergent lines of evolution from a common ancestor.
B. Humans evolved from Old World monkeys.
C. Humans represent the pinnacle of evolution and have escaped from being affected by natural selection.
D. Humans evolved from chimpanzees.
A
219
The graphs show histograms for pair-wise mitochondrial genetic divergence between randomly picked individuals of gorillas, western chimpanzees and humans. Choose the plot that shows the data for humans.
top
220
2-deoxy-D-glucose (2DG shown below) is a drug being tested to treat cancer. It is a glucose molecule where a hydroxyl group has been replaced by hydrogen. 2DG binds to the active site (substrate-binding site) of an enzyme in the glycolysis pathway but cannot undergo the enzymatic reaction. 2DG is thus an example of:
competitive inhibition
221
Choose the right combination of words to correctly complete the sentence below:
2DG can____ (easily/not easily) throug the cell membrane because it is ____ (polar/not polar), thus it will enter cells via____ (active/facilitated/simpe diffision)
not easily, polar, facilitated
222
Which best describes how enzymes catalyze reactions?
A. By binding strongly to the products of the reaction
B. By donating atoms to the substrates
C. By covalently binding to the substrates
D. By helping to stabilize the transition state of the reaction
D
223
The graph shows the change in Gibbs free energy in a chemical reaction. What can we conclude, knowing that the number of reactants equals the number of products?
Enthalpy increased
224
Red blood cells are the most abundant cell in your body and they are full of hemoglobin that carries oxygen to deliver to cells throughout your body. Which process in your cells directly uses oxygen?
oxidative phosporylation and electron transport chain
225
In a eukaryote, the first fully oxidized carbon released from the breakdown of a glucose molecule is produced during ______ and is formed in __________ .
pyruvate processing (link rxn) and mitochondria
226
Cancerous tumors are often partially anaerobic due to the fact that the blood vessels supplying them are not sufficient to provide adequate amounts of oxygen. Which of the following would be true for tumor cells under these conditions?
The production of lactic acid would increase in these cells.
227
Cyanide is a nasty poison that blocks Component IV (cytochrome oxidase) of the ETC. What will happen if you add cyanide to cells that are actively carrying out respiration?
Oxygen will not be consumed, and no ATP will be produced.
228
If shading matters on a pedigree, how does that change predictions?
You can eliminate some probabilities
229
Charles Darwin and John Baptiste Lamarck would have agreed on the following (choose all that are correct):
- Life probably arose just once on earth, then subsequently diversified.
- Complex animals, like humans, are more evolved (higher) than simpler organisms, like bacteria.
230
According to the tree, the synapomorphy that defines the reptiles (turtles, snakes, lizards, crocodiles) and birds is:
eggs w shells
231
How many peptide bonds are in the following polypeptide? And how many amino acids?
2, 3
232
Which of the following would properly base-pair with the sequence AAAGCGCT?
AGCGCTTT (they did not specify, therefore the top is written 3-5 so you have to flip it to go from 5-3)
233
Below are four pictures, indicated with A-D. Which of these is not considered a cell?
D
234
For the following pictures, match the correct structures/organelles with the numbers and arrows.
1: vacuole
2: chloroplast
3: cell wall (its bacteria)
4: mitochondrion
5: nucleus
235
Match the molecules with the correct description.
A. amino acid
B. nucleotide
C. lipid
D. lipid
E. nucleotide
F. Amino acid
G. Lipid
H. Carbohydrate
236
Rainbow trout have different cell membranes based on the temperature they live in. Match the lipid bilayer with the correct temperature.
short, unsaturated: cold temps
long and saturated: warm temps
237
You have grown a culture of human cells and discover that it is heavily contaminated with bacteria. Which of the following procedures will most likely eliminate the bacteria without killing the human cells?
Treating the culture with a drug that inhibits the formation of cell walls.
238
Which of the following characteristics, structures, or processes is common to bacteria and viruses?
Genetic material composed of nucleic acids
239
Which of the following proteins would be made on ribosomes that are attached to the rough endoplasmic reticulum?
insulin, which is secreted from the cell
240
Which of the following would support the argument that viruses are non-living?
They are not cellular.
241
In electron micrographs of herpes simplex virus (HSV) infection, such as shown here, the intact virus initially reacts with cell-surface proteoglycans, then with specific receptors. This is later followed by viral capsids docking with nuclear pore complexes (NPC). Afterward, the capsids go from being full to being "empty." Which of the following best fits these observations?
The viral envelope mediates entry into the cell, the capsid mediates entry into the nuclear membrane, and the genome is all that enters the nucleus.
242
DNA replication is said to be semiconservative because:
Each new DNA molecule is composed of one old strand and one new strand.
243
The following graph shows how cellular DNA content changes over the course of a typical cell cycle of rapidly proliferating human cells. Which of the phases indicted with A, B, C or D is S phase?
B
244
During mitosis, it is necessary for the nuclear envelope of the parent cell to disintegrate. This is accomplished in part by phosphorylation of proteins associated with the nuclear envelope. If the enzyme responsible for that phosphorylation event is inhibited, at which phase of mitosis are cells likely to arrest?
Prophase
245
The following picture shows a cell undergoing different stages of meiosis. Match the numbers with the correct structures.
1: sister chromatids
2: metaphase plate
3: spindle
4: chiasmata
5: homologs
246
The following picture is most likely the following phase of meiosis:
metaphase 1
247
The bulldog ant is diploid and has two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. Diversity in this species may be generated by mutations and ________.
crossing over
248
The picture shows a karyotype of a human male with 47 chromosomes instead of the common 46 chromosomes. This condition is most likely caused by non-disjunction in_____.
Meiosis II of the father
249
Which of these species had members who moved out of Africa? Choose all that apply.
Homo erectus, Homo sapiens
250
Lactase is the enzyme that breaks down the milk sugar lactose into galactose and glucose. In most mammals and humans, this enzyme is only produced in babies that feed off breast milk. Older children and adults then no longer produce the enzyme, and suffer stomach and intestinal upset (lactose intolerance) when consuming milk. In many human populations, however, adults can drink milk because they keep producing the enzyme; this is referred to as lactase persistence. Graph A shows the association between the level of pastoralism (keeping of domestic animals such as sheep, goats or cows) and the frequency of lactase persistence across a number of human populations (each data point is a population). Graph B shows the relationship between lactase persistence and estimated human population density in the year 1500. Based on these data, explain the evolution of lactase persistence, making specific reference to natural selection and human fitness.
As pastoralism increased, milk became more common in the human diet, and increased as an essential nutrient source. There is variation in lactase persistence across people. Those with lactate persistence could break down the milk and get access to glucose, increasing their ability to survive by creating more energy, thereby increasing their fitness over those who are unable to break down milk into glucose that can be used for energy. Those that survived were more likely to have lactase persistence because they would more readily be able to make ATP to survive while some others would die due to a lack of glucose (starvation), so those individuals with lactase persistence were more likely to reproduce. That changes the frequency of the allele in the population as time goes on, where the reproduction is in favor of the increase in fitness provided by lactase persistence past childhood.
251
The following shows the summary equation of respiration. Use this equation to answer the following questions.
The reactants will have ___ (more/less) potential energy than the products.
During this prcess, entropy___ and enthalpy___.
Overall, it is ___ (ender or exergonic)
more, increases, decreases, exergonic
252
When oxygen is not available to a muscle cell, NADH formed during glycolysis does not pass electrons to the electron transport system. Instead, which molecule below serves as the electron acceptor?
pyruvate
253
The chemical 2,4-dinitrophenol (DNP) was used extensively in diet pills in the 1930s because it was shown to increase metabolic rate. We now know that DNP overdose will cause fatal hyperthermia making this drug unsafe for human consumption, but the toxin is still used in manufacturing of dyes, wood preservatives, explosives, and insect control substances. DNP acts as a “protonophore” that pokes holes in the inner mitochondrial membrane. What effect will DNP exposure have on cellular metabolism?
Protons will leak across the inner mitochondrial membrane bypassing ATP synthase
254
In a cell exposed to 2,4-dinitrophenol (DNP; see previous question), how many ATP molecules (total net) would be generated per molecule of glucose?
4 (2 from glycolysis, and 2 from CAC)
255
In the following model, match the boxes labeled A, B and C with the correct descriptions.
A: NADH
B: NAD+, H+
C: O2
256
Charles Darwin and John Baptiste Lamarck would have agreed on the following (choose all that are correct):
- The earth is old
- Modern day organisms have evolved from different, previous, species
257
Charles Darwin and Alfred Russell Wallace both came up with the theories of descent with modification and natural selection. While their theories had aspects in common, they also disagreed on some elements. Explain their disagreement on domestication.
Darwin believed domestication provided a test case for natural selection, while Wallace thought domestication produced unfit animals that would never survive in the wild and therefore did not provide evidence for natural selection.
258
Eukaryotes have linear chromosomes in a nucleus, while prokaryotes have circular chromosomes without a nucleus. The nucleus is a...
The possession of a nucleus is a synapomorphy that defines the eukaryotes.
259
We previously discussed hurricanes and lizards. Scientists measured the toepad size of lizards before and after two major hurricanes made landfall on the islands Pine Cay and Water Cay in 2017. In 2019, the scientists went back to the islands and measured the toepads of lizards again (Donihue et al 2019 PNAS). At this time, the scientists could measure the toepads of lizards that had survived the hurricanes, but also of lizards that were born since that time. The figure shows the data you saw before (lizards measured before and after the hurricanes in 2017) AND new data on the toepad size of lizards that were born since 2017 (indicated with 2019). Based on this updated data set, choose all Darwin's postulates that are supported by these data.
All 4 posulates
260
Cystic fibrosis is a genetic disease caused by a recessive allele; individuals with the disease are homozygous recessive. The pedigree shows that individual 5 has the disease. Neither of her parents (individuals 1 and 2) had the disease. Note that when individuals are denoted with question marks, their shading does not provide information on their genotype. In contrast, for individual 3, the shading does provide information on her genotype. Based on this pedigree and the provided information, individuals 1 and 2 must have the following genotypes.
Prob that 4 has cystic fibrosis: 25 percent
Prob that 4 is a carrier: 50 percent
261
Oldfield mice are brown and inhabit old agricultural fields, while blond beach mice inhabit sand dunes. Below follow the CODING sequences of part of the MC1R gene of these mice. Using the Genetic Code table, determine the amino acid sequences of the part of the MC1R protein gene encoded by this DNA sequence.
Just change the T's to a U and then do the coding sequence
262
What makes RNA more reactive than DNA?
2' OH group on the ribose sugar
263
Which of the following would properly base-pair with the sequence GATCTGCC?
GGCAGATC
264
Suppose Hershey and Chase had labeled bacteriophages with radioactive nitrogen. Briefly explain whether they would have been able to determine whether DNA or proteins carry genetic information.
They would not have been able to determine whether DNA or proteins carried the genetic information because both DNA and Proteins have nitrogen (DNA nitrogenous base, protein amino group) which means no matter what there would have been a trace in the second generation, and the whole vial would have looked like like the radioactive trace because the shells AND the code all have nitrogen in them. They wouldn't be able to discern which is which.
265
The picture shows base-pairing in a double-stranded DNA molecule. Choose all the letters where you would find a hydrogen bond in that location.
All but c
