Final study set Flashcards
Adenine bonds to…
Thymine
DNA v RNA
DNA: double helix, phosphate, 5-carbon sugar, nitrogenous base, AT, GC
RNA: Single strand, AU, GC
Darwin v Lamarck
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
How did Darwin and Wallace come up with their theory?
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
Darwin v Wallace
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
Describe how their theories were different from existing theories
- 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
Why does the earth have to be old?
Earth is about 4.5-4.6 billion years old, so plenty of time to evolve
List key elements of darwins theories
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.
Describe the 8 lines of evidence
(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
How to write the name of a species?
Genus then species italicized (the whole thing)
How do you make a phylogenetic tree?
Use homologous traits
Define homoplasy
Homoplasy is convergent evolution. Homology is evolving from the same ancestor and having the same features.
Define synapomorphy
- 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
Explain the synapomorphies that define the three domains of life: bacteria, archaea, eukarya
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
Create a relative timeline for the evolution of life on earth
- 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!
Explain the causes of diversification during the Cambrian explosion
- 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
Describe Darwin’s 4 postulates
(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
Explain how anti-biotic resistant bacteria show evidence for Darwin’s 4 posulates
- 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
What are some tips and tricks on how to identify Darwin’s 4 postulates based on the graph given?
- 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
Describe adaptations and fitness
Adaptations: a trait in an individual that is heritable and increases fitness
Fitness: overall ability for an individual to survive and reproduce fertile offspring
What are common misconceptions on nature selection and why are they dumb?
(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
Explain some experiments to test the adaptive value of a trait
(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
What are the core differences between adaptations and natural selection? Also what is adaptive radiation?
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)
Which is archaeopteryx most closely related to? Enantiomithes, Aurornis, Dromaeosauridae
Enantiomithes
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
Do archaea and bacteria (prokaryotes) form a monophyletic group?
No
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
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
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
How can evolutionary fitness be estimated?
Count the number of healthy, fertile offspring produced
Which postulate is not represented? If any?
Traits are heritable
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
Describe the inheritance patterns of a single trait
Dominant + Heterozygous = Dominant
Recessive requires both alleles to be recessive
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.
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.
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.
If you have tall parents that have a 3 tall:1 short ratio of offspring; is tall dominant or recessive
dominant
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
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)
How to tell if it is autosomal dominant
- Never skips a generation
- Equal probability for men and women
How to tell if it is Autosomal recessive
- Skips a generation
- Equal prob for women and men
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
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
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
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
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
This is an autosomal rec trait. What is the genotype of II 1?
Aa
What is the probability that II 3 and 4 will have a child with the disease?
50 percent
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
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
If the ratio must be 1:1:1:1 with 2 traits, R and V, what is the parental genotype?
RrVv x rrvv
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
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
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
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
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
Classify molecules as more hydrophobic or hydrophillic
If they are polar – hydrophillic, if they are nonpolar – hydrophobic
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)
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
What does amphipathic mean?
Has a polar and a nonpolar end
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
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
Explain what evidence led to the discovery of DNA structure.
Photo 51, chemistry base pairing understandings
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
What bases are purines?
Adenine and Guanine they bond 3 times
What bases are pyrimadines?
Cytosine, Thymine, and Uracil
What are the 3 parts of a nitrogenous sugar?
Deoxyribose (sugar), phosphate group, nitrogenous base
What is the 3 end and what is the 5 end?
3rd carbon v 5th carbon
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)
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.
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.
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
Identify chemical properties of amino acids
Have amine group, an H group, carboxyl group, and R side chain
Identify locations of peptide bonds and R groups (side chains) in peptide chains
The R side chain is between the carboxyl and amine group
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
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
Draw the structure of an amino acid and a dipeptide.
It occurs between the carboxyl group and the amine group through dehydration synthesis.
Describe how DNA can encode the primary sequence of an amino acid via an RNA intermediate
DNA template → DNA coding → mRNA → AA’s
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
translate a messenger RNA into a peptide sequence
Divide into codons
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
T bonds to A, how many times
2
G bonds to C, how many times
3
Convert this DNA sequence: ACT CCT GAG GAG AAG to
Thr-Pro-Glu-Glu-Lys
Convert this DNA sequence: ACT CCT GTG GAG AAG
Thr-Pro-Val-Glu-Lys
Thr-Pro-Glu-Glu-Lys –> Thr-Pro-Val-Glu-Lys. what type of mutation is this?
missense mutation
What interactions occur in the secondary structure?
Alpha helix or beta pleated sheets – H bonds form on the backbone
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
Describe Cell Theory
- All living organisms are made up of cells
- Cell is the basic unit of life
- Cells arise from preexisting cells
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
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
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
Choose the molecule that would most easily pass through a phospholipid membrane (assume no pores/channels/pumps).
B
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
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
Describe endosymbiont hypothesis
The endosymbiotic theory states that mitochondria and chlopoplasts in today’s eukaryotic cells were once separate prokaryotic microbes.
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
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
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
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
Describe the endomembrane system
Free ribosome, RER, Golgi, Vesicles
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
Explain whether viruses are alive based on cell theory
NOT ALIVE – CANNOT REPLICATE
Lysis cycle vs lysogenic
How many double helices are shown in the picture?
8
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
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
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
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.
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
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
Which of the following student models would be the most useful for illustrating the principle of independent assortment?
B
Place the pictures of meiotic stages in the right order.
B -> E -> D -> A -> C
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
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
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
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
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
Draw a phylogenetic tree with Homo sapiens, Homo erectus, Homo neanderthalensis, chimpanzees
Map of the spread of all the types of past humans and other ancestors
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
Describe the ways that enthaply, entropy, and free energy and equilibrium are understood
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.
Draw the electron transport chain
Identify inputs, outputs and location of fermentation processes
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+
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
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
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
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
Alcoholic/Ethanol Fermentation in yeast
Label A, B, C
A: Mitochondrion, B: nucleus, C: cell membrane, D: nucleolus, E: vesicle, F: rough endoplasmic reticulum
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
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
Which of the following student models would be the most useful for illustrating the principle of independent assortment?
B
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
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
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
According to the tree, the synapomorphy that defines the reptiles (turtles, snakes, lizards, crocodiles) and birds is:
eggs w shells
How many peptide bonds are in the following polypeptide? And how many amino acids?
2, 3
Below are four pictures, indicated with A-D. Which of these is not considered a cell?
D
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
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
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
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.
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
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
The following picture is most likely the following phase of meiosis:
metaphase 1
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
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.
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
In the following model, match the boxes labeled A, B and C with the correct descriptions.
A: NADH
B: NAD+, H+
C: O2
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
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
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
