Biology Flashcards
1
Q
When did life on Earth begin?
A
Approximately 3.5-4 billion years ago.
2
Q
What are the levels of biological organization?
A
- atoms
- molecules and macromolecules
- cells
- tissues
- organs
- organism
- population
- community
- ecosystem
- biosphere
3
Q
natural selection
A
when a mutation causes a beneficial change in survival or reproduction and the frequency of that mutation increases across generations
4
Q
Prokaryote
A
simple cell structure
- bacteria
- archaea
5
Q
eukaryote
A
Larger cells with internal compartments that serve various functions. Cells have a nucleus
- protists
- plants
- fungi
- animals
6
Q
What are the taxonomic levels?
A
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
7
Q
genome
A
complete genetic composition of an organism
8
Q
proteome
A
all of the proteins that a cell or organism can make
9
Q
theory
A
broad explanation of some aspect of the natural world that is substantiated by a large body of evidence
10
Q
What are the types of particles within atoms?
A
- protons (in atomic nucleus)
- neutrons (in atomic nucleus)
- electrons (in orbitals at various distance from the nucleus)
11
Q
ion
A
atom that has gained or lost one or more electrons
12
Q
valence electrons
A
electrons in the outermost shell of the atom
13
Q
atomic number
A
given based on the number of protons the element has
14
Q
isotopes
A
elements that differ in the number of neutrons
15
Q
radioisotopes
A
unstable isotopes that persis for a long time and lose energy by emitting subatomic particles and/or radiation
16
Q
What elements are living organisms mainly made of?
A
- oxygen
- carbon
- hydrogen
- nitrogen
17
Q
trace element
A
present in extremely small quantity but is essential for normal growth/function
-example: iron
18
Q
covalent bond
A
atoms share electrons
- can occur between atoms whose outer shells are not full
- strong bonds
19
Q
polar covalent bond
A
one atom is more electronegative that the other and shared electrons create poles with one atom more negative than the other
20
Q
nonpolar covalent bond
A
bond between atoms with similar electronegativities
21
Q
hydrogen bond
A
hydrogen atom from one polar molecule becomes electrically attracted to the electronegative atom in another polar molecule
-weak on their own but strong if there’s enough of them (ex: in DNA)
22
Q
van der Waals forces
A
short-lived electrical attraction due to unevenly distributed electrons in orbit
23
Q
ionic bond
A
bond between negative and positive ions
-bond easily broken in water
24
Q
cation
A
ion with net positive charge (lost and electron)
25
anion
ion with net negative charge (gained electron)
26
chemical reaction
one or more substances are changed into other substances
| -requires energy (usually heat)
27
Brownian motion
heat energy causing atoms and molecules to vibrate/move
28
catalyst
substance that speeds up a chemical reaction
| -ex: enzyme
29
What are the properties of water?
- ions and polar molecules readily dissolve in water
- water is a polar covalent bond
- high specific heat - amount of heat needed to raise temperature
- cohesion - water molecules attract to each other (hydrogen bonds)
- adhesion - water attracted to and adheres to a surface that is not electrically neutral
30
organic molecule
carbon-containing molecule
| -lipids, carbs, proteins, nucleic acids
31
urea
natural organic product formed from the breakdown of proteins in an animals body
32
How many covalent bonds can carbon form?
4
- 4 electrons in outer shell, wants 8 total
- can form non-polar and polar covalent bonds
33
isomers
2 structures with an identical molecular formula but different structures and characteristics
34
What are carbohydrates used for in the body?
They are used for energy! To make ATP!
They circulate blood into cells. Inside cells, enzymes break down glucose into smaller molecules. This releases energy stored in the bonds that are breaking down. This new energy is then stored in the bonds of ATP.
35
polysaccharides
"many sugars"
- starch, glycogen
- used to store energy in cells
- can be broken down to sugars, which can be broken down to make ATP
36
Are lipids hydrophilic or hydrophobic?
Hydrophobic!
37
How are fats (triglycerides) formed?
Bonding glycerol to 3 fatty acids
38
fatty acid
a chain of carbon and hydrogen atoms with a carboxyl group (-COOH) at one end
39
saturated fatty acid
all carbon in the fatty acid are linked by single covalent bonds. They can pack together tightly
40
unsaturated fatty acid
At least one of the carbon bonds are linked by a double covalent bond. unsaturated fatty acids cannot pack together tightly
41
What are fats used for?
They store energy. Hydrolysis of triglycerides releases the fatty acids from glycerol. The fatty acids can be metabolized to provide energy to make ATP
42
phospholipid
The third hydroxyl group of glycerol is linked to a phosphate group instead of a fatty acid. This makes one end polar/hydrophilic and the other end is hydrophobic. This causes them to be organized into bilayers
-cell membranes
43
steroid
- lipid with a skeleton that has 4 fused rings of carbon atoms
- different than other types of lipids
- cholesterol is converted to other steroids by modifying side groups
- one or more hydroxyl groups are attached to the ring structure, but not enough to make a steroid water soluble
44
What elements are proteins made of? What are the building blocks of proteins?
- made of C, H, O, N, and small amounts of other elements (sulfer)
- polymers of amino acids
45
peptide bond
covalent bond formed between a carboxyl and amino group
46
polypeptide
many amino acids joined by peptide bonds
47
protein
1+ polypeptides that have been folded and twisted into a certain 3D shape to do a particular function
48
protein primary structure
amino acid sequence in straight line
49
protein secondary structure
amino acid sequence is folded into more complex structure
50
protein tertiary structure
polypeptide folds and refolds upon itself to assume a 3D shape
51
protein quaternary structure
2+ polypeptides of tertiary structure assembled with each other
-ex: hemoglobin (4 protein subunits)
52
nucleic acids
responsible for the storage, expression, and transmission of genetic info
-polymers that are made of neucleotides
53
What are the building blocks of nucleic acids?
Nucleotides
54
What are the two classes of nucleic acids?
- deoxyribonucleic acid (DNA)
| - riboneucleic acid (RNA)
55
DNA
stores genetic info coded in the sequence of their monomer building blocks (nucleotides)
56
RNA
involved in decoding DNA info into instructions for linking specific sequence of amino acids to form a polypeptide chain
57
What are the bases (nucleotides) of DNA?
```
purine bases
-adenine
-guanine
pyrimidine bases
-cytosine
-thymine
```
58
What are the bases (nucleotides) of RNA?
```
purine bases
-adenine
-guanine
pyrimidine bases
-cytosine
-uracil
```
59
prokaryote
- simple cell structure
- lack a mambrane-enclosed nucleus
- bacteria and archaea
60
plasma membrane
double layer of phospholipids and embedded proteins
| -barrier between cell and external environment
61
cytoplasm
region of cell contained within the plasma membrane
62
ribosome
involved in polypeptide synthesis
63
cell wall
relatively rigid structure that protects plasma membrane and cytoplasm
-porous
64
organelle
membrane-bound compartment with its own unique structure and function
65
nucleus
where most of DNA is housed
66
cytosol
outside the organelles but inside the plasma membrane. The fluid in the cytoplasm.
-metabolism occurs here
67
metabolism
sum of chemical reactions by which cells produce the materials and utilize the energy necessary to sustain life
68
catabolism
breakdown of molecules into smaller components
69
anabolism
synthesis of cellular molecules and macromolecules
70
cytoskeleton
network of 3 types of protein filaments (microtubles, intermediate filaments, actin filaments)
-provides cell shape, organization, and movement
71
motor proteins
proteins that use ATP as a source of energy to promote movement
-interact with cytoskeletal filaments to promote movement
72
nuclear envelope
double-membrane structure that encloses the nucleus
73
nuclear pores
provide passageway for movement of molecules/macromolecules into/out of nucleus
74
chromosome
composed of DNA and proteins that help to compact the chromosome to fit in nucleus
75
chromatin
chromosome-protein complex
76
What is the function of the nucleus?
protect, organize, replicate, express DNA
| -assemply of ribosome subunits
77
nucleolus
where the assembly of ribosom subunits occurs
78
rough endoplasmic reticulum
key rold in sorting proteins that are destined for the endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, plasma membrane, or outside of the cell
79
smooth endoplasmic reticulum
provides increases surface area for key enzymes that play important metabolic roles
- enzymes in smooth ER are critical in synthesis and modifications of lipids (estrogen and T production)
- sit of detoxification
80
Golgi apparatus
- processing and modifying certain proteins and lipids
- protein sorting
- secretion of materials (package of materials into secretory vesicles that later fuse with the plasma membrane to release contents)
81
lysosome
small organelles in animal cells that lyse/break macromolecules
82
vacuoles
temporarily store or transport materials in animal cells
83
peroxisomes
catalyze the breakdown of harmful molecules
84
What are the characteristics of the cell membrane?
- semi-permeable (plasma membrane proteins transport nutrients, ions, etc. into-out of cell
- cell signaling (cell membrane receptors get signals (environmental, hormones) that triggers cell to have a response
- cell adhesion (proteins on mombranes can allow cells to interact)
85
semiautonomous organelles
can grow and divide to reproduce themselves
- mitochondria and chloroplasts (plants only)
- have their own DNA
- divide by binary fission (splitting in 2)
86
mitochondrian
site where ATP is made
- convert chemical energy stored within covalent bonds of organic molecules into a form (ATP) that can be readily used by cells
- involved in synthesis, modification, breakdown of several types of molecules (synthesis of certain hormones)
- have their own DNA
- divide by binary fission (splitting in 2)
87
protein sorting signals
short stretches of amino acid sequences on proteins that direct them to their correct cellular location
88
protein cotranslational sorting
translation at ribosome halts until ribosome binds to the endoplasmic reticulum membrane
-translation resumes and protein is sorted by ER
89
protein post-translational sorting
sorting does not occur until translation is finished
90
What are the primary components of cell membranes?
- phospholipids
- proteins embedded or attached to membrane
- carbs (lesser component)
91
Described the phospholipid bilayer (polarity etc.)
- hydrophilic (polar) head on surface
- hydrophobic (nonpolar) tails on interior
- because of hydrophobic interior, membrane is a barrier to movement of ions and hydrophilic molecules
92
Why is the phospholipid bilayer semi-fluid?
- it's short tails are less likely to interact with each other (makes them more fluid)
- fatty acid tail are unsaturated fats (have double bond) which make membrane more fluid and makes interactions more difficult
- cholesterol is present and is rigid
93
How does the cholesterol in the plasma membrane make it more or less fluid with changing temperature?
- at higher temperature, cholesterol makes membrane less fluid
- at lower temperature, cholesterol makes membrane more fluid (prevents freezing)
94
What is the advantage of plasma membrane being semi-permeable?
ensures essential molecules enter cell, metabolic intermediates remain in cell, waste products exit cell
95
diffusion
sustance moves from region of higher concentration to region of lower concentration
-passive transport
96
facilitated diffusion
transport proteins provides a passageway for the substance to cross the plasma membrane
-passive transport
97
passive transport
transport of a substance across a membrane from a region of high concentration to low concentration
-does not require input of energy
98
active transport
moves substance from an area of LOW concentration to HIGH concentration (against a concentration gradient) with the aid of a transport protein
-requires the input of energy (ATP hydrolysis)
99
isotonic
solute concentrations on both sides of membrane are equal
100
hypertonic
solute concentration is higher on this side of membrane compared to other side
101
hypotonic
solute concentration on this side of membrane is lower than other side
102
osmosis
water diffuses acress membrane from hypotonic compartment to hypertonic compartment
-when solutes cant readily move across membrane
103
primary active transport
type of transport that directly uses energy to transport solute against a gradient
104
secondary active transport
use of a pre-existing gradient to drive the active transport of another solute
-Na+/K+ pump (Na+/K+ ATPase)
105
exocytosis
material inside cell is packaged into vesicles and excreted into extracellular environment
-for transport of very large molecules (proteins, polysaccharides)
106
endocytosis
plasma membrane invaginates to form a vesicle that brings substances into cell
-for very large molecules (proteins, polysaccharides)
107
enzyme
proteins that act as critical catalysts to speed up different reactions in cells
-creat or breakdown reactions
108
metabolism
sum total of all chemical reactions that occur within an organism
- most create or breakdown molecules
- cells use intermediate molecules (ATP) to drive chemical reactions in a desired direction
109
energy
ability to producy change or do work
110
1st law of thermodynamics
energy cannot be created or destroyed
-can be transferred from one place to another or transferred between types of energy (i.e. chemical energy transferred to heat)
111
2nd law of thermodynamics
transfer of energy or transformation of energy from one form to another increases the entropy (degree of disorder) of a system
112
free energy
amount of available energy that can be used to promote change or do work
113
exergonic reaction
free energy is released during product formation
| -spontaneous reaction
114
endergonic reaction
required addition of free energy
| -NOT a spontaneous reaction (forms reactants)
115
hydrolysis of ATP
energy liberated is used to drive a variety of cellular processes
-ATP with addition of water breaks down to ADP + Pi (inorganic phosphate)
116
activation energy
initial input of energy to get molecules close enough to interact
- enzymes lower activation energy
- positions molecules closer together
117
enzyme inhibitors
bind to enzyme and inhibit their functions
118
competitive inhibitor
enzyme inhibitor that binds directly to active site so substrate can't find it
119
noncompetitive inhibitor
enzyme inhibitor that binds noncovalently to an enzyme at a location outside the active site (an allosteric site) and inhibits the enzymes function
120
metabolic pathway
coordinated sequences of reactions
| -each step catalyzed by a specific enzyme
121
catabolic reaction
breaks down molecules
- usually exergonic
- recycle organic building blocks and produce energy intermediates (ATP, NADH)
- can then use building blocks and energy intermediates to make new macromolecules
122
anabolic reaction
builds molecules
| -usually endergonic and must be coupled to an exergonic reaction
123
glycolosis
breakdown of glucose to pyruvate
- catabolic reaction
- creates ATP
124
oxidation
removal of 1+ electrons from atom/molecule (oxygen frequently involved/receiving electron)
125
reduction
```
adds electron(s) to atom/molecule
-reduces charge
```
126
redox reaction
one side is oxidized, other side is reduced
- electrons often go to NAD+ to make NADH
- NADH can be used to make ATP
- NADH also gives electrons to help anabolic reactions
127
cellular respiration
metabolic reactions that a cell uses to get energy from food molecules and release waste products
-makes ATP
128
aerobic respiration
uses oxygen to make ATP and releases CO2
- carbs, proteins, fats can be used as energy sources to drive respiration (glucose)
- glucose + 6O2 -> 6CO2 + 6H2O + energy intermediates (ATP) + heat
129
What are the pathway steps of aerobic respiration?
- glycolysis (glucose broken down into pyruvate, makes ATP)
- breakdown of pyruvate to an acetyl group in mitochondria (makes NADH)
- citric acid cycle in mitochondria (each acetyl group is incorporated into an organic molecule which is later oxidized to release CO2 (makes ATP, NADH, FADH2)
- oxidative phosphorylation (oxidation of NADH and FADH2 via electron transport chain provides more energy to make ATP, O2 is consumed, makes a lot of ATP. O2 is the final step of the electron transport chain to receive an electron, H2O is produced. At the end of electron transport chain, ATP synthase helps synthesizes ATP via oxidative phosphorylation)
130
anaerobic respiration
creates energy in the absence of sufficient oxygen (i.e. strenuous exercise). Has 2 different strategies:
- use a substance other than O2 as final electron acceptor in electron transport chain
- produce ATP only via substrate-level phosphorylation (an enzyme directly transfers a phosphate from an organic molecule to ADP)
131
How can glycolysis occur without O2
pyruvate from glycolysis is reduced to make lactate
- no net oxidation
- called fermentation
- yields WAY less ATP (2 vs ~30 during aerobic respiration)
132
direct intercellular signalling
- direct contact between cells
| - junctions enable them to pass ions, signaling molecules, etc. to one another
133
contact dependent cell signaling
-membrane-bound signaling receptors allow molecules to be in contact with both cells
134
autocrine cell signaling
- cell secretes signaling molecules that bind to receptors on its own cell surface, stimulating a response
- can affect nearby cells of same cell type
135
paracrine cell signaling
cell secretes signals that affect nearby target cells (but not itself)
136
endocrine cell signaling
secretion of hormones into bloodstream that travel up to long distances to target cells
-longer lasting signaling
137
What are the steps of cell signaling response?
- receptor activation (signaling molecule binds to receptor, causing confirmational change that activates its function)
- signal transduction (activated receptor stimulates a series of proteins that forms a signal transduction pathways
- cellular response (signal transduction pathway affects the functions and/or amount of cellular proteins, thereby producing a cellular response)
138
transcription factors
proteins that regulate the transcription of genes
| -ex: sex hormones do this
139
ligand
cell signaling molecule
| -binds noncovalently to cell receptor with high specificity
140
enzyme-linked cell receptor
extracellular dowmain binds to signal (ligand), intracellular domain has a cataclytic function activated
141
G-protein-coupled cell receptor
when bound to signal (ligand), interacts with intracellular G proteins
- causes G protein to bind with GTP instead of GDP
- G protein dissociates into alpha and beta, which causes response
142
ligand-gated ion channel
ligand binds to receptor to open channel and allow flow of ions through membrane
143
intracellular receptor
located inside cell
- many steroid hormone receptors are intracellular
- hydrophobic hormones can pass through plasma membrane
- steroid hormones bind receptors in nucleus
144
What are the roles of extracellular matrix?
- strength
- structural support (bones)
- organization (propoer arrangement of cells, binds body parts)
- cell signaling
145
cell junctions
specials structures that link cells
- anchoring junctions (attach cells to each other and to the ECM)
- tight junctions (forms tight seal between cells to prevent material from leaking between cells)
- gap junctions (small gap occurs between the plasma membranes of cells connected by these junctions
146
tissue
group of cells having a similar structure and function
147
What are the 4 types of animal tissues?
- epithelial
- connective
- nervous
- muscle
148
deoxyribonucleic acid
genetic material that provides the blueprint to produce an individuals traits
149
What are the components of nucleotides?
- phosphate group
- pentose sugar (deoxyribose in DNA)
- nitrogenous bases (A, G, T, C, U) that store and transmit info
150
DNA helicase
enzyme that uses ATP to unwind strands of DNA
| -travels along one strand
151
DNA topoisomerase
travels ahead of replication fork and removes foiling in DNA
151
DNA topoisomerase
travels ahead of replication fork and removes foiling in DNA
152
single-strand binding proteins
coat separated DNA strands to prevent the reforming of the double-helix until synthesis of complementary strands is complete
153
DNA polymerase
covalently links nucleotides together to form DNA strands in DNA replication
154
DNA primase
primes lone template DNA for DNA polymerase to work during DNA replication
155
DNA ligase
catalyzes formation of a covalent bond between DNA fragment during DNA replication
156
DNA proofreading
DNA can detect a mismatch and remove it from the daughter strand during DNA replication
157
telomere
short nucleutide sequence at the end of chromosome that is repeated many times
- because DNA polymerase cannot copy end of DNA strand
- telomerase attaches telomeres together
158
transcription
produces an RNA copy of a gene
- messanger RNA carries info from DNA to ribosome
- contains info to make a polypeptide with a specific amino acid sequence
159
translation
synthesizes a specific polypeptide on a ribosome
-mRNA is translated into amino acid sequence
code is read in groups of 3 nucleotide bases known as codons (that specify an amino acid)
160
transfer RNA (tRNA)
translates the language of mRNA into that of amino acid during translation (has amino acid attached to it)
161
ribosomal RNA (rRNA)
forms part of ribosomes
162
promotor
signals the beginning of transcription of DNA
163
terminator
signals the end of transcription of DNA
164
regulatory sequence
when regulatory proteins bind to this, it affects the rate of transcription
165
RNA polymerase
runs along DNA and synthesizes RNA from the promoter to the terminator during transcription
166
transcription factors
proteins that influence the ability of RNA polymerase to transcribe genes
- required to initiate transcription
- steroid hormones can act as transcription factors
167
ribosome
site where translation occurs
| -usually in cytosol, but some ribosomes are in the mitochondria as well
168
What is gene expression?
process by which info within a gene is made into a functional product
169
What is gene regulation?
the ability of cells to control the expression of genes
- timing, amount
- conserves energy
- produce proteins only when needed
170
diploid
2 sets of chromosomes
- most eukaryotic cells
- homologous pairs (1 from mom, 1 from dad)
171
haploid
1 set of chromosomes
| -gametes are haploid
172
What is the cell cycle?
sequence of growth, replication, and division that produces new cells
173
Describe the phases of mitosis
- interphase - cell growth
- interphas - chromosomes (DNA) replicated (after replication, the 2 copies are still joined to each other as a pair of sister chromatids)
- interphase - cell synthesizes proteins needed for chromosome sorting and cell division
- prophase - nuclear envelope begins to dissociate into small vesicles and chromatids condense into highly compacted structures
- prometaphase - nuclear envelope completely fragments into small vesicles and mitotic spindle is formed (cnetrosomes move to the 2 poles)
- metaphase - pairs of sister chromatids align along the metaphase plate
- anaphase - sister chromatids separate and chromosomes more toward poles
- telophase - chromosomes reach respective poles and decondense, nuclear envelope reforms to produce 2 nuclei
- cytokinesis - cleavage furrow separates mother cell into 2 daughter cells
174
zygote
fertilized egg, diploid
| -grows and divides by mitosis
175
meisosis
haploid cells are produced from a cell that was originally diploid
- 1 chromosome from each of the pairs
- single diploid cell with homologous pairs of chromosomes produces 4 haploid cells
- diploid cells in testes and ovaries undergo meiosis to produce haploid sperm and eggs
176
Describe the phases of meiosis
- interphase -cell growth
- interphase - chromosomes (DNA) replicated (after replication, the 2 copies are still joined to each other as a pair of sister chromatids)
- interphase - cell synthesizes proteins needed for chromosome sorting and cell division
- meiosis 1 - separates homologues from each other
- meiosis 1 prophase 1 - replicated chromosomes condense, homologous chromosomes form bivalents and crossing over occurs. Nuclear envelope starts to fragment into small vesicles
- meiosis 1 prometaphase 1 - nuclear envelope completely dissociates into vesicles. Bivalents become attached to kinetochore microtubules
- meiosis 1 metaphase 1 - bivalents randomly align along the metaphase plate
- meiosis 1 anaphase 1 - homologous chromosomes separate and move toward opposite poles by kinetochore microtubules
- meiosis 1 telophase 1 - chromosomes decondense and nuclear envelope reforms
- meiosis 1 cytokinesis - separates 2 haploid daughter cells
- meiosis 2 - analogous to mitotic division
177
Mendel's Law of Segregation
two alleles of a gene separate during gamete formation so that every gamete receives only one allele
-during segregation of homologous chromosomes during meiosis
178
homozygous
2 identical alleles for a gene
179
heterozygous
2 different alleles for a gene
180
phenotype
characteristics of an organism that are the result of the expression of its genes
181
monohybrid cross
follows 1 trait/variant across generations
182
dihybrid cross
simultaneously follows the inheritance of 2 different traits
183
Law of Independent Assortment
alleles of different genes assort independently of each other during gamete formation
- independent alignment of different chromosomes during meiosis
- not the case for ALL alleles (alleles near each other on same chromosomes are less independent)
184
Chromosome Theory of Inheritance
inheritance patterns of traits can be explained by the transmission of chromosomes during meiosis and fertilization
185
locus
physical location of a gene on a chromosome
186
pedigree analysis
an inherited trait is analyzed over the course of a few generations in one family
187
Mendelian Inheritance
inheritance pattern of genes that segregate and assort independently
188
Explain the dominant vs. recessive allele
recessive allel is often defective in its ability to express a function protein while the dominant allele makes enough the the protein to give the dominant phenotype
189
norm of reaction
effects of environmental variation on a phenotype
190
gene interaction
all or nearly all traits are influenced by many genes, each of which have 2+ alleles
191
epistasis
allele of one gene masks the phenotypic effects of a different gene
-2 or more proteins involved in a singular cellular function
192
genetic imprinting
a segment of DNA is imprinted or marked so that gene expression occurs only from the genetic material inherited from 1 parent
193
developmental genetics
understanding how gene expression controls the process of development
194
cell differentiation
cells morphology and function change into a highly specialized cell type
195
pattern formation
development of a body plan
- cell division
- cell migration
- cell differentiation
- cell death
196
morphogens
impart positional information and promote developmental changes at the cellular level
197
Describe the phases of development in animals.
- transcription factors determine formation of the body axes and control the expression of transcription factors of next phase
- transcription factors cause the embryo to become subdivided into regions that have properties of individual segments. Control transcription factors of next phase
- transcription factors cause each segment and groups of segments to develop specific characteristics. Control transcription factors of next phase
- transcription factors cause cells to differentiate into specific cell types such as skin, nerve, muscle cells (differential gene expression)
198
differential gene expression
different types of cells have same genes but activate/deactivate them differently
199
When was the big bang?
Approximately 13.7 billion years ago
200
When did the Earth form?
Approximately 4.6 billion years ago
201
When did like on Earth begin?
Approximatley 3.5-4 billion years ago
202
Describe the origin of life on Earth
- nucleotides and amino acids were produced prior to the existence of cells ("primordial soup")
- nucleotides became polymerized to form RNA and/or DNA and amino acids became polymerized to form proteins
- RNA/DNA and proteins became enclosed in membranes
- polymers enclosed in membranes acquired cellular properties
- Believe RNA came before DNA
203
When were the first multicellular eukaryotic organisms formed?
Approximately 1.5 billion years ago
204
Cambrian explosion
explosion of animal diversity
| -possibly due to an increase in oxygen in the atmosphere allowing aerobic metabolism
205
evolution
heritable change in one or more characteristics of a population from one generation to the next
206
microevolution
change in gene or allele frequency
207
macroevolution
formation of a new species or groups of related species
208
molecular evolution
molecular changes in the genetic material that underly the phenotypic changes associated with evolution
209
What causes evolution to occur?
- genetic variation (pass down from random mutations in genes)
- natural selection (individuals with heritable traits that make them better suited to their environment tend to flourish and reproduce, other individuals less likely to survive and reproduce)
210
biogeography
study of geographic distribution of extinct and living species
-isolated islands and continents have evolved their own distinct plant and animal communities
211
convergent evolution
two different species from different lineages have independently evolved similar characteristics because they occupy similar environments
212
analogous structure
characteristics that originated independently but are similar
213
homology
similarity that occurs due to descent from a common ancestor
- anatomical (forearms for walking, flying, swimming)
- developmental (ways animals undergo embryonic development)
- molecular (DNA, RNA)
214
gene pool
all the elleles for every gene in a population
215
Hardy-Weinberg Equation
described the relationship between allele and genotype frequencies when a population is NOT evolving
(p)^2+2pq+(q)^2=1
216
directional selection
favors an extreme end of a phenotype
217
stabilizing selection
favors intermediate phenotypes
218
diversifying selection
favors survival of 2 different phenotypes
| -patchy environment
219
balancing selection
maintains genetic diversity
220
sexual selection
traits that make it more likely to find or choose a mate and mate successfully directly promotes reproductive success
221
intrasexual selection
traits that help competition with other males
| -big claws to fend off other males for crabs
222
intersexual selection
traits that help female pick male
| -flashy mating behavior
223
genetic drift
changes in allele frequency due to random chance (can be beneficial or bad) regardless of fitness
-greater impact at small population size
224
bottleneck effect
dramatic event reduces population size with different alleles or genetic drift decreases genetic variation more quickly
225
founder effect
when small group separates from population and establishes colony in a new location
-allele frequency may be different from old population
226
inbreeding depression
breeding with related mates generally decreases reproduction success of population
227
speciation
formation of new species typically through the accumulation of microevolutionary changes (mutations in genes)
228
What are prezygotic mechanisms of reproductive isolation?
- habitat isolation
- temporal isolation (breed at different times)
- behavioral isolation (different mating behavior or anatomy)
- mechanical isolation (incompatible size or genetalia
- gametic isolation (gamete fails to unite in a successful fertilizing event)
229
What are postzygotic mechanisms of reproductive isolation?
block development after fertilization
- hybrid inviability (fertilized egg can't develop past early embryonic stages)
- hybrid sterility (offspring lives but is sterile. ex: mule)
- hybrid breakdown (hybrid is viable and fertile but subsequent generations may have genetic abnormalities that are detrimental)
230
What are the 2 mechanisms of speciation?
- allopatric speciation
| - sympatric speciation
231
allopatric speciation
some members of a species occupy and isolated habitat (geographic barrier) that causes new species
232
sympatric speciation
members of a species diverge into different species even though they are in the same range and there are no barriers to inbreeding
- polyploidy (organism has more than 2 sets of chromosomes. plants)
- adaptation to local environment (variation in environment that does not have barriers)
- sexual selection (mate choice)
233
evolutionary developmental biology
compares the development of different organisms in an attempt to understand ancestral relationships between organisms and the developmental mechanisms that bring about evolutionary change
234
phylogeny
evolutionary history of a species or group of species
235
anagenesis
a single species evolves into a new species
236
cladogenesis
a species diverges into 2 ore more species
237
clade
common ancestral species and all of its descendent species
238
What are the common characteristics of animals?
- multicellularity
- heterotrophs
- no cell walls
- nervous tissue
- muscles/movement
- sexual reproduction
- extracellular matrix
- characteristic cell junctions to hold cells in place and allow cell communication
- species clusters of Hox genes (function in patterning the body axis) cause variation in morphology
- similar RNA
239
What are the 4 features of body plans that traditional animal classification is based on?
- presence/absence of different tissue types
- type of body symmetry (radial vs bilateral)
- presence/absence of a true body cavity
- specific features of embryonic development (cleavage, mouth/anus)
240
What are some other features of animal classification outside the traditional 4 features?
- presence of exoskeleton
- development of notochord
- presence of segmentation
241
What are the features of the Phylum Chordata?
- notochord (becomes spine in humans)
- dorsal hollow nerve cord (becomes nervous system in humans)
- pharyngeal slits
- postanal tail
242
umbrella species
a species that requires large home range
| -ensures conservation of many other species
243
What are the characteristics of the Subphylum Craniata in the Phylum Chordata?
- cranium - protective enclosing for a more developed brain
- neural crest - group of embryonic cell found on either side of the neural tube as it develops (these cells disperse throughout the embryo and contribute to the skeleton (cranium, jaws, teeth))
244
What are the characteristics of Vertebrates?
- vertebral column replaces notochord during development
- endoskeleton of cartilage or bone
- diversity of internal organs
245
What are the characteristics of Chondrichythes?
- cartilaginous skeleton
- serial tooth replacement
- dermal denticles
- 2-chambered heart
- lateral line (senses movement)
- internal fertilization
246
What are the characteristics of bony fishes?
- bony skeleton
- operculum covers gills
- swim bladder
- most have external fertilization
247
What are the types of animal tissue?
- muscle (body movement)
- nervous (conduct electrical signals throughout body)
- epithelial (cover body and line walls of organs)
- connective (support structures)
248
homeostasis
process of maintaining a relatively stable internal environment despite changes in external surroundings
249
What factors are involved in regulating internal environment vs. conforming?
- requires energy (ATP)
- requires communication between cells (neurotransmitters for local communication and hormones for long distance communication)
250
nervous system
coordinated curcuits of cells (neurons) that sense internal and environmental changes and transmit signals that enable us to respond in an appropriate way
251
neurons
highly specialized cells that communicate with each other and other types of cells by electrical or chemical signals
252
nerves
bundles of neuronal cell extensions projecting to and from various tissues and organs
253
central nervous system
brain and nerve cord (spinal cord in vertebrates)
254
peripheral nervous system
neurons outside the central nervous system
255
neuron cell body or soma
contains cell nucleus and organelles, processes signals
256
neuron dendrites
projections of plasma membrane that receives signals
257
neuron axons
projections of plasma membrane that sends signals
258
glia
surround neurons
- metabolic support for neurons
- maintain ion concentration in extracellular fluid
- remove cellular debris
259
What are the 3 types of neurons
- sensory neurons (sense info and transmit it to CNS)
- motor neurons (send signals away from CNS and elicit response such as movement)
- interneurons (form interconnections between neurons in CNS)
260
How do neurons work?
- establish differences in ion concentration and electrical charge across their membranes
- an electrochemical gradient governs movement of ions across membrane
- signaling by a neuron occurs through changes in membrane potential
261
neuron synapse
a junction where an axon terminal meets a target neuron, muscle cell, or gland in order to communicate with these cells
262
nerve net
- simplest nervous system (found in cnidarians)
| - no single group of neurons controls all the others (like the brain)
263
nerve cord
- extend from anterior to posterior
- connect to each other by transverse nerves
- cerebral ganglia
264
cephalization
formation of complex brain that controls sensory and motor functions of entire body
-usually has more than 1 anatomical and functional region
265
hindbrain
- basic reflexes and bodily functions, movements
| - medulla oblongata, pons, cerebellum
266
midbrain
- processes many sensory inputs
| - vision, olfaction, auditory
267
forebrain
initiates motor functions and processes sensory inputs, conscious thought, planning, emotions
- cerebrum and cerbral cortex (thought, learning, movement)
- thalamus, hypothalamus, epithalamus
268
ganglion
group of neuronal cell bodies located in the peripheral nervous system
269
somatic nervous system
sense external environment and controls skeletal muscles
270
autonomic nervous system
regulates homeostasis and organ function
- involuntary
- sympathetic and parasympathetic nervous system
271
sympathetic nervous system
rapidly activating systems that prepare the body for danger or stress
272
parasympathetic nervous system
maintaining and restoring body functions
273
medulla oblongata
coordinated basic reflexes and bodily functions that maintain homeostasis
274
cerebellum
receives sensory inputs
| -balance, hand-eye coordination
275
thalamus
relay sensory info to appropriate parts of the cerebrum
276
hypothalamus
controls functions of gastrointestinal and reproductive systems, thermoregulation, basic behaviors (eating, drinking)
- produce hormones
- circadian thythm
277
pineal gland
- rhythmic/seasonal behaviors (melatonin)
| - drinking, eating
278
cerebrum
planning, learning, fine-tuning movement
279
amygdala
emotions
280
hippocampus
memories
281
sensory receptor
recognizes an internal or external stimulus and initiates sensory transduction by creating graded potentials in itself or adjacent cells
282
lateral line
hair cells inside pores detect changes in water current associated with external movements
283
nocireceptors
sense pain
| -respond to tissue damage or stimuli about to cause tissue damage
284
tapetum lucidium
behind retina that reflects light back to photoreceptors to help see in dark
285
muscles
composed of highly specialed cells that contract in response to stimuli
- shortening of muscles causes movement
- muscle contraction requires ATP and calcium ions
- calcium binds to troponin, which allows tropomyosin to move and uncover the actin binding site
- contraction is coupled with electrical excitation
286
oxidative muscle fibers
- red muscle
| - lots of mitochondria, blood vessels, myoglobin, O2
287
glycolytic muscle fibers
- white muscle
- few mitochondria, blood vessels, O2, myoglobin
- high concentration of glycogen to do glycolysis
288
metabolic rate
rate at which an organism uses energy to power reactions
| -generates heat as byproduct
289
glycogenolysis
glycogen broken down to glucose via hydrolysis
290
gluconeogenesis
creation of new glucose using fat stores or proteins
291
arteries
pump blood from heart to rest of body
292
veins
pump blood from body to heart
293
vasodilation
increase in blood vessel radius
- increases blood flow
- better for O2 and nutrient delivery
294
vasoconstriction
decrease in blood vessel radius
| -decreases blood flow
295
How much of standard MR is used for ventilating gills?
10-20%
296
Explain osmoregulation in marine fish
- hypoosmotic to environment
- water moves out, salts move in
- drink constantly
- secrete very little concentrated urine
- active transport of Na+ Cl- out of gills
297
How are excess salts eliminated in sharks?
- kidney and rectal gland
| - keep high concenration of urea and TMAO
298
stenohaline
tolerate narrow salt range
299
euryhaline
tolerate wide salinity range
300
antidiuretic hormone (ADH)
helps with water reabsorption in kidney
301
hormone
chemical which circulates throughout body via bloodstream to target tissues to affect a range of functions
302
amine hormones
- derived from amino acids
- must bind to plasma membrane receptor
- hydrophilic
- catecholamines, dopamine, melatonin
303
peptide hormones
- water soluble
- must bind to plasma membrane receptor
- insulin, glucagon, leptin
304
steroid hormones
- from cholesterol, lipids
- hydrophobic
- bound to carriers in blood
- can diffuse across plasma membranes
- bind to intracellular receptors (in cytosol or nucleus)
- function as transcription factors
305
hypothalamus hormone involved in reproduction
gonadotripin releasing hormone
306
anterior pituitary hormones related to reproduction
- follicle stimulating hormone
| - leutinizing hormone
307
gametogenesis
formation of gametes
- primordial germ cells multiply by mitosis resulting in diploid cells (spermatogonia and oogonia)
- some become primary spermatocytes or oocyes and begin meiosis
308
spermatogenesis
formation of haploid sperm from original diploid germ cell
309
acrosome (of sperm)
structure at tipe of head of sperm with enzymes that break down protective outer layer of ovum
310
oogenesis
results in production of a single gamete from each primary oocyte
311
leydig cells
make testosterone (not really in sharks)
312
sertoli cells
aid in spermatogenesis, make T in sharks
313
epididymis
long tube where sperm complete differentiation
314
seminal vesicles
secretes fructose in semen that are nutrients for sperm
315
population ecology
understand the factors that affects a population growth and determine its size and density
316
community ecology
how populations of species interact and form functional communities
317
ecosystem
- flow of energy and cycling of chemical elements among organisms and between organisms and the environment
- food weds
318
proximate causes
specific genetic or physical mechanisms of behavior
319
ultimate causes
effect of behavior on survival or reproductive success
320
kinesis
movement in response to a stimulus but one that is not directed toward or away from the source
321
taxis
more directed movement response either toward or away from an external stimulus
322
optimality theory of foraging
optimize benefits vs costs of remaining at a resource patch to look for more food or looking for a completely new patch of resources
323
population
group of interbreeding individuals occupying the same area at the same time
324
demography
study of birth rates, death rates, age distribution, sizes of populations
325
semelparous
reproduce once in lifetime
326
iteroparous
reproduce throughout lifetime
327
bet hedging
reproduction throughout life is used when survivial of juveniles is poor or unpredictable
328
Why do we plot survivorship curves on a log scale
to examine rates of change over time rather than change in absolute numbers
-allows easy comparison between species
329
exponential growth
rN
- resources are not limiting (no carrying capacity)
- can occur in new, expanding population
330
logistic growth
rN((K-N)/K)
| -resources are limiting (carrying capacity)
331
amensalism
one individual is harmed, other not affected
332
mutualism
both species benefit
333
commensalism
one species benefits, other not effected
334
exploitation competition
compete indirectly through consumption of limited resources
335
interference competition
direct, physical/intimidation competition
336
competitive exclusion principle
2 species cannot occupy same niche in same space
337
resource partitioning
differentiation of niches that enable similar species to coexist in a community
338
character displacement
tendency for 2 species to diverse in morphology and resource use because of competition
-darwins finches
339
bottom-up model
food limitation influences population density
340
top-down model
predator controls prey population
341
species-area hypothesis
larger areas support more species
342
intermediate disturbance hypothesis
moderately disturbed communities contain more species
343
species diversity
incorporates number of species and relative abundance of each species
344
diversity stability hypothesis
species rich communities are more stable than those with fewer species
-more likely to contain disturbance-resistant species
345
succession
gradual and continuous change in species composition and community structure over time
346
autotroph
harvest light or chemical energy and store energy in carbon compounds
347
heterotrophs
receive nutrients by eating organisms
348
decomposers/detritivores
break down dead organisms
349
production efficiency
percentage of energy assimilated by an organism that becomes incorporated into new biomass
350
trophic-level transfer efficiency
amount of energy acquired by higher trophic level and incorporated into biomass
-always lose some energy (via heat) between trophic levels
351
net primary production
gross primary production - cellular respiration
| -amount of energy available for consumers
352
biodiversity
genetic diversity of species, the variety of species, and the different ecosystems they form
353
conservation biology
uses principles of molecular biology, genetics, and ecology to protect biodiversity at each different level
354
Why conserve biodiversity?
- food, medicine
- ecosystem services
- ethics
- reduced biodiversity leads to reduced ecosystem functioning
355
introduced species
moved to non-native area
356
invasive species
introduced species that outcompetes native species
357
phenology
timing of life events
358
inbreeding
mating of genetically related relatives
| -causes reduced fitness and survival
359
Allee effect
decline in reproduction and survival in small populations
- harder to find mate
- reduced genetic diversity
360
SLOSS debate?
single large or several small reserves
361
flagship species
large, charismatic species with public support
362
keystone species
large ecological role in proportion to abundance/biomass
