Biological Principles Final Exam Prep

Mutation always causes:

New genetic variation

What stratigraphic principle allows scientists to determine that the lowest (furthest to the bottom) layer in an undisturbed rock sequence is the oldest?

Principle of Superposition

The half-life of carbon-14 is about 6,000 years. You find a fossilized bone and discover that it has 1/4 of the  proportion of today’s level of carbon-14 to carbon-12 . Approximately how old is your discovered fossil? 

12,000 years

In the equation p² + 2pq + q² = 1, what does p² represent? 

The frequency of one of the homozygous genotypes in a population

Which of the following is the reason RNA is thought to be the first genetic material according to the RNA world hypothesis?

RNA can both store genetic material and catalyze reactions

Below is a phylogenetic tree depicting the evolution of thumbs in pandas and primates. Thumbs be considered an example of [ Select ] ["analogous", "homologous"] structures because [ Select ] ["because both groups inherited thumbs from a common ancestor", "because thumbs evolved independently in the different groups", "because pandas and primates are more closely related than rodents", "none of these"] ? 

analogous, because thumbs evolved independently in the different groups

Cyanobacteria led to [ Select ] ["biological oxygen production", "formation of the chloroplast", "formation of the mitochondria", "the first RNA genome"] in early Earth’s atmosphere and [ Select ] ["this gave rise to plant cells and other photosynthesizer cells", "this led to the hereditary mechanism for future life", "this allowed for adaptive radiation of eukaryotes", "this led to the mass extinction event of all non-avian dinosaurs"] . 

biological oxygen production, this allowed for adaptive radiation of eukaryotes

Which of the following is NOT a requirement for living things?

Cells with membrane-bound organelles

A volcanic eruption wipes out most of a population of lizards, leaving only a few survivors. Over several generations, the population rebounds, and the new population of lizards has shorter tails on average than the original population. What evolutionary process is the most likely explanation for this change in average tail length? 

Genetic drift

Any trait that _______ _________ is likely to promote speciation between two populations.

prevents gene flow

[ Select ] ["None of these", "1", "3", "2", "4"] represents the most recent common ancestor of A and D. From this tree, I can conclude [ Select ] ["D is the most ancient taxa", "None of these", "B and C are more closely related to D than they are to A", "B and C are the most recent taxa compared to A and D", "A is more distantly related to D than it is to B and C"] .

2, A is more distantly related to D than it is to B and C

Which of the following is likely to decrease the amount of genetic diversity in a population? 

1. Gene flow

2. Genetic drift

3. Natural selection 

2 and 3

Suppose that a population of grasshoppers migrates from an area with few birds to an area with many birds. Birds are predators to grasshoppers. In this new environment, the largest grasshoppers are more likely to be eaten by birds than the smaller and medium-sized grasshoppers. After one generation in the new environment, the grasshoppers are now smaller on average than they were in the original population. As a result, this population of grasshoppers:

All of these

Which of the following is true about this phylogenetic tree?

Species S is equally related to species X and species A.

Two populations would be considered different species under the ecological species concept if they have:

1. Visually distinguishable morphologies

2. Habitat-cause reproductive isolation

3. An inability to produce fertile offspring

4. Ranges that never overlap 

2

The strong inference approach differs from what is typically considered the “standard” scientific method in which of the following ways? 

Strong inference tries to prove a hypothesis wrong

What are the three domains of life? 

Bacteria, Archaea, Eukarya

Unlike a scientific hypothesis, a scientific theory: 

Includes multiple, independent lines of evidence

Based on the principle of parsimony, which of the following is likely FALSE of the last universal common ancestor (LUCA)?

It had an RNA genome

Two populations of frogs co-exist in the same marsh. Males of population A attract potential mates with a slow, deep croaking pitch. Males of population B attract potential mates with a faster, higher croaking pitch. Females of population A are more likely to mate with males of population A, and females of population B are more likely to mate with males of population B, but when individuals from different populations mate, they are able to produce fertile offspring. These populations may be experiencing [ Select ] ["biological", "sympatric", "allopatric"] speciation, and the barrier to reproduction between these populations is [ Select ] ["gametic", "mechanical", "temporal", "behavioral", "habitat"] which is a [ Select ] ["anti-zygotic", "post-zygotic", "pro-zygotic", "pre-zygotic"] barrier.

sympatric, behavioral, pre-zygotic

The graph shows the density of algae grown in media containing different concentrations of phosphorus over several days in the lab. Which option best describes the role of the No phosphorus condition in this experiment? 

A negative control

Acting on its own, which of the following has the least effect on the evolution of a population?

Mutation

Two populations of frogs co-exist in the same marsh. Males of population A attract potential mates with a slow, deep croaking pitch. Males of population B attract potential mates with a faster, higher croaking pitch. Females of population A are more likely to mate with males of population A, and females of population B are more likely to mate with males of population B, but when individuals from different populations mate, they are able to produce fertile offspring. The hybrid males have an intermediate croaking pitch and are less successful in attracting mates than non-hybrid individuals. Which of the following is likely to occur? 

The populations will experience increased selection for pre-zygotic barriers

Which of the following is NOT part of the Oparin-Haldane hypothesis? 

Cyanobacteria were the first life forms to produce oxygen in photosynthesis

Over several generations, the average wing color of a butterfly population has shifted significantly. If this change is the result of natural selection, which of the following explains why the new phenotype is increasingly represented in the population? 

The butterflies with the new phenotype produce more successful offspring than other butterflies

Anole lizards are small green lizards that live throughout the southeastern United States. They are eaten by a wide variety of predators, including birds, snakes, and larger lizards. The length of the anole’s legs influences how well it can escape from different types of predators, with longer legs allowing better escape from some predators, and short legs allowing better escape from other predators. Over the course of multiple generations of anoles, a study observed that average leg lengths of the anole lizard varied from year to year without a consistent pattern: some years there were more shorter-legged lizards, and other years there more longer-legged lizards. Leg length in anole lizards is experiencing:

Balancing selection

Which of these is the most accurate definition of evolution? 

The change in the frequency of genetic variants within a population over time

The graph shows the density of algae grown in media containing different concentrations of phosphorus over several days in the lab. What is the independent variable in this experiment?

Amount of phosphorus

Mathematically, you tell if a population is in HWE when:

the genotype frequencies that are observed in the population are p^2, 2pq, and q^2

Which of the following is the best definition for fitness? 

The number of successful offspring an individual produces compared to others in the population

Which of the following is NOT one of the key assumptions for a population to be considered in Hardy-Weinberg Equilibrium?

There is only random mating

Which of the following statements about the Cambrian Radiation is/are correct?

1. All of the major animal groups we know of first appeared in the fossil record in the early Cambrian.

2. Most of the lineages that first appeared in the early Cambrian have gone extinct.

3. Atmospheric oxygen concentrations declined in the early Cambrian, reducing the overall toxicity of the atmosphere and allowing the evolution of large, multicellular organisms.

Statement I is correct

A population of frogs has a trait that is controlled by two alleles, R and r. You are studying a population composed of 100 individuals with the RR genotype, 200 individuals with the Rr genotype, and 700 individuals with the rr genotype. In this population, the predicted genotypic frequency of individuals with the Rr genotype is ____ , and the population _____  assuming a 3% margin of error. 

0.32, is evolving

Which of the red boxes indicates a monophyletic group? 

A, B, and C

Which of the following pieces of data would NOT be used to construct a phylogenetic tree?

Analogous traits that evolved independently in time

Which of the following can be used to distinguish a eukaryotic cell from a prokaryotic cell? 

Presence of an ER

The activity of PEP carboxylase in C4 plants: 

None of these

You identify a new single-celled species and determine that its plasma membrane contains many ether-linked isoprenoid chains. You are confident that this species should be classified within domain: 

Archaea

You discover a new species of bacteria that appears to be photosynthetic. You determine that it is able to use light energy to produce ATP and to reduce an electron carrier, and it does not produce oxygen gas. You conclude that the bacterium posesses: 

Photosystem I only

What is the location of translation for an enzyme that resides in the Golgi? 

Rough ER

Place the components of the Z scheme in order from electron donor to terminal electron acceptor: 

Electron donor =

First location =

Second location =

Third location =

Terminal electron acceptor =

Options: Carbon dioxide, ETC, Glucose, NADP+, Oxygen, Photons, PSI, PSII, Water

Electron donor = Water

First location = PSII

Second location = ETC

Third location = PSI

Terminal electron acceptor = NADP+

If a eukaryotic cell has insufficient terminal electron acceptors available, it can regenerate __________ through __________ in order to perform __________.

NAD+, Fermentation, Glycolysis

Which of the following is NOT a mechanism that cells use to maintain cellular structure and order? 

Maintaining chemical equilibrium of their chemical reactions

Which chlorophyll molecule has the greatest amount of potential energy upon photon absorption? 

P680

When the photosystem of a cyanobacterium engages in cyclic electron flow: 

 An additional proton is pumped across the thylakoid membrane

Facilitated diffusion is defined as ___________ and is illustrated by _______ . 

Movement of a molecule down its concentration gradient through a channel across a membrane, A

The reaction shown is Exergonic , the overall change in free energy of the enzyme-catalyzed reaction is represented by letter [ Select ] ["e", "b", "d", "c", "a"] , and the overall change in free energy of the reaction without the enzyme is represented by letter [ Select ] ["b", "d", "e", "c", "a"] . 

Exergonic, d, d

 Fatty acids enter the metabolic pathways as an input to: 

Citric acid cycle

Which of the following was directly required for the evolution of the endomembrane system and mitochondria? 

Endocytosis

When [ Select ] ["NADH", "NAD+"] is not carrying an electron and then accepts an electron from an organic molecule, the carrier becomes [ Select ] ["Oxidized", "Reduced"]  and the organic molecule becomes [ Select ] ["Reduced", "Oxidized"] .

NAD+, Reduced, Oxidized

A difference between oxidative phosphorylation and photophosphorylation is: 

 Whether redox reactions or light is used as an energy source

Which of the following is a direct consequence of electrons moving all the way through the mitochondrial electron transport chain? 

1. Oxygen is converted to water

2. ATP is synthesized from ADP and Pi

3. Glucose is converted to carbon dioxide

4. Protons move across a membrane against their concentration gradient 

1 and 4

Carbon monoxide poisoning occurs because the hemoglobin in red blood cells, which transport oxygen to cells throughout the body, will preferentially bind to carbon monoxide over oxygen. As a result, tissues in the body become deprived of oxygen resulting in cell death. What is the effect on each of the following when oxygen is no longer available?

Electron flow through the mitochondrial ETC:

Proton gradient:

ATP production:

Decrease, Decrease, Decrease

When a cell engages in anaerobic respiration, it: 

1. Performs fermentation

2. Does not perform oxidative phosphorylation

3. Uses a terminal electron acceptor other than oxygen 

3

If a cell experienced a dramatic increase in temperature, it could maintain the same level of membrane fluidity by increasing production of:  

Saturated fatty acids and/or sterols

If all secretory vesicles became nonfunctional, where would newly synthesized proteins that are destined for the plasma membrane accumulate? 

Golgi apparatus

The majority of a plant’s biomass is composed of [ Select ] ["Molecules in the air", "Molecules in the soil", "Molecules from the sun", "Molecules in the water"] due to the plant’s ability to perform [ Select ] ["Photophosphorylation", "The Calvin cycle", "The citric acid cycle", "Oxidative phosphorylation"] . 

Molecules in the air, The Calvin cycle

If a plant is placed in a sealed environment with access to sunlight and without CO2, which of the following will occur in the Calvin cycle? 

X will accumulate, 3PG will become depleted

Match each biological macromolecule with its subunits:

Nucleic acids =

Proteins =

Glycans =

Lipids =

Options: Amino acids, Fatty acids, Glycerols, Isoprene chains, Nucleotides, Not applicable

Nucleic acids = Nucleotides

Proteins = Amino acids

Glycans = Monosaccharides

Lipids = Not applicable

An organism that gets energy from chemical reactions to synthesize ATP and reduces inorganic carbon is classified as a [ Select ] ["None of these", "Auto", "Photo", "Chemo"] [ Select ] ["Hetero", "Chemo", "None of these", "Auto", "Photo"] troph. 

Chemo, Auto

The molecule(s) in the list below that NEVER require a protein channel to cross a lipid membrane are those that are: 

Both nonpolar and small

Which of the following is an organic molecule? 

None of these are organic

The Calvin cycle requires which of the following products that are produced by the light-dependent reactions?

ATP and NADPH

Which of the following occurs within the mitochondrial matrix of both eukaryotes and prokaryotes?

None of these

The overall three-dimensional shape of a protein is its __________ , which is comprised of ____________ . 

Tertiary structure, Interactions among R groups and among the peptide backbone

When a cell is performing respiration, what is the series of metabolic pathways starting with glucose? 

Pathway 1 =

Pathway 2 =

Pathway 3 =

Pathway 4 =

Options = Calvin cycle, Electron transport chain, Fermentation, Glycolysis, Light-dependent reactions, Pyruvate oxidation, Pyruvate reduction, Substrate-level phosphorylation

Pathway 1 = Glycolysis

Pathway 2 = Pyruvate oxidation

Pathway 3 = Citric acid cycle

Pathway 4 = Electron transport chain

A particular hydrophobic amino acid is located within the transmembrane domain of a membrane channel protein, and this amino acid interacts with the lipid tails of the membrane. If this hydrophobic amino acid were changed to a positively charged amino acid, which of the following outcomes would be likely? 

The channel protein likely would no longer be able to integrate into the membrane and would no longer function

Which of the following best describes rubisco’s role in the Calvin cycle? 

Rubisco catalyzes a reaction adding CO2 to a 5-carbon RuBP acceptor molecule, producing two 3-carbon products

In the diagram below, the difference between the lower-case letter “b” and the lower-case letter “c” is best described as: 

The difference in free energy of the transition state with vs without an enzyme

The graph shows the kinetics of an enzyme-catalyzed reaction. Reaction A is the reaction without any potential modulator added. A small amount of molecule X has been added in reaction B, and a large amount of molecule X has been added in reaction C. Molecule X does not bind to the active site of the enzyme. In A, B, and C, the concentration of the enzyme is the same. Based on this information, Molecule X is a ________ that _________  of the enzyme. 

Allosteric inhibitor, Decreases Vmax

Which of the following statements is false about lagging strand synthesis in DNA replication?

 

DNA synthesis proceeds in the same direction as the replication fork is moving

Match each type of RNA to the role it plays in the “central dogma” of molecular biology:
mRNA =

rRNA =

tRNA =

mRNA = is copied from DNA and serves as a template for protein synthesis

rRNA = catalyzes the reaction join amino acids to the growing polypeptide chain

tRNA = carries amino acids to add to the growing polypeptide chain

When building a Punnett square to determine offspring types for an individual with the genotype DdEe, the gametes listed above each column would be:

DE, de, De, and dE

An individual who is homozygous recessive for a trait mates with an individual who is heterozygous for that trait. For simple mendelian inheritance, the expected genotypic and phenotypic ratios, respectively, are:

 

1:1 and 1:1

An mRNA for a functional protein begins with 5’-GCAUGCAUCGUA…-3’. Referring to the codon table, a possible amino acid sequence encoded is:

 

Met-His-Arg

If the image represents the entire chromosomal collection of a cell, what can you say about the cell? 

 

Haploid with unreplicated chromosomes

The sequence below is the template strand of gene. What is the mRNA transcribed from this sequence of the gene?

DNA template: 5’-ACGCATG-3’ 

 

 

5’-CAUGCGU-3’

An individual who has sickle-cell anemia and an individual who does not have sickle-cell anemia have a child. At birth, doctors took a blood sample from their child and found that it contained both normal and sickle red blood cells. What is the most obvious explanation for this pattern?

 

one gene with co-dominance

If genes assort independently, then ___________ or ___________ .

they are not linked but are on the same chromosome, they are not linked and are on different chromosomes

When a promoter element is bound by a negative regulatory protein, the result is:

 

repression of transcription

Which of these is not a genome?

 

I. DNA that is on multiple linear chromosomes

II. A circular plasmid that is separate from the chromosome 

III. A single circular chromosome

IV. A ribozyme

II and IV

Meselson and Stahl’s experiment demonstrated how DNA replication occurs by labeling the original DNA with heavy nitrogen (15-N), then replicating DNA to incorporate lighter, unlabeled nitrogen (14-N) into the new DNA strands. After at least two rounds of DNA replication, which of the following results are consistent with dispersive DNA replication?

All double helices composed of random amounts of 15-N and 14-N DNA

All of the following are associated with mitosis, except:

 

results in four haploid cells

An individual has genotype JjNn. If genes J and N are unlinked, then which of the following represents a normal gamete that this individual can make?

Jn

The Trp operon encodes five genes that promote synthesis of the amino acid tryptophan. This operon is transcribed at a high rate when tryptophan levels are low to allow cells to synthesize their own tryptophan. When tryptophan levels are high (when the cell has enough tryptophan from an external source), a protein called TrpR binds a DNA sequence near the Trp operon, and transcription of the Trp operon stops. TrpR acts as a:

 

Repressor

Which of these statements is true?

 

Mitosis and meiosis II both result in separation of sister chromatids

The images below show DNA molecules being replicated (top) from a template DNA strand (bottom). Thymine will be the next nucleotide added to the replicating strand in which image below? 

C

The “exome” is the collection of all transcribed sequences. Exome sequencing could be used to identify the specific change in nucleotide sequence for which of the following types of mutation?

 

A mutation in an exon

You are a Drosophila geneticist working on a yellow wing-color trait that is new to you. When you mate wildtype males to yellow-winged females, you observe 100% wildtype female offspring and 100% yellow-winged male offspring. You conclude the gene is:

 

X-linked dominant/recessive

Which of the following occurs in prokaryotes only?

 

co-regulation of genes using operons

How would DNA replication be affected if helicase were not functional?

 

The template strands would not be able to separate

For alleles of two different genes on two different chromosomes,___________ occurs because _________.

independent assortment, homologous chromosomes pair and align in the middle of the cell at metaphase

You are working with a gene that you know has an activator protein. If the activator sequence for this gene was deleted, then:

 

The gene would not have regulated transcription

In these diagrams, which lettered arrows span the time interval when the cells are haploid?

 E and F

A particular genome has approximately 20% Thymine base content. What is the approximate percentage of Cytosine bases in this genome?

30%

Which of the following demonstrates incomplete dominance?

 

purple, lavender, and white flowers on the same plant

Cells become _______ during ________ because of separation of sister chromatids.

haploid, meiosis I, separation of homologous chromosomes

In 1928, Fredrik Griffith exposed non-virulent bacteria to heat-killed virulent (disease-causing) bacteria, which converted the non-virulent bacteria into virulent bacteria. This experiment demonstrated that:

 

Bacteria can acquire hereditary information from their environment

One difference between prokaryotic and eukaryotic genomes is that only eukaryotes:

 

Have chromatin

Which of the following is true about co-regulation of genes in prokaryotes and eukaryotes?

 

Both prokaryotes and eukaryotes can perform co-regulation by having genes with identical regulatory elements