Bio 1610

Nicholas Pardikes

Which of the following statements best distinguishes hypotheses from theories in science?

Hypotheses usually are relatively narrow in scope; theories have broad explanatory power.

Which of the following is a requirement for a good scientific hypothesis?

It must lead to testable predictions.

Which of the following statements describes an individual that is likely to be the most successful in an evolutionary sense?

an organism that dies after five days of life but leaves 10 offspring, all of whom survive to reproduce

The variation observed among the finches Darwin collected from the Galápagos Islands illustrate which of the following principles associated with the evolution of species?

descent with modification

Buffers are substances that help resist shifts in pH by

accepting H+ from a solution when acids are added.

Why does ice float in liquid water?

The high surface tension of liquid water keeps the ice on top.

Trace elements are required by organisms in only minute quantities (less than 0.01% of mass). Which of the following is a trace element that is required by humans and other vertebrates?

iodine

How does the formation of covalent bonds differ from the formation of ionic bonds between two atoms?

Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the transfer of electrons from one atom to the other.

In an aqueous solution, water molecules associate with one another through which of the following?

hydrogen bonds

Which of the following takes place as an ice cube cools a drink?

Kinetic energy in the drink decreases.

In ammonium chloride salt (NH4Cl), the anion is a single chloride ion, (Cl¯). What is the cation of NH4Cl salt?

NH4, with a charge of +1

A solution contains 0.0000001 (10-7) moles of hydroxyl ions (OH-) per liter. Which of the following best describes this solution?

neutral

What structural feature makes the 20 common amino acids different from one another?

different side chains (R groups) attached to an α carbon

correct monomer/polymer pairing?

\
Polysaccharides Monosaccharides

Polypeptides and proteins Amino-acids

Nucleic acids Nucleotides

Which of the following large biological molecules will self-assemble into a bilayer when mixed with water?

phospholipids

Ibuprofen is a drug commonly used to relieve inflammation and pain. It is a mixture of two enantiomers, which are molecules that

are mirror images of one another.

If one strand of a DNA molecule has the sequence of bases 5'-ATTGCA-3', the other complementary strand would have the sequence

5'-TGCAAT-3'.

Which of the following chemical equations describes a dehydration reaction?

A+A=B+H2O

Which two functional groups shown in Figure 3.4 are present in all amino acids?

C and D

Approximately 32 different monomeric carbohydrate subunits are found in various natural polysaccharides. Proteins are composed of 20 different amino acids. DNA and RNA are each synthesized from four nucleotides. \n Which class of biological polymer has the greatest functional variety?

proteins

what is the difference between saturated and unsaturated lipid chains

The difference between saturated and unsaturated fat lies in the number of double bonds in the fatty acid chain. Saturated fatty acids lack double bonds between the individual carbon atoms, while in unsaturated fatty acids there is at least one double bond in the fatty acid chain.

A food company wishes to convert corn oil into a spread that is solid at room temperature. One way to accomplish this goal would be to 

add hydrogens, decreasing the number of double bonds in the oil molecules.

Which organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids?

smooth endoplasmic reticulum

Which plant cell organelle contains its own DNA and ribosomes?

mitochondrion

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

proteins

Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through

gap junctions.

Which organelle occupies much of the volume of a plant cell?

central vacuole

Which of the following statements correctly describes a function of the Golgi apparatus?

protein modification and sorting

Passive movement of fluids and bacteria from the interior of the small intestine through the space between cells of the intestinal wall can cause serious infection and medical complications. Defects in which of the following would be associated with such a condition?

tight junctions

Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to carry out which of the following processes?

separate chromosomes during cell division

Cyanide binds to at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the

mitochondria.

Tay-Sachs disease is a human genetic abnormality that results in cells accumulating very large, complex, undigested lipids. Which cellular organelle is likely to be defective in this condition?

the lysosome

The fluid mosaic model of membrane structure suggests that membranes

are composed of protein molecules embedded in a fluid bilayer of phospholipids.

Mammalian blood contains the equivalent of 0.15 *M* NaCl. Seawater contains the equivalent of 0.45 *M* NaCl. What will happen if red blood cells are transferred to seawater?

Water will leave the cells, causing them to shrivel and collapse.

Which of the following membrane activities requires energy from ATP hydrolysis?

movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cell

The difference between pinocytosis and receptor-mediated endocytosis is that

pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis is highly selective.

Based on the figure below, which of these experimental treatments would increase the rate of sucrose transport into a plant cell?

decreasing extracellular pH

Steroid hormone receptors in animals tend to be

soluble proteins in the cytoplasm.

When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?

signal molecule

At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogens and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects?

Estrogen binds to specific receptors inside many kinds of cells, each of which has different responses to its binding.

Estrogen binds to specific receptors inside many kinds of cells, each of which has different responses to its binding.

catabolism.

Which of the following descriptions would be an example of potential energy?

the chemical bonds in a molecule of sucrose

Which of the following statements is representative of the second law of thermodynamics?

Cells require a constant input of energy to maintain their high level of organization.

Based on the first law of thermodynamics, which of the following statements about a living organism is true?

The organism ultimately must obtain all of the necessary energy for life from its environment.

In order for a coupled reaction to have a net  of ‒3.3 kcal/mol,

the exergonic reaction needs to release more energy than the endergonic reaction requires.

A noncompetitive inhibitor decreases the rate of an enzymatic reaction by

changing the shape of the enzyme active site.

Which of the following describes the result of transferring an electron from a less electronegative atom to a more electronegative atom?

The more electronegative atom is reduced, and energy is released.

Refer to the figure showing the exergonic reaction that links glycolysis to the citric acid cycle. Which statement about the molecules participating in this cellular reaction is correct?

Pyruvate has higher stored free energy than acetyl CoA, and NADH has higher stored free energy than NAD+.

What is the primary role of oxygen in cellular respiration?

to serve as an acceptor for electrons and protons, forming water

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of

an endergonic reaction coupled to an exergonic reaction.

Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?

oxidation of pyruvate to acetyl CoA and the citric acid cycle

The complete oxidation of two molecules of glucose (C6H12O6) in cellular respiration produces about how many molecules of ATP?

60-64

Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms.

Which one of the following molecules is formed by the removal of a carbon (as CO2) from a molecule of pyruvate during aerobic respiration?

acetyl CoA

Which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle (see Figure 7.1)?

3 ATP, 3 CoA, 6 CO2, 9 NADH, and 3 FADH2

Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?

to oxidize NADH to NAD+

Yeast cells grown anaerobically can obtain energy by fermentation, which results in the production of

ATP, CO2, and ethanol.

Which of the following statements best describes the relationship between autotrophs and heterotrophs?

Autotrophs produce their organic molecules from CO2 and other inorganic molecules, whereas heterotrophs obtain their organic molecules from compounds produced by other organisms.

In mechanism, photophosphorylation is most similar to

oxidative phosphorylation in cellular respiration.

Which of the following reactions produces the oxygen released by photosynthesis?

splitting of water molecules

In the figure, how should boxes X, Y, and Z be labeled?

X = reduction and sugar production, Y = regeneration of RuBP, Z = carbon fixation

P680+ is said to be the strongest biological oxidizing agent. The strong oxidizing potential of P680+ is essential for its function because it

obtains electrons from the oxygen atom in a water molecule

Use Figure 8.2 and the compounds labeled A, B, C, D, and E to answer the following question. Which molecule in the Calvin cycle also serves as the substrate for the first step in the energy payoff phase of glycolysis?

c

A desert succulent plant is most likely performing what kind of photosynthesis?

CAM

In C3 plants the Calvin cycle occurs in the chloroplasts of mesophyll cells, whereas in C4 plants the Calvin cycle occurs in the

chloroplasts of the bundle sheath cells.

CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they

fix CO2 into organic acids during the night when temperatures are cooler.

Most simply described, what process drives the annual oscillation in CO2 concentrations shown below?

The balance between the rate of CO2 production by respiration and the rate of CO2¬ consumption by photosynthesis throughout the changing of seasons

During which phase of mitosis does the nuclear envelope re-form?

 

telophase

Beginning with a fertilized egg (zygote), how many cells would be present in an embryo following a series of five cell divisions?

 

32

Which phase(s) make up interphase in the eukaryotic cell cycle?

G0, G1, G2, and S, only

Eukaryotic cells spend most of their cell cycle in which phase?

interphase

The unlettered circle at the top of the figure above shows a diploid nucleus with four chromosomes that have not yet replicated. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is black, and the other is gray. The circles labeled A-E show various combinations of these chromosomes. What is the correct chromosomal condition for a nucleus at prophase of mitosis?

b

A group of cells is assayed for DNA content immediately before beginning mitosis and is found to have an average of 16 picograms of DNA per nucleus. How many picograms of DNA would be found in a cell nucleus following completion of mitosis and cytokinesis?

8

Taxol is an anticancer drug extracted from the Pacific yew tree that binds to microtubules and prevents their depolymerization. Which phase of mitosis or cell division would be inhibited by treatment with Taxol?

anaphase

Cells from advanced malignant tumors frequently have very abnormal chromosomes as well as an abnormal number of chromosomes. What might explain the association between malignant tumors and chromosomal abnormalities?

Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities.

A haploid cell is a cell

containing only one copy of each chromosome.

The major drawback of asexual reproduction, as compared with sexual reproduction, is that it

produces less variation among offspring.

Refer to the figure showing crossing over during meiosis.

prophase I.

Which phase of meiosis is represented in the figure above?

anaphase I

In some plants such as mosses and ferns, there is a multicellular stage in the life cycle that is haploid and a different stage that is diploid. What can you conclude from this?

Haploid cells must undergo mitosis to produce a multicellular haploid stage.

A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure above. If a female of this species has one chromosome 12 with a blue gene and another chromosome 12 with an orange gene, and has both number 19 chromosomes with short genes, she will produce which of the following egg types?

one-half blue short and one-half orange short gene eggs

When crossing an organism that is homozygous recessive for a single trait with one that is heterozygous for the same trait, what is the chance of producing an offspring with the homozygous recessive phenotype?

50%

Suppose members of a true-breeding strain of salamanders with yellow stripes are crossed with a true-breeding strain with red stripes. Red and yellow are two alleles of the same gene. The resulting offspring have both yellow stripes and red stripes. Which dominance pattern is most likely?

Red and yellow stripes exhibit codominance.

Which of the following describes the ability of a single gene to have multiple phenotypic effects?

pleiotropy

Skin color in humans has a wide variety of phenotypes. The expression of this trait is caused by more than two genes. What type of inheritance pattern is responsible for this expression?

polygenic inheritance

A sexually reproducing animal has two unlinked genes, one for head shape (*H*) and one for tail length (*T*). Its genotype is *HhTt*. Which of the following genotypes is possible in a gamete from this organism?

*HT*

Which of the following phases of cell division confirms Mendel's observation of the segregation of alleles in gamete formation?

anaphase I of meiosis

Which of the following statements correctly describes an example of epistasis?

In rabbits and many other mammals, one genotype (*ee*) prevents any fur color from developing.

Two true-breeding stocks of pea plants are crossed. One parent has red axial flowers, and the other has white terminal flowers; all F1 individuals have red axial flowers. The genes for flower color and location assort independently. Individuals from the F1 generation are crossed with each other to produce the F2 generation. Among the F2 offspring, what is the probability of plants with white and axial flowers?

3/16

All seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment. Which of the following statements correctly describes what this indicates about those traits?

All of the genes controlling the traits behaved as if they were located on different chromosomes.

Which of the following statements best describes the *SRY* gene?

It is a gene region present on the Y chromosome that triggers male development.

It is a gene region present on the Y chromosome that triggers male development.

They carry genes from two different parents.

A couple has a child with Down syndrome. The mother is 39 years old at the time of delivery. Which of the following is the most probable cause of the child's condition?

Nondisjunction occurred in one member of the couple during gamete production.

The figure below shows a map of four genes on a chromosome. Between which two genes would you expect the lowest frequency of recombination?

*W* and *E*

Which of the following statements describes the chromosome theory of inheritance as expressed in the early twentieth century?

Mendelian genes are at specific loci on the chromosome and in turn segregate during meiosis.

What is the reason that closely linked genes are typically inherited together?

The likelihood of a crossover event between these two genes is low.

White eyes are a recessive x-linked trait in *Drosophila*. If a white-eyed female fly is mated to a red-eyed male, their offspring should be

all white-eyed males and all red-eyed females.

In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of an orange female and a black male?

tortoiseshell females; orange males

In a nucleosome, the DNA is wrapped around

histones.

What is meant by the description "antiparallel" regarding the two strands of nucleic acids that make up DNA

The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.