BIO101 Final

Which of the following statements describes Charles Darwin's most significant original contribution to understanding both the unity and the diversity of life?

He proposed a mechanism to explain the process of evolution

Which of the following represents the correct hierarchy of biological organization from large scale to smaller scale?

biosphere → ecosystems → communities → populations → organisms

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

It must lead to testable predictions.

Imagine there is a species-specific fishing regulation that mandates that only adult fish of this species that are 75 cm or longer may be kept; shorter fish must be released. Based on your knowledge of natural selection, how would you predict that the average length of the adult fish population might be affected?

Length would gradually decrease.

Investigating the molecular structure of DNA in order to understand the chemical basis of inheritance is an example of which approach utilized in the study of biology?

reductionism

Which of the following correctly describes the forms by which energy flows through an ecosystem from entry to exit?

light → chemical → heat

All the individuals of a particular species living within the bounds of a specified area are collectively described by which of the following terms?

a population

Which of the following is the best description of a control for an experiment?

The control group is matched with the experimental group except for the one experimental variable.

Which of the following molecules contains polar covalent bonds?

H2O

How many electron pairs are shared between the two carbon atoms in a molecule that has the formula C2H4?

2

Phosphorus-32, a radioactive isotope of phosphorus-31 (atomic number 15), undergoes a form of radioactive decay whereby a neutron turns into a proton, which is retained in the nucleus and emits radiation in the form of an electron. What is the product of such radioactive decay of phosphorus-32

sulfur-32 (atomic number 16)

The left-to-right position of an element in the first three rows of the periodic table indicates which of the following properties of the element?

The number of electrons in the valence shell

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.

Oxygen has an atomic number of 8 and a mass number of 16. What is the atomic mass of an oxygen atom?

approximately 16 daltons

Which bond or interaction would be most difficult to disrupt when compounds are put into water?

covalent bond

If a salamander clings to surfaces through hydrogen bonds, it would have the most difficulty clinging to which of the following surfaces?

a surface coated with a thin film of vegetable oil

Which of the following statements regarding lipids is true?

They are insoluble in water.

A molecule with the chemical formula C6H12O6 is most likely a

monosaccharide

Which of the following polymers are assembled with monomers containing nitrogen?

chitin

How many electron pairs does carbon share in order to complete its valence shell?

4

Which of the following structures is formed by the atoms involved when a carbon atom is bound by single covalent bonds to four other atoms?

tetrahedron

A carbon atom is most likely to form which of the following bonds with other atoms?

covalent bonds

The term insoluble fiber on food packaging generally refers to which of the following carbohydrates?

cellulose

Why are hydrocarbons insoluble in water?

The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.

Plastids are only found in which of the following types of cells or organisms?

plant cells

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

central vacuole

If plant cells are grown on media containing radioactively labeled thymine for one generation, where will radioactively labeled macromolecules be detected?

the nucleus, mitochondria, and chloroplasts

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

Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. Which of the following hypotheses is most plausible in light of such structural similarities?

Cilia and flagella are derived from the centrioles.

In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and

combine the hydrogen with oxygen molecules to generate hydrogen peroxide.

Which of the following statements concerning cells of bacteria and archaea is correct?

Chromosomes in both archaea and bacteria contain DNA.

The chemical reactions involved in respiration in prokaryotic and eukaryotic cells are virtually identical. In eukaryotic cells, ATP is synthesized primarily on the inner membrane of the mitochondria. In light of the endosymbiont theory for the evolutionary origin of mitochondria, where would you expect most ATP synthesis to occur in prokaryotic cells?

on the plasma membrane

Immediately after a membrane receptor protein binds to its ligand, which of the following processes occurs?

The membrane receptor protein undergoes a conformational change.

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.

Which of the following is true of integral membrane proteins?

They are usually transmembrane proteins.

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.

Steroid hormone receptors in animals tend to be

soluble proteins in the cytoplasm.

A protein that spans the phospholipid bilayer one or more times is

a transmembrane protein.

An integral membrane protein would have to be

amphipathic, with at least one hydrophobic and one hydrophilic region

The cytoplasmic side of a cell membrane is negative in charge relative to the extracellular side. What is the voltage across a cell membrane called?

membrane potential

Which of the following is an example of an anabolic pathway?

a set of reactions that combine monomers into larger, more energy-rich polymers

Which of the following processes would be an example of a catabolic pathway?

providing energy that can be used to drive cellular work

Anabolic pathways share which of the following characteristics?

They consume energy to synthesize polymers from monomers.

An enzyme-catalyzed reaction is conducted in a test tube with a fixed amount of enzyme. Increasing the substrate concentration in the test tube may overcome the effect of which of the following conditions?

presence of a fixed amount of a competitive inhibitor

Energy transformations in organisms are always associated with

an increase in the entropy of the universe.

Which of the following statements is a logical consequence of the second law of thermodynamics?

Every chemical reaction must increase the total entropy of the universe.

Hydrolysis of ATP releases energy, which ultimately results in the production of ADP and inorganic phosphate. What generally happens to the inorganic phosphate produced in the cytosol?

It is combined with ADP to regenerate ATP.

In addition to its critical role in cellular metabolism, ATP may also be described as which of the following?

an RNA nucleotide

In chemiosmosis, what is the most direct source of energy that is used to convert ADP + Pi to ATP?

energy released from movement of protons down their electrochemical gradient through ATP synthase

How many carbon atoms from one molecule of pyruvate enter the citric acid cycle?

2

In an oxidation-reduction reaction, how is the reducing agent changed?

It loses electrons and loses potential energy.

Which of the following statements correctly describes how ATP is involved in the oxidation of one molecule of glucose in glycolysis?

Two molecules of ATP are used, and four molecules of ATP are produced.

What is the primary role of oxygen in cellular respiration?

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

Which of the following molecules donates electrons directly to the electron transport chain at the lowest energy level?

FADH2

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

Which of the following statements about NAD+ is true?

NAD+ is reduced to NADH during glycolysis.

A plant-derived protein known as colchicine can be used to poison cells by blocking the formation of the mitotic spindle. Which of the following would result if colchicine is added to a sample of cells in G2?

Chromosomes would condense but fail to align at the metaphase plate, and the cell cycle would arrest at this point.

Which is the first checkpoint in the cell cycle that will cause a cell to exit the cycle if this point is not passed?

G1

When a cell is in late anaphase of mitosis, which of the following may be observed?

a clear area in the center of the dividing cell

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

32

Density-dependent inhibition is explained by which of the following statements?

As cells become more numerous, the cell surface proteins of adjacent cells bind to each other and send signals that inhibit cell division.

Movement of the chromosomes during anaphase would be most affected by a drug that prevents which of the following processes?

shortening of microtubules

Humans produce skin cells by mitosis and gametes by meiosis. Which of the following statements about the nuclei of skin cells is correct?

They contain twice as much DNA as the nuclei of gametes produced by meiosis.

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.

The leaves of a plant with a unique photosynthetic pigment appear orange in sunlight. What wavelengths of visible light are most likely absorbed by this unique pigment?

blue and violet

What is the relationship between wavelength of light and the quantity of energy per photon?

They are inversely related.

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

splitting of water molecules

What compound provides the reducing power for the Calvin cycle reactions?

NADPH

Where are ATP synthase complexes located in a plant cell?

thylakoid membranes and inner mitochondrial membranes

Why are C4 plants able to photosynthesize with no apparent photorespiration?

They do not use rubisco to fix CO2

Which of the following statements best represents the relationships between the light reactions and the Calvin cycle?

The light reactions provide ATP and NADPH to the Calvin cycle, and the Calvin cycle returns ADP, Pi, and NADP+ to the light reactions

What is the primary function of the Calvin cycle?

to produce simple sugars from carbon dioxide

Scientists have produced a hybrid plant that was the result of the fertilization of gametes between one plant with a diploid number of 24 and another with a diploid number of 20. How many chromosomes would the diploid hybrid plant have?

22 chromosomes

A given organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism?

Its gametes must have 23 chromosomes.

If chiasmata can be seen in a cell under a microscope, which of the following meiotic processes must have occurred?

prophase I

For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes?

approximately 8.4 million

The somatic cells of a type of shrub called a privet each contain 46 chromosomes. To be as different as they are from human cells, which have the same number of chromosomes, which of the following must be true?

Genes of privet chromosomes are significantly different from those in humans.

If a cell has completed the first meiotic division and is just beginning meiosis II, which of the following statements describes the genetic or chromosomal contents of this cell?

It has half the amount of DNA of the cell that began meiosis

In a cell undergoing meiosis, if homologous chromosomes are aligned at the equator of the meiotic spindle, what process has occurred?

metaphase I

Which of the following is true of an organism that has a chromosome number of 2n = 16?

Each cell has eight homologous pairs of chromosomes

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

pleiotropy

Which of the following calculations described in the following statements require that you use the addition rule?

Calculate the probability of a child having only sickle-cell anemia or cystic fibrosis if each parent is heterozygous for both traits.

Achondroplasia, a form of dwarfism in humans, is caused by a dominant allele. What is the probability of a heterozygous dwarf man and a normal, homozygous woman having a child who is a heterozygous dwarf?

50%

Which of the following statements correctly describes a dihybrid cross?

involves organisms that are heterozygous for two characters.

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

Given the following cross between parents of the genotypes AABBCc × AabbCc, assume complete dominance for each trait and independent assortment. What proportion of the progeny will be expected to phenotypically resemble the first parent?

3/4

What was Mendel's explanation for his observation that traits that had disappeared in the F1 generation reappeared in the F2 generation of the pea plants he used in his experiments?

Traits can be dominant or recessive, and the recessive traits were “hidden” by the dominant ones in the F1.

Why did the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties?

One allele was dominant.

Three genes (A, B, and C) at three loci are being mapped in a particular species. Each gene has two alleles, each of which results in a dominant or recessive phenotype. The dominant allele of gene A is inherited with the dominant allele of gene B or C about 50% of the time. However, the dominant alleles of genes B and C are inherited together 14.4% of the time. Which of the following statements describes what is happening regarding the inheritance of these genes?

Gene A is assorting independently of genes B and C, which are linked.

What evidence did Alfred Sturtevant use to support his conclusion that Drosophila have four pairs of chromosomes?

Drosophila genes cluster into four distinct groups of linked genes.

Of the following human aneuploidies, which is the one that generally has the most severe impact on the health of the individual?

47,+21,Down syndrome

Sex determination in mammals is due to the SRY gene on the Y chromosome. An abnormality of this region could allow which of the following individuals to have a male phenotype?

translocation of the SRY gene to an autosome of a 46,XX individual

Males are more often affected by sex-linked traits than females because

males are the hemizygous for the X chromosome

Which of the following statements correctly describes aneuploid conditions?

Monosomy X is the only known viable human monosomy.

How does the recombination of linked genes contribute to natural selection?

It maintains genetic variability in a species.

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

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

The genetic code is essentially the same for all organisms. Based on this information, one can logically assume which of the following statements to be correct?

A gene from an organism can theoretically be expressed by another organism.

During the process of alternative RNA splicing, where on a pre-mRNA transcript does a spliceosome bind?

on certain sequences of an intron

A particular triplet of bases in the template strand of DNA is 5'-AGT-3'. The corresponding codon for the mRNA transcribed is

3'-UCA-5'.

A mutation in a cell results in a structural change in the signal-recognition particle (SRP) so that it does not bind to the translocation complex in the ER correctly. Which of the following processes will occur because of this mutation?

Proteins produced during translation that are destined for the ER will not be translocated into the ER.