Mastering Biology Multiple Choice Questions (For Exam 1) *Complete*

Two organisms with genotype AaBbCcDdEE mate. These loci are all independent. What fraction of the offspring will have the same genotype as the parents? A. 1/4 B. 9/64 C. 3/4 D. 4/3 E. 1/16

1/16

If a hypothetical organism has 5 chromosomes in one of its gametes, then how many chromosomes must it have in a body cell? A. 5 B. 10 C. 15 D. 20 E. the answer cannot be determined

10

The diameter of a typical eukaryotic cell is approximately ten times the diameter of a typical prokaryote. What is the ratio of the volume of typical eukaryotic:prokaryotic cells? A. 10:1 B. 1000:1 C. 100:1

1000:1

A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes. A. 30 B . 8 C. 16 D. 32 E. 64

16

Normal human gametes carry _____ chromosomes. A. 23 pairs of B. 46 C. 46 pairs of D. 5 E. 23

23

Two mice are heterozygous for albinism (Aa) . The dominant allele (A) codes for normal pigmentation, and the recessive allele (a) codes for no pigmentation. What percentage of their offspring would have an albino phenotype? A. 100 B. 50 C. 25 D. 75

25

If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be A. 0.25x. B. 0.5x. C. x. D. 2x. E. 4x.

2x

What number and types of chromosomes are found in a human somatic cell? a. 22 autosomes and 1 sex chromosome b. n chromosomes c. 44 autosomes and 2 sex chromosomes d. 21 autosomes and 2 sex chromosomes e. 45 autosomes and 1 sex chromosome

44 autosomes and 2 sex chromosomes

A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain? A. 46 B. 23 or 46, depending on the portion of prophase examined C. 23 D. 92 E. 46 or 92, depending on the portion of prophase examined

92

What is the difference between heterozygous and homozygous individuals? A. The homozygote will express the dominant trait and the heterozygote will express the recessive trait. B. Homozygotes have one chromosome while heterozygotes have two similar chromosomes. C. Heterozygotes carry two copies of a gene while homozygotes only carry one. D. All of the gametes from a homozygote carry the same version of the gene while those of a heterozygote will differ.

All of the gametes from a homozygote carry the same version of the gene while those of a heterozygote will differ.

_____ are the main male hormones. A. Progesterones B. Mineralocorticoids C. Androgens D. Luteinizing hormones E. Estrogens

Androgens

Which of the following appears to be true according to current research? A. There is no relationship between Helicobacter pylori and esophageal cancer in humans. B. As the population of Helicobacter pylori increases in the human body, cases of esophageal cancer also increase. C. As the population of Helicobacter pylori decreases in the human body, cases of esophageal cancer increase. D. As the population of Helicobacter pylori decreases in the human body, cases of esophageal cancer also decrease.

As the population of Helicobacter pylori decreases in the human body, cases of esophageal cancer increase.

Two sister chromatids are joined at the centromere prior to meiosis. Which statement is correct? A. Barring mutation, the two sister chromatids must be identical. B. The cell that contains these sister chromatids must be haploid. C. These chromatids make up a diploid chromosome.

Barring mutation, the two sister chromatids must be identical.

How do cancer cells differ from normal cells? A. Cancer cells may be immortal. B. Cancer cells trigger chromosomal changes in surrounding cells. C. Cultured cancer cells exhibit anchorage dependence.

Cancer cells may be immortal.

How could the botanist best determine whether the genotype of the green-pod plant is homozygous or heterozygous? A. Cross the green-pod plant with a yellow-pod plant. B. Self-pollinate the green-pod plant. C. Cross the green-pod plant with another green-pod plant.

Cross the green-pod plant with a yellow-pod plant.

Which molecules do not normally cross the nuclear membrane? A. mRNA B. Proteins C. DNA D. Nucleotide triphosphates

DNA

The parent cell that enters meiosis is diploid, whereas the four daughter cells that result are haploid. Which statement correctly describes how cellular DNA content and ploidy levels change during meiosis I and meiosis II? A. DNA content is halved only in meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II. B. DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II. C. DNA content is halved only in meiosis I. Ploidy level changes from diploid to haploid only in meiosis II. D. DNA content is halved only in meiosis I. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II. E. DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid only in meiosis II.

DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II.

Which of the following is found in binary fission but not in mitosis? A. The result produces 2 nuclei. B. Replication of DNA begins at an origin. C. Duplicated chromosomes attach to the plasma membrane. D. Following the process, a membrane separates the 2 copies. E. Replicated strands of DNA separate.

Duplicated chromosomes attach to the plasma membrane.

Which statement provides the best description of the interphase portion of the cell cycle? A. Interphase is a resting stage prior to cell division. B. Interphase is a brief period between mitosis and chromosome duplication. C. During interphase, a cell is metabolically active.

During interphase, a cell is metabolically active.

If a eukaryotic cell is in the G1 phase of the cell cycle, which statement about the cell's chromosomes must be correct? A. Each chromosome is made of a complex of DNA and associated proteins. B. Each chromosome consists of two identical chromatids. C. The chromosomes are preparing for DNA synthesis.

Each chromosome is made of a complex of DNA and associated proteins.

True or false? In diploid organisms, a dominant phenotype will only be expressed if the individual is homozygous dominant for that trait. A. True B. False

False

True or false? Large proteins containing a nuclear localization signal (NLS) bind to the nuclear pore and enter the nucleus without any expenditure of energy. A. True B. False

False

A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in A. prophase. B. metaphase. C. G2. D. anaphase. E. G1.

G1

Cells will usually divide if they receive the proper signal at a checkpoint in which phase of the cell cycle? A. cytokinesis B. G1 C. M D. G2 E. S

G1

Which of the following correctly matches a phase of the cell cycle with its description? A. G2: cell division B. S: immediately precedes cell division C. G1: follows cell division D. M: duplication of DNA E. All of the above are correctly matched.

G1: follows cell division

The cell cycle control systems of cancer cells differ from those of normal cells. Select the best explanation for this fact. A. Cancer cells are immortal. B. Genetic changes alter the function of the cancer cell's protein products. C. Cancer cells divide excessively and invade other tissues.

Genetic changes alter the function of the cancer cell's protein products.

How are sister chromatids and homologous chromosomes different from each other? A. They are not different. Homologous chromosomes and sister chromatids are both identical copies of each other. B. Homologous chromosomes contain the same gene loci but may have different alleles of a particular gene. Sister chromatids are identical copies of each other produced during DNA replication. C. Homologous chromosomes are identical copies of each other. One sister chromatid comes from the father, and one comes from the mother. D. Sister chromatids are only formed during mitosis. Homologous chromosomes are formed during meiosis. E. Homologous chromosomes are closely associated with each other in both mitosis and meiosis. Sister chromatids are only associated with each other during mitosis.

Homologous chromosomes contain the same gene loci but may have different alleles of a particular gene. Sister chromatids are identical copies of each other produced during DNA replication.

During _____ the cell grows and replicates both its organelles and its chromosomes. A. S B. G1 C. cytokinesis D. interphase E. mitosis

Interphase

If an organism with the genotype AaBb produces gametes, what proportion of the gametes would be Bb? A. 3/4 B. 1/4 C. None D. 1/2

None

Nucleoplasmin is a nuclear protein. This protein was divided into two segments and linked to the same large cytoplasmic protein, generating two fusion proteins. After injecting these fusion proteins into a cell, one of the proteins was found in the nucleus and the other in the cytoplasm. Which of the following conclusions can be drawn from these results? A. Nucleoplasmin does not have a nuclear localization signal. B. Only one of the two fusion proteins possesses a nuclear localization signal. C. One of the fusion proteins entered the nucleus by passive transport. D. The cytoplasmic protein contains a nuclear localization signal.

Only one of the two fusion proteins possesses a nuclear localization signal.

A small protein (molecular weight = 25,000 daltons) is injected into a cell and observed in the nucleus a short time later. What type of transport has taken place? A. Active transport B. Passive transport C. Osmosis

Passive transport

Select the correct statement describing cellular structure or function. A. Plant and animal cells both carry out cellular respiration, producing ATP. B. Mitochondria and chloroplasts are part of the endomembrane system of the eukaryotic cell. C. Only plant cells contain chloroplasts, and only animal cells contain mitochondria.

Plant and animal cells both carry out cellular respiration, producing ATP.

Which of the following occurs during meiosis but not during mitosis? A. Chromosomes condense. B. A spindle apparatus forms. C. Chromosomes align at the metaphase plate. D. Chromosomes migrate to opposite poles. E. Synapsis occurs.

Synapsis occurs.

During _____ both the contents of the nucleus and the cytoplasm are divided. A. the mitotic phase B. S C. G1 D. mitosis E. G2

The mitotic phase

Which of the following statements about the nuclear envelope is false? A. Nuclear pores are made up of a group of proteins that are collectively called the nuclear pore complex. B. The nuclear envelope is continuous with the Golgi apparatus. C. The nuclear envelope is composed of two lipid bilayers. D. Molecules pass into and out of the nucleus through nuclear pores.

The nuclear envelope is continuous with the Golgi apparatus.

Which of the following is true of kinetochores? A. They attach to the ring of actin along the cytoplasmic surface of the plasma membrane, causing the actin to contract to form the cleavage furrow. B. They are sites at which microtubules attach to chromosomes. C. They are the primary centromere structures that maintain the attachment of the sister chromatids prior to mitosis. D. They interdigitate at the cell's equator and then move apart, causing the cell to elongate. E. They are located at the center of the centrosome; their function is to organize tubulin into elongated bundles called spindle fibers.

They are sites at which microtubules attach to chromosomes.

What is true of all cancers? A. They are caused by chemical carcinogens. B. They are inherited. C. They have escaped normal cell cycle controls.

They have escaped normal cell cycle controls.

Why is it difficult to observe individual chromosomes with a light microscope during interphase? A. They have uncoiled to form long, thin strands. B. They leave the nucleus and are dispersed to other parts of the cell. C. The spindle must move them to the metaphase plate before they become visible. D. Sister chromatids do not pair up until division starts. E. The DNA has not been replicated yet.

They have uncoiled to form long, thin strands.

Why is it difficult to observe individual chromosomes with a light microscope during interphase? A. They leave the nucleus and are dispersed to other parts of the cell. B. The DNA has not been replicated yet. C. Sister chromatids do not pair up until division starts. D. The spindle must move them to the metaphase plate before they become visible. E. They have uncoiled to form long, thin strands.

They have uncoiled to form long, thin strands.

Why do some species employ both mitosis and meiosis, whereas other species use only mitosis? A. They need only mitosis to make large numbers of cells such as sperm. B. They need meiosis if the cells are producing organs such as ovaries. C. They need both if they are producing animal gametes. D. A single-celled organism only needs mitosis. E. They need only meiosis if they produce egg cells.

They need both if they are producing animal gametes.

Which of the following is true of benign tumors, but not malignant tumors? A. They can divide indefinitely if an adequate supply of nutrients is available. B. They remain confined to their original site. C. They are the result of the transformation of normal cells. D. They have an unusual number of chromosomes. E. They migrate from the initial site of transformation to other organs or tissues.

They remain confined to their original site.

In experiments to test whether a protein can enter the nucleus, why would proteins be labeled with fluorescent molecules? A. To make the proteins bigger B. To make the proteins easy to see C. To give the protein molecules energy D. To target the proteins to the nucleus

To make the proteins easy to see

True or false? The same phenotype can be produced by more than one genotype. A. True B. False

True

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely A. an animal cell in the process of cytokinesis. B. a plant cell in metaphase. C. a bacterial cell dividing. D. an animal cell in the S phase of the cell cycle. E. a plant cell in the process of cytokinesis.

a plant cell in the process of cytokinesis.

A human cell containing 22 autosomes and a Y chromosome is A. a sperm. B. an egg. C. a zygote. D. a somatic cell of a male. E. a somatic cell of a female.

a sperm.

Which of these is NOT a carcinogen? A. testosterone B. UV light C. cigarette smoke D. fat E. all of the above are carcinogens

all of the above are carcinogens

What is an allele? A. a type of chromosome B. the recessive form of a gene C. a variety of pea plant used by Mendel D. the dominant form of a gene E. an alternative version of a gene

an alternative version of a gene

Centromeres divide and sister chromatids become full-fledged chromosomes during _____. A. telophase B. anaphase C. metaphase D. interphase E. prometaphase

anaphase

Homologous chromosomes migrate to opposite poles during _____. A. metaphase II B. metaphase I C. anaphase I D. prophase II E. telophase II and cytokinesis

anaphase I

During _____ sister chromatids separate. A. metaphase I B. interphase C. prophase I D. prophase II E. anaphase II

anaphase II

What hormone promotes water retention by the kidneys? A. follicle-stimulating hormone (FSH) B. prolactin C. antidiuretic hormone (ADH) D. melatonin E. glucagon

antidiuretic hormone (ADH)

Which hormone opposes the action of parathyroid hormone? A. calcitonin B. insulin C. thyroxine D. thymosin E. glucagon

calcitonin

In the cells of some organisms, mitosis occurs without cytokinesis. This will result in A. cells lacking nuclei. B. destruction of chromosomes. C. cell cycles lacking an S phase. D. cells with more than one nucleus. E. cells that are unusually small.

cells with more than one nucleus.

What is the point of attachment between two duplicated chromosomes called? A. chromosome B. centrosome C. centromere D. telomere E. tetrad

centromere

Hormones are _____. A. signals that must interact with DNA in order to be effective B. produced only in response to environmental stress C. chemical signals between cells, transported in blood or hemolymph D. are all under the control of the pituitary gland E. always proteins

chemical signals between cells, transported in blood or hemolymph

Cytochalasin B is a chemical that disrupts microfilament formation. How would this interfere with cell division? A. DNA replication B. formation of the cell plate C. binary fission D. cleavage E. formation of the mitotic spindle

cleavage

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B? A. cell elongation during anaphase B. spindle formation C. cleavage furrow formation and cytokinesis D. spindle attachment to kinetochores E. DNA synthesis

cleavage furrow formation and cytokinesis

In eukaryotic cells DNA has the appearance of a _____. A. single strand B. letter U C. double helix D. triple helix E. circle

double helix

Which of these hormones are responsible for the "fight or flight" response to danger? A. insulin and glucagon B. thyroxine and calcitonin C. androgens and estrogens D. antidiuretic hormone (ADH) and oxytocin E. epinephrine and norepinephrine

epinephrine and norepinephrine

_____ is a carcinogen that promotes colon cancer. A. fat B. UV light C. estrogen D. a virus E. testosterone

fat

You are developing a new drug that damages the cells that provide the supportive structure required by a tumor. Which type of cell are you targeting? A. endothelial cell B. fibroblast C. parafollicular cell D. immune system cell

fibroblast

Meiosis II typically produces _____ cells, each of which is _____. A. four ... identical to the other B. four ... diploid C. four ... haploid D. two ... haploid E. two... diploid

four ... haploid

Consider pea plants with the genotypes GgTt and ggtt . These plants can each produce how many type(s) of gametes? A. one ... one B. four ... two C. four ... one D. two... one E. one ... two

four ... one

When constructing a Punnett square, the symbols on the outside of the boxes represent _______, while those inside the boxes represent _______. A. parents, gametes B. progeny, gametes C. gametes, progeny D. gametes, parents

gametes, progeny

Which of the following codes for proteins? A. chromosomes B. enzymes C. RNA D. genes

genes

Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress. A. melatonin B. insulin C. glucocorticoids D. thymosin E. parathyroid hormone

glucocorticoids

Which of these glands secretes releasing hormones? A. hypothalamus B. adrenal cortex C. thymus D. ovaries E. testes

hypothalamus

Mendel worked _____. A. on gene mapping B. in a monastery C. on the Human Genome Project D. with fruit flies E. on problems involving characters that were inherited together more often than expected by chance

in a monastery

Nucleoli are present during _____. A. anaphase B. metaphase C. prometaphase D. prophase E. interphase

interphase

In some organisms, such as certain fungi and algae, cells undergo the cell cycle repeatedly without subsequently undergoing cytokinesis. What would result from this? A. inability to duplicate DNA B. a decrease in chromosome number C. division of the organism into many cells, most lacking nuclei D. large cells containing many nuclei E. a rapid rate of gamete production

large cells containing many nuclei

Genetic variation occurs when chromosomes are shuffled in fertilization and what other process?. A. genetic drift B. natural selection C. mitosis D. meiosis E. mutation

meiosis

Human gametes are produced by _____. A. fertilization B. asexual reproduction C. mitosis D. the cell cycle E. meiosis

meiosis

During what stage do chromosomes line up by homologous pairs? A. mitosis only B. meiosis I only C. meiosis II only D. either mitosis or meiosis I E. either meiosis I or meiosis II

meiosis I only

Homologous chromosomes move toward opposite poles of a dividing cell during A. binary fission. B. fertilization. C. meiosis II. D. mitosis. E. meiosis I.

meiosis I.

Which structure is common to plant and animal cells? A. mitochondrion B. central vacuole C. chloroplast D. wall made of cellulose E. centriole

mitochondrion

What goes on continuously in most parts of the body, rather than just the gonads? A. mitosis B. meiosis C. gametogenesis D. both mitosis and meiosis E. none of the above

mitosis

Which of the following is a correct match of cell type with structure? A. nerve cell ... closely joined B. skin cell ... has a large volume C. intestinal cell ... closely joined D. muscle cell ... has proteins that slide back and forth E. skin cell ... has long extensions

muscle cell ... has proteins that slide back and forth

DNA is composed of building blocks called _____. A. nucleic acids B. Gs C. nucleotides D. adenines E. amino acids

nucleotides

Asexual reproduction _____. A. is limited to plants B. requires both meiosis and mitosis C. leads to a loss of genetic material D. produces offspring genetically identical to the parent E. is limited to single-cell organisms

produces offspring genetically identical to the parent

Spindle fibers attach to kinetochores during _____. A. interphase B. metaphase C. telophase D. anaphase E. prometaphase

prometaphase

Chromosomes become visible during _____. A. prophase B. metaphase C. prometaphase D. interphase E. anaphase

prophase

Synapsis occurs during _____. A. prophase I B. prophase II C. metaphase II D. telophase I and cytogenesis E. anaphase II

prophase I

During _____ a spindle forms in a haploid cell. A. metaphase II B. prophase II C. anaphase II D. telophase I and cytokinesis E. prophase I

prophase II

Which of the following does not occur during mitosis? A. replication of the DNA B. separation of the spindle poles C. condensation of the chromosomes D. spindle formation E. separation of sister chromatids

replication of the DNA

Which of the following is present in a prokaryotic cell? A. mitochondrion B. nuclear envelope C. ribosome D. chloroplast E. ER

ribosome

In alternation of generations, what is the diploid stage of a plant that follows fertilization called? A. spore B. chiasmata C. gametophyte D. karyotype E. sporophyte

sporophyte

Cytokinesis often, but not always, accompanies _____. A. metaphase B. telophase C. interphase D. prometaphase E. anaphase

telophase

At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids. A. interphase B. metaphase II C. telophase D. telophase II E. telophase I

telophase I

At the end of _____ and cytokinesis there are four haploid cells. A. anaphase I B. prophase II C. interphase D. telophase II E. prophase I

telophase II

What is crossing over? A. also referred to as the "independent assortment of chromosomes" B. the movement of genetic material from one chromosome to a nonhomologous chromosome C. the exchange of homologous portions of nonsister chromatids D. making an RNA copy of a DNA strand E. a direct consequence of the separation of sister chromatids

the exchange of homologous portions of nonsister chromatids

At the start of ______, the chromosomes are duplicated and lined up by homologous pair. A. the start of mitosis B. just before mitosis C. the start of meiosis II D. the start of meiosis I E. just after meiosis I

the start of meiosis I

Which of the following attributes is common to both prokaryotic cells and eukaryotic cells? A. membrane-enclosed organelles B. a membrane-enclosed nucleus C. the use of DNA as the information storage molecule D. the use of proteins as information storage molecules E. generally about the same size

the use of DNA as the information storage molecule

Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____. A. transferring of information from DNA to messenger RNA B. linking of nucleotides to form a polypeptide C. translation of a DNA nucleotide sequence into a sequence of amino acids D. translation of an RNA nucleotide sequence into a sequence of amino acids E. removal of introns from RNA and the stitching together of exons

transferring of information from DNA to messenger RNA

A tall, purple-flowered pea plant (TtPp) is allowed to self-pollinate. (The recessive alleles code for short plants and white flowers.) The phenotypic ratio of the resulting offspring is 9:3:3:1. What is the genotype of the plant whose phenotype appeared once out of every 16 offspring (the "1" in the 9:3:3:1 ratio)? A. TTpp B. ttpp C. TtPp D. TTPP

ttPP

Meiosis I produces _____ cells, each of which is _____. A. two... diploid B. two ... haploid C. two... identical to the other D. four ... haploid E. four ... diploid

two ... haploid

During prophase a homologous pair of chromosomes consists of _____. A. two chromosomes and four chromatids B. one chromosome and four chromatids C. one chromosome and two chromatids D. four chromosomes and two chromatids E. two chromosomes and two chromatids

two chromosomes and four chromatids

Mitosis results in the formation of how many cells; meiosis results in the formation of how many cells? A. two diploid cells ... two diploid cells B. four diploid cells ... four haploid cells C. two diploid cells ... four haploid cells D. four haploid cells ... two diploid cells E. two diploid cells ... two haploid cells

two diploid cells ... four haploid cells

Which of the following clues would tell you if a cell is prokaryotic or eukaryotic? A. the presence or absence of a rigid cell wall B. whether or not the cell contains DNA C. the presence or absence of ribosomes D. whether or not the cell is partitioned by internal membranes E. whether or not the cell carries out cellular metabolism

whether or not the cell is partitioned by internal membranes

If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis II would be A. 0.25x. B. 0.5x. C. x. D. 2x. E. 4x

x.