full bio exam

Paired homologous chromosomes are found at the spindle equator during A. Prophase II B. Metaphase I C. Telophase I D. Anaphase II E. Metaphase II

B. Metaphase I

Meiotic cell division in animals occurs in the ___ and results in the production of ___ A. Testes and ovaries; diploid cells B. Testes and ovaries; gametes C. Body cells; parent cells D. Body cells; daughter cells

B. Testes and ovaries; gametes

The diploid number of chromosomes in mammals is always A. an odd number B. an even number C. 2 D. 23 E. 46

B. an even number

Nondisjunction during mitosis leads to: A. an individual with a clone of abnormal cells B. an individual with all abnormal cells C. death of the daughter cells D. nonviable sperm E. normal daughter cells

B. an individual with all abnormal cells

In the alternation of generations life cycle, adults may be A. diploid only B. haploid or diploid C. haploid only D. neither haploid nor diploid

B. haploid or diploid

An animal with a diploid number of 36 chromosomes will have___ chromosomes in its gametes and ___ chromosomes in its somatic cells A. 36; 36 B. 36; 72 C. 36; 18 D. 18; 36 E. 18; 18

D. 18; 36

Which of the following does NOT occur in prophase I of meiosis? A. Tetrad formation B. Synapsis C. Condensation of chromatin D. Crossing over E. Cytokinesis

E. Cytokinesis

Major gene reshuffling takes place during A. Metaphase II B. Anaphase II C. Anaphase I D. Prophase I E. Metaphase I

E. Metaphase I

In a human cell at prophase I, there are ___ tetrads A. 4 B. 23 C. 46 D. 92 E. 2

A. 92

If the DNA sequence is G-C-C-T-A-T in one polynucleotide chain, then the sequence found in the other polynucleotide chain must be A. C-G-G-A-T-A B. G-C-C-T-A-T C. A-T-T-C-G-C D. C-G-G-A-U-A

A. C-G-G-A-T-A

What is one difference in mitosis and meiosis during anaphase I? A. Chromatids do not separate at the centromere in anaphase I B. The chromosomes line up at the equator in anaphase I C. Centromeres do not exist in anaphase I D. Crossing over occurs only in anaphase of mitosis

A. Chromatids do not separate at the centromere in anaphase I

The hereditary material present in all cells is A. DNA B. RNA C. R-strain D. protein E. S-strain

A. DNA

How many daughter cells are produced from each parent cell during meiosis? A. Four B. Millions C. Two D. One

A. Four

How many haploid cells are produced by one diploid cell during meiosis? A. Four B. One C. Two D. 8 million

A. Four

Meiosis typically results in the production of A. Four haploid cells B. Two haploid cells C. Two diploid cells D. Four diploid cells E. One triploid cell

A. Four haploid cells

Anaphase I A. Homologous chromosomes separate and move to opposite poles B. Sister chromatids separate and chromosomes move to opposite poles C. Tetrads line up at the cell equator D. Crossing over occurs E. Nuclear envelope forms around single-stranded chromosomes

A. Homologous chromosomes separate and move to opposite poles

Complementary base pairs are held together by A. Hydrogen bonds B. Peptide bonds C. Disulfide bonds D. Ionic bonds E. Covalent bonds

A. Hydrogen bonds

This structure emanates from the centromere and contacts the spindle fibers during mitosis & meiosis A. Kinetochore B. Alpha satellite C. Euchromatin D. Subtelomere

A. Kinetochore

For a diploid organism with 6 chromosomes A. Meiosis II starts with 6 chromatids joined as 3 pairs of sister chromatids B. Mitosis begins with 6 chromatids joined as 3 pairs of sister chromatids C. Mitosis begins with 12 chromatids joined as 3 pairs of sister chromatids D. None of the above

A. Meiosis II starts with 6 chromatids joined as 3 pairs of sister chromatids

Strictly speaking, mitosis and meiosis are divisions of the A. Nucleus and chromosomes B. Nucleus, cytoplasm, and chromosomes C. Cytoplasm D. Nucleus E. Chromsomes

A. Nucleus and chromosomes

Which is NOT a typical site for the occurrence of meiosis? A. Plant root cells B. Human ovary C. Plant ovary D. Human testis E. Plant anther

A. Plant root cells

Metaphase I A. Tetrads line up at the cell equator B. Nuclear envelope forms around single-stranded chromosomes C. Crossing over occurs D. Sister chromatids separate and chromosomes move to opposite poles E. Homologous chromosomes separate and move to opposite poles

A. Tetrads line up at the cell equator

Telophase I A. Tetrads line up at the cell equator B. Sister chromatids separate and move to opposite poles C. Nuclear envelope forms around single stranded chromosomes D. Crossing over occurs E. A & D

A. Tetrads line up at the cell equator

The sequence of subunits in the DNA "backbone" is A. -base-phosphate-base-phosphate-base-phosphate- B. -phosphate-sugar-phosphate-sugar-phosphate-sugar- C. -sugar-base-sugar-base-sugar-base-sugar-base- D. -base-sugar-phosphate-base-sugar-phosphate- E. -base-phosphate-sugar-base-phosphate-sugar-

B. -phosphate-sugar-phosphate-sugar-phosphate-sugar-

Which of the following is NOT true according to Chargaff's base pairing rule? A. A + G = T + C in amount B. A + T = G = C in amount C. G = C in amount D. A = T in amount

B. A + T = G = C in amount

"Chargaff's rule" for base pairing in DNA is that A. A bonds with C, and G bonds with T B. A bonds with T, and G bonds with C C. A bonds with G, and C bonds with T D. The amount of A = the amount of G, and the amount of C = the amount of T E. The amount o A = the amount of C, and the amount of G = the amount of T

B. A bonds with T, and G bonds with C

During which stage of meiosis do the sister chromatids separate? A. Metaphase II B. Anaphase II C. Telophase II D. Metaphase I B. Anaphase I

B. Anaphase II

During meiosis, maternal, and paternal chromosomes can exchange genetic material at sites called A. Centrioles B. Chiasmata C. Centromeres D. Chromatids

B. Chiasmata

During prophase I of meiosis, homologous chromosomes lie side by side. This phenomenon is known as A. DNA replication B. Chromatid pairing C. Tetrad formation D. Paternal pairing E. Parental pairing

B. Chromatid pairing

Chiasmata are the locations of A. Sister chromatid attachment B. Crossing over C. Meiosis D. Mitosis

B. Crossing over

In nondisjunction, which parent leads to the sex chromosome aneuloid XYY? A. Mother. B. Father C. either parent D. both parents

B. Father

Which of the following is NOT true of human chromosomes? A. Human gametes end up with two of each type of 23 chromosomes B. Human gametes end up with one of each type of 23 chromosomes C. The haploid number is 23 D. The diploid number is 46 E. There are 23 pairs of chromosomes

B. Human gametes end up with one of each type of 23 chromosomes

Crossing over is one of the most important events in meiosis because A. The number of chromosomes allotted to each daughter cell must be halved B. It produces new arrays of alleles on chromosomes C. Homologous chromosomes must be separated into different daughter cells D. Homologous chromatids must be separated into different daughter cells E. All of the choices are correct

B. It produces new arrays of alleles on chromosomes

The different forms of a gene for example, those responsible for eye color are called A. Receptors B. Sister chromatids C. Telomeres D. Cyclins E. Alleles

E. Alleles

The diploid number of chromosomes on a human skin cell is 46. What is the number of chromosomes found in a human egg cell? A. 12.5 B. 184 C. 23 D. 46 E. 92

C. 23

Chromosomes in humans are A. 44 homologous pairs, and 2 heterologus B. 22 pairs of autosomal chromosomes and one pair of of sex chromosome C. A & B D. None of the above

C. A & B

All of the following are found in DNA EXCEPT A. Thymine B. Deoxyribose C. A phospholipid group D. A phosphate group E. guanine

C. A phospholipid group

In meiosis, sister chromatids separate during A. Prophase I B. Prophase II C. Anaphase II D. Cytokinesis E. Anaphase I

C. Anaphase II

How does anaphase of mitosis differ from anaphase I of meiosis? A. In anaphase of mitosis, homologous chromosomes separate, but in anaphase I of meiosis, sister chromatids separate B. In anaphase of mitosis, sister chromatids join together, but in anaphase I of meiosis, homologous chromosomes join together C. In anaphase of mitosis, sister chromatids separate, but in anaphase I of meiosis, homologous chromosomes separate D. Sister chromatids do not separate in mitosis, but in anaphase I of meiosis, sister chromosomes do separate

C. In anaphase of mitosis, sister chromatids separate, but in anaphase I of meiosis, homologous chromosomes separate

What is a major difference between mitosis and meiosis? A. Mitosis produces daughter cells, whereas meiosis produces parent cells B. Meiosis produces two daughter cells instead of the four daughter cells produced in mitosis C. Meiosis produces haploid cells, whereas mitosis produces diploid cells D. Meiosis produces genetically identical daughter cells, whereas mitosis produces genetically variable daughter cells

C. Meiosis produces haploid cells, whereas mitosis produces diploid cells

Homologous chromosomes can be identified and/or characterized by A. Paternal chromosomes only B. Maternal chromosomes only C. Their similar and characteristic staining patterns D. The different centromere positions in the maternal versus paternal chromosomes E. Those chromosomes that do not have partners

C. Their similar and characteristic staining patterns

During meiosis, the cytokinesis that follows telophase II results in (the very end result) A. four diploid cells B. two haploid cells C. four haploid cells D. two diploid cells

C. four haploid cells

In flowering plants, pollen represents the A. zygote B. diploid stage C. haploid stage

C. haploid stage

In eukaryotes, gametes are produced by A. budding B. mitosis C. meiosis D. prokaryotic fission

C. meiosis

In a haploid daughter cell produced by meiosis, the homologous chromosomes have A. Multiplied B. Mutated. C. separated D. remained attached

C. separated

The "rule" formulated by Chargaff states that A. DNA and RNA are made up of the same four nitrogenous bases B. A = C and G = T in any molecule of DNA C. A = U and G = C in any molecule of RNA D. A = T and G = C in any molecule of DNA E. A = G and C = T in any molecule of DNA

D. A = T and G = C in any molecule of DNA

Under favorable conditions, during which phase of meiosis will the chromosomes appear as packets of four chromatids? A. Prophase I B. Metaphase II C. Telophase II D. Anaphase I E. Anaphase II

D. Anaphase I

If a child more strongly resembles one parent's physical traits than the other parent's, the explanation could be due to chromosome movements during A. Telophase B. Anaphase I C. Metaphase II D. Anaphase II E. Prophase II

D. Anaphase II

Which of the following is unique to mitosis and not a part of meiosis? A. Homologous chromosomes pair, forming bivalents B. Homologous chromosomes cross over C. Homologous chromosomes behave independently D. Chromatids are separated during anaphase

D. Chromatids are separated during anaphase

Which of the following events does NOT occur in prophase II but does occur in prophase I? A. Crossing over, synapsis, and spindle formation B. Synapsis C. Crossing over D. Crossing over and synapsis only E. Spindle formation

D. Crossing over and synapsis only

Which of the following does NOT provide new genetic combinations? A. Crossing over B. Random fertilization C. Independent assortment D. Cytokinesis

D. Cytokinesis

In the comparison of a DNA molecule to a twisted ladder, the upright sides of the ladder are A. Hydrogen bonds between bases B. Nitrogen bases linked to phosphate C. Deoxyribose linked to sulfate D. Deoxyribose linked to phosphate E. Nitrogenous bases linked together

D. Deoxyribose linked to phosphate

Gametophyte plants produce gametes using A. Polyploidy B. Mitosis C. Meiosis D. Fertilization

D. Fertilization

Which of the following occurs as a result of meiosis? A. Diploid nuclei with unpaired chromosomes are produced from haploid parent nuclei B. Haploid nuclei with unpaired chromosomes are produced from diploid parent nuclei with paired chromosomes C. Haploid nuclei with paired chromosomes are produced from diploid parent nuclei with unpaired chromosomes D. Haploid nuclei with unpaired chromosomes are produced from diploid parent nuclei with paired chromosomes

D. Haploid nuclei with unpaired chromosomes are produced from diploid parent nuclei with paired chromosomes

Homologous chromosomes undergo synapsis during A. Anaphase II B. Prophase II C. Telophase II D. Prophase I E. Anaphase I

D. Prophase I

Some organisms are capable of asexual or sexual reproduction. Under favorable conditions, reproduction proceeds asexually. When conditions become more stressful, reproduction switches to a sexual mode. Why? A. Asexual reproduction requires more energy B. Sexual reproduction produces individuals with new combinations of recombined chromosomes increasing diversity C. Sexual reproduction requires two separate individuals who can mutually provide nutrient support during stress D. Sexual reproduction is simple and more rapid, allowing large numbers of offspring to be produced

D. Sexual reproduction is simple and more rapid, allowing large numbers of offspring to be produced

Which of the following cell types is not used to examine chromosomes? A. white blood cells B. red blood cells C. bone marrow cells D. all of the above can be used

D. all of the above can be used

Different, or alternative, forms of the same gene are called A. homologous B. mutants C. chromatids D. alleles E. genetomorphs

D. alleles

When gametes fuse during fertilization, a(n) ___ is produced A. egg B. sperm C. haploid individual D. zygote

D. zygote

The diploid number of chromosomes on a human skin cell is 46. What is the number of chromosomes found in a human egg cell? A. 12.5 B. 46 C. 92 D. 184 E. 23

E. 23

Prophase I A. Homologous chromosomes undergo synapsis B. Nuclear envelope forms around single-stranded chromosomes C. Sister chromatids separate and chromosomes move to opposite poles D. Crossing over occurs E. A & D

E. A & D

In the comparison of a DNA molecule to a twisted ladder, the rungs (footholds) of the ladder are A. Deoxyribose linked to phosphate B. Deoxyribose linked to sulfate C. The backbones of the molecule D. Nitrogenous bases linked to phosphate E. Nitrogenous bases linked together

E. Nitrogenous bases linked together

Telophase II A. Tetrads line up at the cell equator B. Homologous chromosomes separate and move to opposite poles C. Nuclear envelope forms around single-stranded chromosomes D. Sister chromatids separate and move to opposite poles E. None of the above

E. None of the above

The sex-determining chromosomes of a human male are the A. Y and Y chromosomes B. X and X chromosomes C. Z and Z chromosomes D. X and Y chromosomes E. X and Y chromosomes

E. X and Y chromosomes

Four of the five answers listed below are haploid. Select the exception. A. Meiospore B. Gametophyte C. Egg D. Sperm E. Zygote

E. Zygote

A DNA nucleotide is made up of A. phospholipid-deoxyribose-base B. phospate-deoxyribose-base C. base-phosphate-glucose D. phosphate-deoxyribose-phosphate-deoxyribose E. adenine-thymine-guanine-cytosine

E. adenine-thymine-guanine-cytosine

In DNA, phosphate groups bond to A. ribose B. adenine C. other phosphate groups D. pyrimidine bases E. deoxyribose

E. deoxyribose

Crossing over A. occurs between sister chromatids B. is followed immediately by separation of each of the chromatids C. increases variability in gametes D. prevents genetic recombination E. results in only one exchange per homologue

E. results in only one exchange per homologue

If meiosis did NOT occur in sexually reproducing organisms A. mitosis would be sufficient B. gametes would be haploid C. growth of zygote would be halted D. eggs would be haploid, but sperm would be diploid E. the chromosome number would double in each generation

E. the chromosome number would double in each generation