1) If a horticulturist breeding gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following would be her most probable and efficient route to establishing a line of such plants?
A) Backtrack through her previous experiments to obtain another plant with the same traits.

B) Breed this plant with another plant with much weaker traits

C) Clone the plant.
D) Force the plant to self-pollinate to obtain an identical one.

Answer: C

2) Which of the following defines a genome?
A) the complete set of an organism's polypeptides
B) the complete set of a species' polypeptides
C) a karyotype
D) the complete set of an organism's genes and other DNA sequences

Answer: D

3) Asexual reproduction occurs during _____. A) meiosis
B) mitosis
C) fertilization

D) chromosome exchange between organisms of different species

Answer: B

4) Quaking aspen can send out underground stems for asexual reproduction. Sexual reproduction is not as common, but when it does happen, the haploid gametes have 19 chromosomes. How many chromosomes are in the cells of the underground stems?
A) 9

B) 10
C) 19
D) 38

Answer: D

5) Which of the following is a true statement about sexual vs. asexual reproduction?
A) Asexual reproduction, but not sexual reproduction, is characteristic of plants and fungi.

B) In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring.
C) In asexual reproduction, offspring are produced by fertilization without meiosis.
D) Asexual reproduction produces only haploid offspring

Answer: B

6) At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype?
A) prophase
B) metaphase

C) anaphase
D) interphase

Answer: B

7) Which of the following is true of a species that has a chromosome number of 2n = 16?

A) The species is diploid with 32 chromosomes per cell.
B) The species has 16 sets of chromosomes per cell.
C) Each diploid cell has eight homologous pairs.

D) A gamete from this species has four chromosomes.

Answer: C

8) Eukaryotic sexual life cycles show tremendous variation. Of the following elements, which do all sexual life cycles have in common?
I. Alternation of generations
II. Meiosis

III. Fertilization
IV. Gametes
V. Spores
A) I, II, and IV
B) II, III, and IV
C) II, IV, and V
D) I, II, III, IV, and V

Answer: B

9) In a plant's sexual life cycle _____.
A) sporophytes produce gametes by meiosis
B) gametophytes produce gametes by mitosis
C) gametophytes produce gametes by meiosis
D) sporophytes produce gametes by mitosis

Answer: B

10) Which of the following is an example of alternation of generations?
A) A grandparent and grandchild each have dark hair, but the parent has blond hair.
B) A diploid plant (sporophyte) produces, by meiosis, a spore that gives rise to a multicellular, haploid pollen grain (gametophyte).
C) A diploid animal produces gametes by meiosis, and the gametes undergo fertilization to produce a diploid zygote.
D) A haploid mushroom produces gametes by mitosis, and the gametes undergo fertilization, which is immediately followed by meiosis.

Answer: B

11) A given organism has 46 chromosomes in its karyotype. Therefore, we can conclude that it must _____.
A) be human
B) be an animal

C) reproduce sexually
D) have gametes with 23 chromosomes

Answer: D

12) A triploid cell contains sets of three homologous chromosomes. If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have which of the following?

A) 63 chromosomes in 31.5 pairs

B) 63 chromosomes in 21 sets of 3
C) 63 chromosomes, each with three chromatids
D) 21 chromosome pairs and 21 unique chromosomes

Answer: B

13) Which of the following might result in a human zygote with 45 chromosomes? A) an error in either egg or sperm meiotic anaphase
B) failure of the egg nucleus to be fertilized by the sperm
C) failure of an egg to complete meiosis II

D) incomplete cytokinesis during spermatogenesis after meiosis I

Answer: A

14) In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common?
A) length and position of the centromere only

B) length, centromere position, and staining pattern only
C) length, centromere position, staining pattern, and traits coded for by their genes D) They have nothing in common except that they are X-shaped.

Answer: C

18) In a life cycle such as that shown in part III of the figure above, if the zygote's chromosome number is 10, which of the following will be true?
A) The sporophyte's chromosome number per cell is 10 and the gametophyte's is 5.
B) The sporophyte's chromosome number per cell is 5 and the gametophyte's is 10.

C) The sporophyte and gametophyte each have 10 chromosomes per cell.

D) The sporophyte and gametophyte each have 5 chromosomes per cell.

Answer: A

19) Homologous chromosomes _____.

A) are identical

B) carry information for the same traits

C) carry the same alleles

D) align on the metaphase plate in meiosis II

Answer: B

20) If meiosis produces haploid cells, how is the diploid number restored for those organisms that spend most of their life cycle in the diploid state?
A) DNA replication
B) reverse transcription

C) synapsis
D) fertilization

Answer: D

21) The human X and Y chromosomes _____.
A) are both present in every somatic cell of males and females

B) are the same size and have the same number of genes
C) include genes that determine an individual's sex
D) are called autosomes

Answer: C

22) Which of these is a karyotype?
A) a display of all of the cell types in an organism

B) organized images of a cell’s chromosomes
C) the appearance of an organism
D) a display of a cell’s mitotic stages

Answer: B

23) If a cell has completed meiosis I and is just beginning meiosis II, which of the following is an appropriate description of its contents?
A) It has half the amount of DNA as the cell that began meiosis.
B) It has half the chromosomes but twice the DNA of the originating cell.

C) It has one-fourth the DNA and one-half the chromosomes as the originating cell.

D) It is identical in content to another cell formed from the same meiosis I event.

Answer: A

24) The somatic cells of a privet shrub each contain 46 chromosomes. How do privet chromosomes differ from the chromosomes of humans ,who also have 46?
A) Privet cells cannot reproduce sexually.
B) Privet sex cells have chromosomes that can synapse with human chromosomes in the laboratory.

C) Genes of privet chromosomes are significantly different than those in humans.

D) Privet shrubs must be metabolically more like animals than like other shrubs.

Answer: C

25) After telophase I of meiosis, the chromosomal makeup of each daughter cell is _____.

A) diploid, and the chromosomes are each composed of a single chromatid
B) diploid, and the chromosomes are each composed of two chromatids
C) haploid, and the chromosomes are each composed of a single chromatid

D) haploid, and the chromosomes are each composed of two chromatids

Answer: D

26) How do cells at the completion of meiosis compare with cells that are in prophase of meiosis I? They have _____.
A) half the number of chromosomes and half the amount of DNA.
B) the same number of chromosomes and half the amount of DNA.

C) half the number of chromosomes and one-fourth the amount of DNA.

D) half the amount of cytoplasm and twice the amount of DNA.

Answer: C

27) Which of the following happens at the conclusion of meiosis I?

A) Homologous chromosomes of a pair are separated from each other.

B) The chromosome number per cell remains the same.
C) Sister chromatids are separated.
D) Four daughter cells are formed.

Answer: A

28) Sister chromatids separate from each other during _____.

A) meiosis I only
B) meiosis II only
C) mitosis and meiosis I

D) mitosis and meiosis II

Answer: D

29) Which of the following occurs in meiosis but not in mitosis?

A) chromosome replication
B) synapsis of chromosomes
C) alignment of chromosomes at the equator

D) condensation of chromosomes

Answer: B

30) When we first see chiasmata under a microscope, we know that _____.

A) meiosis II has occurred
B) anaphase II has occurred
C) prophase I is occurring

D) separation of homologs has occurred

Answer: C

For the following questions, match the key event of meiosis with the stages listed below.

I. Prophase I II.Metaphase I

III. Anaphase I IV. TelophaseI

V. Prophase II VI. Metaphase II

VII. Anaphase II VIII.TelophaseII

31) Homologous chromosomes are aligned at the equator of the spindle.

A) I
B) II
C) IV

D) VI

Answer: B

For the following questions, match the key event of meiosis with the stages listed below.

I. Prophase I II.Metaphase I

III. Anaphase I IV. TelophaseI

V. Prophase II VI. Metaphase II

VII. Anaphase II VIII.TelophaseII

32) Centromeres of sister chromatids disjoin and chromatids separate.

A) III
B) IV
C) V

D) VII

Answer: D

38) A certain female's number 12 chromosomes both have the blue gene and number 19 chromosomes both have the long gene. As cells in her ovaries undergo meiosis, her resulting eggs (ova) may have which of the following?
A) either two number 12 chromosomes with blue genes or two with orange genes

B) either two number 19 chromosomes with long genes or two with short genes
C) either one blue or one orange gene in addition to either one long or one short gene

D) one chromosome 12 with one blue gene and one chromosome 19 with one long gene

Answer: D

39) 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?
A) only blue short gene eggs

B) only orange short gene eggs
C) one-half blue short and one-half orange short gene eggs
D) three-fourths blue short and one-fourth orange short gene eggs

Answer: C

40) A female with a paternal set of one orange and one long gene chromosome and a maternal set comprised of one blue and one short gene chromosome is expected to produce which of the following types of eggs after meiosis?
A) All eggs will have maternal types of gene combinations.

B) All eggs will have paternal types of gene combinations.
C) Half the eggs will have maternal and half will have paternal combinations.
D) Each egg has a one-fourth chance of having either blue long, blue short, orange long, or orange short combinations.

Answer: D

41) Somatic cells of roundworms have four individual chromosomes per cell. How many chromosomes would you expect to find in an ovum from a roundworm?
A) four
B) two

C) eight
D) a diploid number

Answer: B

42) Which of the following can occur by the process of meiosis but not mitosis?

A) Haploid cells fuse to form diploid cells.
B) Haploid cells multiply into more haploid cells.
C) Diploid cells form haploid cells.

D) A diploid cell combines with a haploid cell.

Answer: C

43) In meiosis, homologous chromosomes are separated during _____.

A) anaphase II
B) prophase I
C) mitosis

D) anaphase I

Answer: D

44) What is a major difference between meiosis II and mitosis in a diploid animal?

A) Homologues align on the metaphase plate in meiosis II.
B) Sister chromatids separate in mitosis, and homologues separate in meiosis II.

C) Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells.

D) Crossover takes place in meiosis II.

Answer: C

45) What is a major difference between mitosis and meiosis I in a diploid organism?
A) Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis I.
B) Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis II.
C) DNA replication takes place prior to mitosis, but not before meiosis I.
D) Only meiosis I results in daughter cells that contain identical genetic information.

Answer: A

46) Crossing over normally takes place during which of the following processes?

A) meiosis II
B) meiosis I
C) mitosis

D) mitosis and meiosis II

Answer: B

47) For the duration of meiosis I, each chromosome _____.

A) is paired with a homologous chromosome
B) consists of two sister chromatids joined by a centromere

C) consists of a single strand of DNA

D) is joined with its homologous pair to form a synaptonemal complex

Answer: B

48) Homologous pairs of chromosomes align opposite of each other at the equator of a cell during _____.
A) mitosis metaphase
B) meiosis metaphase I

C) meiosis telophase II
D) meiosis metaphase II

Answer: B

49) Centromeres split and sister chromatids migrate to opposite poles in meiosis _____.

A) anaphase I
B) telophase I
C) anaphase II

D) telophase II

Answer: C

50) Quaking aspen can send out underground stems for asexual reproduction. Sexual reproduction is not as common, but when it does happen, the haploid gametes have 19 chromosomes. How many chromosomes are in the cells of the underground stems?

A) 9

B) 10
C) 19
D) 38

Answer: D

51) Independent assortment of chromosomes occurs during _____

A) meiosis I only
B) meiosis II only
C) mitosis and meiosis I

D) mitosis and meiosis II

Answer: A

52) For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes?
A) 23
B) 46

C) about 1000
D) about 8 million

Answer: D

53) Independent assortment of chromosomes is a result of _____.
A) the random way each pair of homologous chromosomes lines up at the metaphase plate during meiosis I
B) the random combinations of eggs and sperm during fertilization
C) the random distribution of the sister chromatids to the two daughter cells during anaphase II

D) the diverse combination of alleles that may be found within any given chromosome

Answer: A

54) When homologous chromosomes cross over, what occurs?
A) Two chromatids get tangled, resulting in one re-sequencing its DNA.
B) Two sister chromatids exchange identical pieces of DNA.
C) Corresponding segments of non-sister chromatids are exchanged.
D) Maternal alleles are "corrected" to be like paternal alleles and vice versa.

Answer: C

55) How is natural selection related to sexual reproduction as opposed to asexual reproduction?

A) Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction.
B) Sexual reproduction results in the greatest number of new mutations.

C) Sexual reproduction allows the greatest number of offspring to be produced.

D) Sexual reproduction utilizes far less energy than asexual reproduction.

Answer: A

56) The diploid number of a roundworm species is 4. Assuming there is no crossover, and random segregation of homologues during meiosis, how many different possible combinations of chromosomes might there be in the offspring (not including variety generated by crossing over)?

A) 4
B) 8
C) 16
D) 64

Answer: C

57) The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. Diversity in this species may be generated by mutations and _____.
A) crossing over

B) independent assortment
C) crossing over and independent assortment D) nothing else

Answer: C

58) The fastest way for organisms to adapt to a changing environment involves _____.

A) mutation
B) asexual reproduction
C) sexual reproduction

Answer: C

59) Imagine that there are twenty-five different species of protists living in a tide pool. Some of these species reproduce both sexually and asexually, and some of them can reproduce only asexually. The pool gradually becomes infested with disease-causing viruses and bacteria. Which species are more likely to thrive in the changing environment?

A) the sexually reproducing species
B) the asexually reproducing species
C) Sexually and asexually reproducing species are equally likely to thrive.

Answer: A

60) In eukaryotes, genetic information is passed to the next generation by processes that include mitosis or meiosis. Which of the explanations identifies the correct process and supports the claim that heritable information is passed from one generation to another?
A) During mitosis, DNA replication occurs twice within the cell cycle to insure a full set of chromosomes within each of the daughter cells produced.

B) Mitosis, followed by cytokinesis, produces daughter cells that are genetically different from the parent cell, thus insuring variation within the population.
C) In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes.

D) Single-celled organisms can fuse their cells, reproducing asexually through mitosis to form new cells that are not identical to the parent cell.

Answer: C

61) Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Biological systems have multiple processes, such as reproduction, that affect genetic variation. They are evolutionarily conserved and shared by various organisms.

Which statement best represents the connection between reproduction and evolution?
A) Plants that use sexual reproduction are rare since this type of reproduction in plants does not contribute to genetic diversity.
B) In order to increase genetic diversity for evolution in sexually reproducing organisms, mutations must occur in the zygote after fertilization.
C) Since prokaryotic organisms reproduce asexually, there is no mechanism for them to add genetic diversity for evolution.
D) Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.

Answer: D