Biology Chapter 13

What number and types of chromosomes are found in a human somatic cell? A) 45 autosomes and 1 sex chromosome B) n chromosomes C) 44 autosomes and 2 sex chromosomes D) 22 autosomes and 1 sex chromosome E) 21 autosomes and 2 sex chromosomes

44 autosomes and 2 sex chromosomes

A triploid cell contains three sets of 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 21 sets of 3 B) 63 chromosomes in 31 1/2 pairs C) 21 chromosome pairs and 21 unique chromosomes D) 63 chromosomes, each with three chromatids

63 chromosomes in 21 sets of 3

Which of these statements is false? A) In humans, the 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY). B) Single, haploid (n) sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote. C) Sexual life cycles differ with respect to the relative timing of meiosis and fertilization. D) At sexual maturity, ovaries and testes produce diploid gametes by meiosis. E) In humans, each of the 22 maternal autosomes has a homologous paternal chromosome.

At sexual maturity, ovaries and testes produce diploid gametes by meiosis

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) Clone the plant asexually to produce an identical one. B) Add nitrogen to the soil of the offspring of this plant so the desired traits continue. C) Force the plant to self-pollinate to obtain an identical one. D) Breed this plant with another plant with much weaker traits. E) Backtrack through her previous experiments to obtain another plant with the same traits.

Clone the plant asexually to produce an identical one

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) Each cell has eight homologous pairs. C) During the S phase of the cell cycle there will be 32 separate chromosomes. D) The species has 16 sets of chromosomes per cell. E) A gamete from this species has four chromosomes.

Each cell has eight homologous pairs

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) Sister chromatids are only formed during mitosis. Homologous chromosomes are formed during meiosis. C) Homologous chromosomes are identical copies of each other. One sister chromatid comes from the father, and one comes from the mother. D) Homologous chromosomes are closely associated with each other in both mitosis and meiosis. Sister chromatids are only associated with each other during mitosis. E) 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.

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

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 asexual reproduction, offspring are produced by fertilization without meiosis. C) In sexual reproduction, individuals transmit 50% of their genes to each of their offspring. D) Asexual reproduction produces only haploid offspring. E) Sexual reproduction requires that parents be diploid.

In sexual reproduction, individuals transmit 50% of their genes to each of their offspring

A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following? A) It must be human. B) Its gametes must have 23 chromosomes. C) It must be sexually reproducing. D) It must be a primate. E) It must be an animal.

Its gametes must have 23 chromosomes

When homologous chromosomes cross over, what occurs? A) Each of the four DNA strands of a homologous pair is broken, and the pieces are mixed. B) Two sister chromatids exchange identical pieces of DNA. C) Specific proteins break the two strands of nonsister chromatids and re-join them. D) Two chromatids get tangled, resulting in one re-sequencing its DNA. E) Maternal alleles are "corrected" to be like paternal alleles and vice versa.

Specific proteins break the two strands of nonsister chromatids and re-join them

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

Synapsis occurs

For what purpose(s) might a karyotype be prepared? Choose the best answer. A) for prenatal screening, to determine if a fetus has the correct number of chromosomes B) to determine whether a fetus is male or female C) to detect the possible presence of chromosomal abnormalities such as deletions, inversions, or translocations D) The first and second answers are correct. E) The first three answers are correct.

The first three answers are correct

Independent assortment of chromosomes occurs. A) The statement is true for mitosis and meiosis I. B) The statement is true for meiosis II only. C) The statement is true for mitosis only. D) The statement is true for mitosis and meiosis II. E) The statement is true for meiosis I only.

The statement is true for meiosis I only

Which of the following best describes a karyotype? A) a photograph of all the cells with missing or extra chromosomes B) the combination of all the maternal and paternal chromosomes of a species C) a pictorial representation of all the genes for a species D) the collection of all the chromosomes in an individual organism E) a display of each of the chromosomes of a single cell

a display of each of the chromosomes of a single cell

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

a sperm

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 8 million D) 920 E) 460

about 8 million

The human X and Y chromosomes A) are called autosomes. B) include genes that determine an individual's sex. C) are both present in every somatic cell of males and females alike. D) are almost entirely homologous, despite their different names. E) are about the same size and have approximately the same number of genes.

include genes that determine an individual's sex

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

meiosis

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

meiosis I

Which is the smallest unit containing the entire human genome? A) one human somatic cell B) one human chromosome C) one human gene D) the entire human population E) all of the DNA of one human

one human somatic cell

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

produces offspring genetically identical to the parent

Meiosis II is similar to mitosis in that A) homologous chromosomes synapse. B) the chromosome number is reduced. C) the daughter cells are diploid. D) sister chromatids separate during anaphase. E) DNA replicates before the division.

sister chromatids separate during anaphase

Which of the following defines a genome? A) the complete set of a species' polypeptides B) representation of a complete set of a cell's polypeptides C) a karyotype D) the complete set of an organism's polypeptides E) the complete set of an organism's genes

the complete set of an organism's genes

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

the exchange of homologous portions of nonsister chromatids

Independent assortment of chromosomes is a result of A) the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I. B) the random nature of the fertilization of ova by sperm. C) the relatively small degree of homology shared by the X and Y chromosomes. D) the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I, the random nature of the fertilization of ova by sperm, the random distribution of the sister chromatids to the two daughter cells during anaphase II, and the relatively small degree of homology shared by the X and Y chromosomes. E) the random distribution of the sister chromatids to the two daughter cells during anaphase II.

the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I

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 haploid cells ... two diploid cells C) four diploid cells ... four haploid cells D) two diploid cells ... two haploid cells E) two diploid cells ... four haploid cells

two diploid cells ... four haploid cells