BIo CH 13

The egg (ovum) of a rabbit contains 22 chromosomes. How many chromosomes are in the somatic (body) cells of a rabbit? 132 44 22

44

__________ are a group of genetically identical individuals produced by a process called __________. Gametes; meiosis Gametes; asexual reproduction Clones; asexual reproduction

Clones; asexual reproduction

What is the result when a diploid cell undergoes meiosis? Two haploid cells and two diploid cells Four haploid cells Two haploid cells

Four haploid cells

Which life cycle stage is found in plants but not animals? Unicellular diploid Multicellular haploid Zygote

Multicellular haploid

Which of the following is a function of mitosis in humans? Increasing genetic variability Multiplication of body cells Production of eggs

Multiplication of body cells

Which of the following statements about homologous chromosomes is correct? They are found in the cells of human females but not in human males. They are found in animal cells but not in plant cells. They have genes for the same traits at the same loci.

They have genes for the same traits at the same loci.

Somatic cells in animals differ from gametes in that somatic cells __________. do not contain sex chromosomes are all of the cells of the body except for the gametes and their precursors are always haploid

are all of the cells of the body except for the gametes and their precursors

Somatic cells in humans differs from gametes in that human somatic cells __________. do not contain sex chromosomes contain two sets of each of the 23 chromosome types are important in sexual reproduction

contain two sets of each of the 23 chromosome types

Allelic variation is an important source of __________ in a population. asexual reproduction clonal diversity genetic diversity

genetic diversity

A pair of genetic structures carrying genes that control the same inherited characters are called __________. clones zygotes homologous chromosomes

homologous chromosomes

The process called __________ reduces the chromosome number by __________. mitosis; two consecutive cell divisions meiosis; two consecutive cell divisions mitosis; destroying one set of information prior to division

meiosis; two consecutive cell divisions

Genetic diversity requires __________. sexual reproduction, independent assortment, crossing over between nonsister chromatids of homologous chromosomes, and random fertilization sexual reproduction, nonindependent assortment, crossing over between nonsister chromatids of homologous chromosomes, and random fertilization asexual reproduction, independent assortment, crossing over between sister chromatids of homologous chromosomes, and random fertilization

sexual reproduction, independent assortment, crossing over between nonsister chromatids of homologous chromosomes, and random fertilization

Somatic cells in humans contain __________ set(s) of chromosomes and are therefore termed __________. one; haploid two; diploid three; triploid

two; diploid

Which of the following occurs in meiosis, but not mitosis? The cells formed have the same combination of genes as found in the initial cell. Homologous chromosomes separate. The nuclear envelope disappears.

Homologous chromosomes separate.

How many genes are present in the human genome?

Tens of thousands

What is a locus? A type of spore made only by fungi. The precise location of a gene on a chromosome. A cell with two chromosome sets.

The precise location of a gene on a chromosome.

The life cycle called __________ in plants has two multicellular stages: the __________ and the __________. reduction division; diploid gametophyte; haploid sporophyte reduction division; haploid gametophyte; diploid sporophyte alternation of generations; haploid gametophyte; diploid sporophyte

alternation of generations; haploid gametophyte; diploid sporophyte

Sister chromatids differ from nonsister chromatids in that sister chromatids __________. are products of the S phase of the cell cycle and are two copies of one chromosome always come from nonsister chromatids are part of nonhomologous chromosomal sets

are products of the S phase of the cell cycle and are two copies of one chromosome

A clone is the product of __________. sexual reproduction asexual reproduction and mitosis meiosis

asexual reproduction and mitosis

Regardless of whether an organism is an animal, a plant, a fungus, or an algal cell, all zygotes are __________ and are formed during the __________ of two __________ gametes. diploid; fertilization; haploid clones; meiotic division; diploid None of the listed responses is correct because only animals have zygotes.

diploid; fertilization; haploid

The major contribution of sex to evolution is that __________. it provides a method to increase genetic variation it is the only mechanism for species to reproduce it provides a way in which somatic mutations can be inherited

it provides a method to increase genetic variation

In meiosis, __________ of __________ cross over and form __________. sister chromatids; homologous pairs; chiasmata nonsister chromatids; homologous pairs; chiasmata sister chromatids; nonhomologous pairs; chiasmata

nonsister chromatids; homologous pairs; chiasmata

At the end of mitosis, __________ daughter cells that are genetically __________ are formed, while at the end of meiosis, __________ daughter cells that are genetically __________ are formed. four; distinct; two; identical two; distinct; four; identical two; identical; four; distinct

two; identical; four; distinct