Chapter 10
In a diploid cell containing 10 chromosomes, meiosis results in the formation of daughter cells containing _____ chromosomes. ( Concept 10.2) 5 10 20 40 0
a
In humans, the haploid number of chromosomes is 23. Independent assortment has the possibility of producing _____ different types of gametes. ( Concept 10.4) 2^23 1 million 223 24 100,000
a
In sexually reproducing species, the chromosome number remains stable over time because _____ and _____ always alternate. ( Concept 10.2) meiosis ... fertilization meiosis ... mitosis mitosis ... fertilization meiosis ... interphase meiosis I ... meiosis II
a
The synaptonemal complex _____. ( Concept 10.3) physically connects homologous chromosomes during prophase I physically connects homologous chromosomes during mitosis is broken down by enzymes during anaphase II is another name for chiasmata is formed by a protein called cohesin
a
What is a locus? ( Concept 10.1) the precise location of a gene on a chromosome a structure that appears during prophase I and consists of two paired genes the precise DNA sequence of a gene a type of spore made only by fungi a cell with two chromosome sets
a
Which of the following occurs during anaphase I? ( Concept 10.3) Homologs separate and migrate toward opposite poles. Sister chromatids separate and migrate toward opposite poles. Nuclei re-form. Chromosomes line up in one plane. The cell is haploid.
a
Homologous chromosomes move toward opposite poles of a dividing cell during meiosis II. meiosis I. binary fission fertilization. mitosis
b
How many pairs of autosomes do humans have? ( Concept 10.2) 23 22 2 1 It depends on the sex of the individual.
b
In a diploid set of chromosomes, one member of each pair of homologous chromosomes is derived from the father (paternal), and the other comes from the mother (maternal). If 2n = 6, what is the probability of obtaining a gamete in which all the chromosomes are paternal ones? ( Concept 10.4) 1/4 1/8 1/16 1/32 The answer cannot be determined from these data.
b
Regarding the role of cohesin protein in maintaining cohesion between sister chromatids, which of the following statements is false?( Concept 10.3) During meiosis I, cohesion holds sister chromatids together along their lengths as chiasmata form between homologs. During meiosis II, cohesion holds sister chromatids along their lengths as the second meiotic spindle forms. Cleavage of cohesins between sister chromatid arms at anaphase I allows homologs to separate. The first and second listed responses are false. The second and third listed responses are false. None of the listed responses is false.
b
Synapsis occurs during _____. ( Concept 10.3) anaphase I prophase I cytokinesis prophase II metaphase I
b
The major contribution of sex to evolution is that _____. ( Concept 10.4) it is the only mechanism for species to reproduce it provides a method to increase genetic variation it provides a way in which somatic mutations can be inherited The first and second listed responses are correct. The second and third listed responses are correct.
b
Which event occurs only during prophase I of the first meiotic division? ( Concept 10.3) Homologous chromosomes line up at the center of the cell. Synapsis of homologous pairs occurs. The nuclear membrane breaks down. Replication of DNA takes place. A spindle of microtubules forms.
b
Which of the following occurs during anaphase II? ( Concept 10.3) Homologs separate and migrate toward opposite poles. Sister chromatids separate and migrate toward opposite poles. Nuclei re-form. Chromosomes line up in one plane. The synaptonemal complex disappears.
b
Fertilization produces _____. ( Concept 10.2) a haploid zygote in some life cycles and a diploid zygote in others a haploid zygote a diploid zygote a diploid zygote, except during the gametophyte stage of alternation of generations a multicellular haploid organism in a life cycle with an alternation of generations
c
If we continued to follow the cell lineage from question 3, then the DNA content of a single cell at metaphase of meiosis II would be 0.25x. 0.5x. x. 2x. 4x
c
In a male mammal, every cell that undergoes meiosis gives rise to _____ sperm. ( Concept 10.3) one two four no set number zero
c
Sister chromatids _____. ( Concept 10.2) are only involved in mitosis are pairs of chromosomes, one of which comes from the father and one of which comes from the mother are identical copies of each other formed during DNA synthesis have the same gene loci but may have different alleles of some genes are only involved in meiosis
c
Spores and gametes are different in that _____. ( Concept 10.2) gametes never resemble spores morphologically gametes are always haploid whereas spores are diploid gametes can fuse to form a zygote, but spores can develop into independent organisms without first forming a zygote only the formation of gametes contributes to genetic variation gametes are derived directly from sporophytes to form gametophytes
c
The egg (ovum) of a rabbit contains 22 chromosomes. How many chromosomes are in the somatic (body) cells of a rabbit? ( Concept 10.2) 11 22 44 88 132
c
When we say that an organism is haploid, we mean that _____. ( Concept 10.2) its cells each have one chromosome it has one half of a chromosome its cells have a single set of chromosomes its cells have two sets of chromosomes its cells have half of one set of chromosomes
c
Which of the following answers is not involved nor an outcome of crossing over? ( Concept 10.4) The DNA in two nonsister chromatids is broken by specific proteins at exact points. Chiasmata indicate where crossing over is occurring between homologs. the random alignment of homologous pairs of chromosome at metaphase I formation of chromosomes containing paternal and maternal alleles All of the listed responses pertain to the process of crossing over.
c
Which of the following results in cells that contain half the parental chromosome number? ( Concept 10.3) cytokinesis mitosis meiosis interphase metaphase
c
Which of the following statements reflects an advantage that sexual reproduction likely provides over asexual reproduction? ( Concept 10.4) In terms of energetic costs, sexual reproduction is a cheaper strategy than asexual reproduction for generating genetic variation in a population. Although sexual and asexual reproduction both offer opportunities for increasing genetic variation, sexual reproduction is comparatively lower in its energetic costs to the organism. Although energetically more costly than asexual reproduction, sexual reproduction leads to different combinations of alleles that could provide adaptability in a changing environment. Sexual reproduction maintains the same combination of alleles and does not run the risk of losing successful combination of alleles as is observed to occur in asexually reproducing organisms. Although both reproductive strategies perpetuate the same combination of alleles within individuals in a population, sexual reproduction is energetically less costly than asexual reproduction.
c
A human cell containing 22 autosomes and a Y chromosome is a somatic cell of a female. a somatic cell of a male. a zygote. a sperm. an egg.
d
A karyotype is _____. ( Concept 10.2) the physical traits a person has a method of identifying crossover events all the possible gametes a person could produce a photograph of all of an individual's chromosomes a list of all the genes a person carries
d
Although _____ is nearly universal among animals, bdelloid rotifers _____. ( Concept 10.4) asexual production ... have achieved great diversity by using sexual reproduction sexual reproduction ... reproduce asexually and achieve genetic diversity by mutations alone sexual production ... reproduce asexually because they inhabit very stable environments and the production of gametes would be an inefficient use of energy sexual reproduction ... reproduce asexually but can increase genetic variation present in a population by means of the uptake of DNA from other rotifers
d
How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n = 8)? 2 4 8 16 32
d
How many genes are present in the human genome? ( Concept 10.1) 23 46 hundreds tens of thousands a virtually infinite number
d
Humans have 46 chromosomes. This number of chromosomes will be found in _____. ( Concept 10.2) all cells in anaphase of mitosis all the egg and sperm cells all gamete-producing cells after meiosis I liver cells all the cells of the body
d
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 0.25x. 0.5x. x. 2x. 4x.
d
Ignoring crossover, how many kinds of gametes can be produced by an organism with a diploid number of 8? ( Concept 10.4) 2 4 8 16 32
d
Nearly all life cycles have both haploid and diploid phases. Usually, the transition from haploid to diploid takes place _____. ( Concept 10.2) during crossing over in meiosis when DNA is replicated during the S phase of the cell cycle when mitotic cytokinesis occurs at fertilization, when gametes fuse during gastrulation
d
Regions of chromosomes where nonsister chromatids cross over are called _____. ( Concept 10.3) inversions homologs kinetochores chiasmata tetrads
d
Sexual and asexual reproduction are alike in that _____. ( Concept 10.1) they both give rise to genetically distinct offspring they both involve two parents they both require meiosis to complete the reproductive cycle they can both occur in multicellular organisms in both cases, every parent transmits all of its genes to its progeny
d
Somatic cells in humans contain _____ set(s) of chromosomes and are therefore termed _____. (Concept 10.2) one ... diploid two ... haploid one ... haploid two ... diploid three ... triploid
d
Unless the chromosomes were stained to show band patterns, a karyotype would be least likely to show which of the following? ( Concept 10.2) an extra chromosome a large part of a chromosome duplicated a missing chromosome part of a chromosome turned around the attachment of a large part of a chromosome to another chromosome
d
What is the function of meiosis? ( Concept 10.3) to make exact copies of the parent cell to make one cell with twice the number of chromosomes as the parent pairs to make four cells with the same chromosome number as the parent to make cells with a haploid (half that of the parents) number of chromosomes to make diploid spores
d
What is the result when a diploid cell undergoes meiosis? ( Concept 10.3) two diploid cells two haploid cells four diploid cells four haploid cells two haploid cells and two diploid cells
d
Which of the following contributes to genetic variation in sexually reproducing species? ( Concept 10.4) crossing over, internal fertilization, independent assortment independent assortment, spindle formation, random fertilization random fertilization, DNA synthesis, independent assortment random fertilization, independent assortment, crossing over internal fertilization, spindle formation, crossing over
d
Which of the following is a function of mitosis in humans? ( Concept 10.2) production of eggs production of sperm decreasing the number of chromosomes multiplication of body cells increasing genetic variability
d
A clone is the product of _____. ( Concept 10.1) asexual reproduction sexual reproduction mitosis meiosis The first and third listed responses are correct. The second and fourth listed responses are correct.
e
At the end of telophase I of meiosis and the first cytokinesis, there are _____. ( Concept 10.3) four haploid cells two diploid cells four diploid cells one haploid ovum and three polar bodies two haploid cells
e
Crossing over occurs during _____. ( Concept 10.3) cytokinesis metaphase I prophase II metaphase II prophase I
e
The diploid number of chromosomes in a certain animal is 8 (2n = 8). How do the four pairs of homologous chromosomes align and separate during meiosis? ( Concept 10.4) All of the maternal chromosomes always move to one pole, and all the paternal chromosomes always move to the other pole. All 16 chromatids move together. Exactly two maternal and two paternal chromosomes always move to each of the two poles. The first to move influences all the others. They align and assort independently to form any of 16 different combinations.
e
The sexual cycle of the multicellular algal genus Fucus involves _____. ( Concept 10.2) mitosis only both mitosis and meiosis but not fertilization both mitosis and fertilization but not meiosis only meiosis and fertilization mitosis, meiosis, and fertilization
e
Which function makes meiosis lengthier and more complex than mitosis? ( Concept 10.3) decreasing the chromosome number to haploid introducing genetic variation among the daughter cells ensuring that each daughter cell gets a single, complete set of chromosomes undergoing two rounds of cytokinesis all of the above
e
Which of the following is part of the life cycle called alternation of generations? ( Concept 10.2) multicellular haploid stage (gametophyte) multicellular diploid stage (sporophyte) zygote spores all of the above
e
Which, if any, of the following statements is true? ( Concept 10.2) Diploid cells can divide by mitosis. Diploid cells can divide by meiosis. Haploid cells can divide by mitosis. Haploid cells cannot divide by meiosis. All of the above responses are correct.
e
