BIOL105 Chapter 10 HW
What is the result when a diploid cell undergoes meiosis? two haploid cells and two diploid cells four haploid cells two haploid cells four diploid cells
four haploid cells
In animals, fertilization is to zygote as meiosis is to which of the following? chromosome gamete mitosis replication
gamete
Which of the following transmits genes from both parents to child, or from one generation of a family to another? mitosis gametes nucleotides DNA
gametes
Humans have 46 chromosomes. This number of chromosomes will be found in __________. all the egg and sperm cells all the cells of the body liver cells all cells in anaphase of mitosis
liver cells
Which of the following results in cells that contain half the parental chromosome number? cytokinesis metaphase meiosis mitosis
meiosis
In sexually reproducing species, the chromosome number remains stable over time because __________ and __________ always alternate. meiosis ... fertilization mitosis ... fertilization meiosis ... interphase meiosis ... mitosis
meiosis ... fertilization
At what stage is the independent assortment of chromosomes determined? prophase I pairing of homologs anaphase II separation of homologs metaphase I alignment of paired homologs telophase I
metaphase I alignment of paired homologs
The sexual cycle of the multicellular algal genus Fucus involves __________ mitosis only mitosis, meiosis, and fertilization only meiosis and fertilization both mitosis and meiosis but not fertilization
mitosis, meiosis, and fertilization
Which of the following is a function of mitosis in humans? multiplication of body cells that are genetically identical to the parent cell production of eggs decreasing the number of chromosomes increasing genetic variability
multiplication of body cells that are genetically identical to the parent cell
The synaptonemal complex __________. physically connects homologous chromosomes during mitosis physically connects homologous chromosomes during prophase I is formed by a protein called cohesion is broken down by enzymes during anaphase II
physically connects homologous chromosomes during prophase I
Crossing over occurs during __________. metaphase I metaphase II prophase I prophase II
prophase I
Synapsis occurs during __________. prophase II prophase I anaphase I metaphase I
prophase I
Which of the following contributes to genetic variation in sexually reproducing species? random fertilization, independent assortment, crossing over crossing over, internal fertilization, independent assortment internal fertilization, spindle formation, crossing over independent assortment, spindle formation, random fertilization
random fertilization, independent assortment, crossing over
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? 1/8 1/4 1/16 1/32
1/8
Which of following occurs during anaphase II? Chromosomes line up in one plane. Nuclei re-form. Sister chromatids separate and migrate toward opposite poles. Homologs separate and migrate toward opposite poles.
Sister chromatids separate and migrate toward opposite poles.
Which event occurs only during prophase I of the first meiotic division? Synapsis of homologous pairs occurs. Replication of DNA takes place. A spindle of microtubules forms. Homologous chromosomes line up at the center of the cell.
Synapsis of homologous pairs occurs.
A karyotype is __________. a list of all the genes a person carries a display of all of an individual's chromosomes arranged in pairs a method of identifying crossover events all the possible gametes a person could produce
a display of all of an individual's chromosomes arranged in pairs
Nearly all life cycles have both haploid and diploid phases. Usually, the transition from haploid to diploid takes place __________. when mitotic cytokinesis occurs during crossing over in meiosis when DNA is replicated during the S phase of the cell cycle at fertilization, when gametes fuse
at fertilization, when gametes fuse
Regarding the role of cohesin protein in maintaining cohesion between sister chromatids, which of the following statements is FALSE? Cleavage of cohesins between sister chromatid arms at anaphase I allows homologs to separate. 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. None of the listed responses is false.
During meiosis II, cohesion holds sister chromatids along their lengths as the second meiotic spindle forms.
Ignoring crossover, how many kinds of gametes can be produced by an organism with a diploid number of 8? 64 8 16 32
16
How many pairs of autosomes do humans have? 2 23 22 1
22
In humans, the haploid number of chromosomes is 23. Independent assortment has the possibility of producing __________ different types of gametes. 1 million 23^2 24 2^23
2^23
In a male mammal, every cell that undergoes meiosis gives rise to __________ sperm. 2 0 4 1
4
The egg (ovum) of a rabbit contains 22 chromosomes. How many chromosomes are in the somatic (body) cells of a rabbit? 22 11 88 44
44
In a diploid cell containing 10 chromosomes, meiosis results in the formation of daughter cells containing __________ chromosomes. 20 20 40 5
5
Which function makes meiosis lengthier and more complex than mitosis? undergoing two rounds of cytokinesis All of the listed responses are correct. ensuring that each daughter cell gets a single, complete set of chromosomes introducing genetic variation among the daughter cells
All of the listed responses are correct.
Which of the following is part of the life cycle called alternation of generations? All of the listed responses are correct. zygote multicellular diploid stage (sporophyte) multicellular haploid stage (gametophyte
All of the listed responses are correct.
Which, if any, of the following statements is true? Diploid cells can divide by mitosis. All of the listed responses are correct. Haploid cells cannot divide by meiosis. Diploid cells can divide by meiosis.
All of the listed responses are correct.
Which of the following statements reflects an advantage that sexual reproduction likely provides over asexual reproduction? Although both reproductive strategies perpetuate the same combination of alleles within individuals in a population, sexual reproduction is energetically less costly than asexual reproduction. 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 energetically more costly than asexual reproduction, sexual reproduction leads to different combinations of alleles that could provide adaptability in a changing environment
A clone is the product of __________. Asexual reproduction Meiosis Asexual reproduction & meiosis Asexual reproduction & mitosis
Asexual reproduction & mitosis
Which of the following occurs during anaphase I? Chromosomes line up in one plane. Sister chromatids separate and migrate toward opposite poles. Nuclei re-form. Homologs separate and migrate toward opposite poles, guided by the spindle apparatus.
Homologs separate and migrate toward opposite poles, guided by the spindle apparatus
What is the main advantage of sexual reproduction over asexual reproduction? It increases genetic variation among offspring. It is more efficient at producing offspring. Two parents can invest resources in offspring. It allows for more competition.
It increases genetic variation among offspring.
Privet shrubs and humans each have a diploid number of 46 chromosomes per cell. Why are the two species so dissimilar? The two species have appreciably different genes. Privet chromosomes undergo only mitosis. Privet chromosomes are shaped differently. Human chromosomes have genes grouped together differently.
The two species have appreciably different genes.
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? Exactly two maternal and two paternal chromosomes always move to each of the two poles. All 16 chromatids move together. All of the maternal chromosomes always move to one pole, and all the paternal chromosomes always move to the other pole. They align and assort independently to form any of 16 different combinations.
They align and assort independently to form any of 16 different combinations.
Fertilization produces __________. a diploid zygote a haploid zygote in some life cycles and a diploid zygote in others a diploid zygote, except during the gametophyte stage of alternation of generations a haploid zygote
a diploid zygote
Sister chromatids __________. are pairs of chromosomes, one of which comes from the father and one of which comes from the mother are only involved in mitosis are identical copies of each other formed during DNA synthesis have the same gene loci but may have different alleles of some genes
are identical copies of each other formed during DNA synthesis
Regions of chromosomes where nonsister chromatids cross over are called __________. chiasmata inversions kinetochores tetrads
chiasmata
Spores and gametes are different in that __________ gametes never resemble spores morphologically gametes are derived directly from sporophytes to form gametophytes 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 can fuse to form a zygote, but spores can develop into independent organisms without first forming a zygote
The major contribution of sex to evolution is that __________. a way in which somatic mutations can be inherited it is the only mechanism for species to reproduce it increases genetic variation All options are correct.
it increases genetic variation
When we say that an organism is haploid, we mean that __________. its cells have half of one set of chromosomes its cells each have one chromosome its cells have a single set of chromosomes it has one half of a chromosome
its cells have a single set of chromosomes
What allows sister chromatids to separate in which phase of meiosis? release of cohesin at centromeres in anaphase II release of cohesin at centromeres in anaphase I crossing over of chromatids in prophase I release of cohesin along sister chromatid arms in anaphase I
release of cohesin at centromeres in anaphase II
Although __________ is nearly universal among animals, bdelloid rotifers __________. 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 asexual production ... have achieved great diversity by using sexual reproduction sexual reproduction ... reproduce asexually and achieve genetic diversity by mutations alone
sexual reproduction ... reproduce asexually but can increase genetic variation present in a population by means of the uptake of DNA from other rotifers
How many genes are present in the human genome? tens of thousands hundreds 23 46
tens of thousands
Which of the following answers is NOT involved with or an outcome of crossing over? Chiasmata indicate where crossing over is occurring between homologs. formation of chromosomes containing paternal and maternal alleles The DNA in two nonsister chromatids is broken by specific proteins at exact points. the random alignment of homologous pairs of chromosome at metaphase I
the random alignment of homologous pairs of chromosome at metaphase I
What is a locus? a cell with two chromosome sets a structure that appears during prophase I and consists of two paired genes the precise DNA sequence of a gene the specific location of a gene along the length of a chromosome
the specific location of a gene along the length of a chromosome
Sexual and asexual reproduction are alike in that __________. in both cases, every parent transmits all of its genes to its progeny they both involve two parents they can both occur in multicellular organisms they both require meiosis to complete the reproductive cycle
they can both occur in multicellular organisms
What is the function of meiosis? 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 exact copies of the parent cell to make one cell with twice the number of chromosomes as the parent pairs
to make cells with a haploid (half that of the parents) number of chromosomes
Somatic cells in humans contain __________ set(s) of chromosomes and are therefore termed __________. two ... haploid one ... haploid one ... diploid two ... diploid
two ... diploid
At the end of telophase I of meiosis and the first cytokinesis, there are __________. four diploid cells two diploid cells four haploid cells two haploid cells
two haploid cells
