Mastering Biology- Ch 12&13
A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes. A) 16 B) 32 C) 64 D) 30 E) 8
A
A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain? A) 92 B) 23 C) 23 or 46, depending on the portion of prophase examined D) 46 or 92, depending on the portion of prophase examined E) 46
A
Asexual reproduction _____. A) produces offspring genetically identical to the parent B) is limited to single-cell organisms C) leads to a loss of genetic material D) requires both meiosis and mitosis E) is limited to plants
A
Cytokinesis often, but not always, accompanies _____. A) telophase B) prometaphase C) anaphase D) interphase E) metaphase
A
During _____ sister chromatids separate. A) anaphase II B) prophase II C) metaphase I D) metaphase II E) telophase II and cytokinesis
A
Homologous chromosomes migrate to opposite poles during _____. A) anaphase I B) prophase II C) metaphase I D) metaphase II E) telophase II and cytokinesis
A
What goes on continuously in most parts of the body, rather than just the gonads? A) mitosis B) meiosis C) gametogenesis D) both mitosis and meiosis E) none of the above
A
Which of the following is a true statement about sexual vs. asexual reproduction? A) In sexual reproduction, individuals transmit 50% of their genes to each of their offspring. B) Asexual reproduction, but not sexual reproduction, is characteristic of plants and fungi. C) Asexual reproduction produces only haploid offspring. D) In asexual reproduction, offspring are produced by fertilization without meiosis. E) Sexual reproduction requires that parents be diploid.
A
Which of the following occurs during meiosis but not during mitosis? A) Synapsis occurs. B) Chromosomes align at the metaphase plate. C) A spindle apparatus forms. D) Chromosomes migrate to opposite poles. E) Chromosomes condense.
A
Why is it difficult to observe individual chromosomes with a light microscope during interphase? A) They have uncoiled to form long, thin strands. B) The DNA has not been replicated yet. C) Sister chromatids do not pair up until division starts. D) They leave the nucleus and are dispersed to other parts of the cell. E) The spindle must move them to the metaphase plate before they become visible.
A
What are haploid cells?
A cell containing only one set of chromosomes (n). These exist after both Meiosis I and Meiosis II
A human cell containing 22 autosomes and a Y chromosome is A) a somatic cell of a female. B) a sperm. C) a zygote. D) an egg. E) a somatic cell of a male.
B
At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids. A) telophase B) telophase I C) metaphase II D) telophase II E) interphase
B
Centromeres divide and sister chromatids become full-fledged chromosomes during _____. A) telophase B) anaphase C) prometaphase D) metaphase E) interphase
B
Chromosomes become visible during _____. A) anaphase B) prophase C) metaphase D) prometaphase E) interphase
B
During ____ chrome tetrads are aligned on the metaphase plate and kinetochore microtubules from one pole of the cell are attached to one homologous chromosome, while kinetochore microtubules from the other pole of the cell are attached to the other chromosome of the pair. A) telophase I and cytokinesis B) metaphase I C) metaphase II D) prophase II E) anaphase I
B
During ____ the chromosomes replicate. A) anaphase I B) interphase C) anaphase II D) prophase I E) prophase II
B
During _____ a spindle forms in a haploid cell. A) anaphase I B) prophase II C) metaphase I D) metaphase II E) telophase II and cytokinesis
B
During _____ both the contents of the nucleus and the cytoplasm are divided. A) mitosis B) the mitotic phase C) S D) G1 E) G2
B
During what stage do chromosomes line up by homologous pairs? A) mitosis only B) meiosis I only C) meiosis II only D) either mitosis or meiosis I E) either meiosis I or meiosis II
B
Homologous chromosomes pair during _________ A) metaphase I B) prophase I C) prophase II D) telophase II and cytokinesis E) metaphase II
B
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) 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. 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) Sister chromatids are only formed during mitosis. Homologous chromosomes are formed during meiosis.
B
If a hypothetical organism has 5 chromosomes in one of its gametes, then how many chromosomes must it have in a body cell? A) 5 B) 10 C) 15 D) 20 E) the answer cannot be determined
B
What is the process by which a single parent reproduces by itself? A) fertilization B) asexual reproduction C) meiosis D) gametogenesis E) sexual reproduction
B
Which of the following correctly matches a phase of the cell cycle with its description? A) G2: cell division B) G1: follows cell division C) S: immediately precedes cell division D) M: duplication of DNA E) All of the above are correctly matched.
B
At the end of _____ and cytokinesis there are four haploid cells. A) interphase B) prophase II C) telophase II D) prophase I E) anaphase I
C
During which substage do the nucleoli disappear and chromatin fibers coil up to become chromosomes? A) prometaphase B) interphase C) prophase D) anaphase E) telophase
C
During which substage of mitosis do sister chromatids break apart and start moving to opposite poles of the cell? A) prophase B) interphase C) anaphase D) metaphase E) telophase
C
Human gametes are produced by _____. A) mitosis B) fertilization C) meiosis D) asexual reproduction E) the cell cycle
C
In alternation of generations, what is the diploid stage of a plant that follows fertilization called? A) gametophyte B) chiasmata C) sporophyte D) karyotype E) spore
C
Meiosis II typically produces _____ cells, each of which is _____. A) four ... diploid B) two... diploid C) four ... haploid D) two ... haploid E) four ... identical to the other
C
What is the point of attachment between two duplicated chromosomes called? A) chromosome B) centrosome C) centromere D) telomere E) tetrad
C
What stage begins with the formation of a cleavage furrow, followed by a ring of microfilaments contracting at the site of the furrow, and finallythe cell is pinched in two and creates two daughter cells? A) cytokinesis as it occurs in plant cells B) prophase C) cytokinesis as it occurs in animal cells D) prometaphase E) metaphase
C
What phase is described below? This is the step in the cell cycle when the cytoplasm divides in two.
Cytokinesis
At the start of ______, the chromosomes are duplicated and lined up by homologous pair. A) the start of mitosis B) just before mitosis C) the start of meiosis II D) the start of meiosis I E) just after meiosis I
D
During ____ the chromosomes finish their journey and two haploid daughter cells are produced, each chromosome still consists of two sister chromatids. A) anaphase I B) metaphase I C) prophase I D) telophase I and cytokinesis E) metaphase II
D
During _____ a spindle forms in a haploid cell. A) telophase I and cytokinesis B) anaphase II C) prophase I D) prophase II E) metaphase II
D
During _____ chromosomes align single file along the equator of a haploid cell. A) anaphase II B) interphase C) anaphase I D) metaphase II E) prophase I
D
During _____ sister chromatids separate. A) metaphase I B) prophase I C) prophase II D) anaphase II E) interphase
D
During _____ the cell grows and replicates both its organelles and its chromosomes. A) S B) cytokinesis C) G1 D) interphase E) mitosis
D
During prophase a homologous pair of chromosomes consists of _____. A) one chromosome and two chromatids B) two chromosomes and two chromatids C) one chromosome and four chromatids D) two chromosomes and four chromatids E) four chromosomes and two chromatids
D
Genetic variation occurs when chromosomes are shuffled in fertilization and what other process?. A) mutation B) natural selection C) mitosis D) meiosis E) genetic drift
D
Homologous chromosomes migrate to opposite poles during _____. A) prophase I B) telophase I and cytokinesis C) metaphase II D) anaphase I E) prophase II
D
Meiosis I produces _____ cells, each of which is _____. A) two... diploid B) four ... diploid C) two... identical to the other D) two ... haploid E) four ... haploid
D
What process creates variation by producing chromosomes that combine the genes inherited from two parents? (this is when homologous chromosomes pair up very closely and corresponding parts of two non sister chromatids may trade places) A) random fertilization B) centromere separation C) karyokinesis D) crossing over E) cytokinesis
D
Which stage of mitosis is characterized by the disintegration of mitotic spindles and the formation of two new nuclear membranes? A) prophase B) prometaphase C) anaphase D) telophase E) metaphase
D
During _____ chromosomes align single file along the equator of a haploid cell. A) anaphase I B) metaphase I C) prophase I D) telophase I and cytokinesis E) metaphase II
E
During ____nuclei form at opposite poles of each dividing cell, and cells are split apart. This produces four haploid cells, each with one set of chromosomes A) anaphase I B) prophase II C) metaphase I D) metaphase II E) telophase II and cytokinesis
E
During which stage of mitosis are chromosomes lined up in the center of the cell? A) prometaphase B) prophase C) anaphase D) telophase E) metaphase
E
Normal human gametes carry _____ chromosomes. A) 46 pairs of B) 5 C) 23 pairs of D) 46 E) 23
E
Nucleoli are present during _____. A) metaphase B) prometaphase C) prophase D) anaphase E) interphase
E
Spindle fibers attach to kinetochores during _____. A) anaphase B) metaphase C) cytokinesis as it occurs in plant cells D) interphase E) prometaphase
E
Spindle fibers attach to kinetochores during _____. A) interphase B) anaphase C) telophase D) metaphase E) prometaphase
E
Synapsis occurs during _____. A) anaphase II B) metaphase II C) telophase I and cytogenesis D) prophase II E) prophase I
E
What is crossing over? A) the movement of genetic material from one chromosome to a nonhomologous chromosome B) also referred to as the "independent assortment of chromosomes" C) making an RNA copy of a DNA strand D) a direct consequence of the separation of sister chromatids E) the exchange of homologous portions of nonsister chromatids
E
What stage begins when vesicles containing cell-wall material collect in the middle of the cell, the vesicles fuse, form a large sac called the cell plate, which grows outward until its membrane fuses with the plasma membrane and separates the two daughter cells? A) prophase B) metaphase C) prometaphase D) anaphase E) cytokinesis as it occurs in plant cells
E
Why do some species employ both mitosis and meiosis, whereas other species use only mitosis? A) They need only mitosis to make large numbers of cells such as sperm. B) They need only meiosis if they produce egg cells. C) They need meiosis if the cells are producing organs such as ovaries. D) A single-celled organism only needs mitosis. E) They need both if they are producing animal gametes.
E
What phase is described below? This is the portion of the cell cycle just after division, but before DNA synthesis. During this time the cell grows by producing proteins and organelles.
G1
What phase is described below? This third subphase of interphase is a period of metabolic activity and growth. During this phase the cell makes final preparations for division.
G2
What phase is described below? Typically, this phase accounts for 90% of the cell cycle. It is a time of high metabolic activity. The cell grows by producing proteins and organelles, and chromosomes are replicated.
Interphase
What phase is described below? This is when division of the nucleus occurs. The chromosomes that have been replicated are distributed to two daughter nuclei.
Mitosis
What phase is described below? Cell division occurs during this short phase, which generally involves two discrete processes: the contents of the nucleus (mainly the duplicated chromosomes) are evenly distributed to two daughter nuclei, and the cytoplasm divides in two.
Mitotic Phase (M)
What phase is described below? DNA synthesis (or replication) occurs during this phase. At the beginning of the phase, each chromosome is single. At the end, after DNA replication, each chromosome consists of two sister chromatids.
S