Week Four: Mitosis and Meiosis
C
A cell has 40 duplicated chromosomes. How many centromeres are in this cell? A. 10 B. 20 C. 40 D. 60
A
A cell is through meiosis I and is entering meiosis II. Which of the following statements is true of its contents? A. It has half the amount of DNA as the cell that began meiosis. B. It has half the chromosome number but twice the DNA of the originating cell. C. It has one-fourth the DNA and one-half the chromosomes as the originating cell. D. It is identical in content to another cell formed from the same meiosis I event.
A
A cell that has 20 chromosomes undergoes mitosis. Which of the following is true? A. two daughter cells will be created, each will have 20 chromosomes B. two daughter cells will be created, each will have 10 chromosomes C. four daughter cells will be created, each will have 20 chromosomes D. two daughter cells will be created, each will have 40 chromosomes
A
A cell that has just exited the G1 phase of the cell cycle (and will eventually go on to divide) will next enter ___________________. A. the S phase B. the M phase C. anaphase D. the G2 phase
A C
A chromosome that consists of two sister chromatids is (select all that apply): A. in a cell going through cell division. B. haploid. C. replicated. D. unreplicated. E. diploid.
B
Cat somatic (body) cells contain 38 chromosomes. How many sister chromatids will a somatic cell contain after the S-phase of mitosis? A. 38 or 76, depending upon when in prophase you examine the cell B. 76 C. 19 or 38, depending upon when in prophase you examine the cell D. 38
C
Chromosomes condense and begin to be visible during _____________. A. metaphase B. anaphase C. prophase D. telophase
E
Crossing over occurs during which stage of meiosis? A. metaphase II B. metaphase I C. interphase D. prophase II E. prophase I
C
Cytokinesis begins during which phase? A. metaphase B. anaphase C. telophase D. S-phase
B
Diatoms are protists that have glass walls. They carry out cytokinesis similarly to ______________. A. animals B. plants C. mitochondria D. bacteria
A C D
During Meiosis I (select all that apply): A. crossing-over occurs between homologous chromosomes. B. the DNA replicates. C. homologous chromosomes separate. D. independent assortment of chromosomes occurs.
C
During cell division, each chromosome consists of 2 ___________________. A. cleavage furrows B. daughter cells C. chromatids D. chromosomes
B
During which phase of the cell cycle does the DNA make a copy of itself? A. G2 B. S C. G1 D. mitosis
C
During which stage of mitosis do chromosomes first become visible? A. telophase B. metaphase C. prophase D. interphase
D
How does meiosis maintain the genetic variation in a species? A. Meiosis allows recombination of alleles when non-homologous chromosomes undergo crossing over. B. Meiosis increases the ploidy number of a cell. C. Meiosis produces only gametes with a parental genotype. D. Meiosis results in gametes with different combinations of parental chromosomes.
D
How many different genetic combinations would independent assortment produce in a mosquito (2n = 6)? A. 3 B. 6 C. 4 D. 8
B
How many pairs of homologous chromosomes are found in human males? A. 23 B. 22 C. 46 D. 44
D
If a fertilized egg (zygote) goes through six cell divisions - how many cells would be found in the early embryo? A. 12 B. 16 C. 32 D. 64
D
If a species has 50 chromosomes in each diploid non-reproductive cell, then how many different chromosomal combinations are possible during gamete production? A. 2 x 50 B. 2^(50) C. 2 x 25 D. 2^(25)
A
If there are 32 centromeres in a cell at metaphase, how many chromosomes are there in each daughter cell following cytokinesis? A. 16 B. 32 C. 64 D. 32 at the start of cytokinesis and 64 at the end of cytokinesis
B
In a diploid species, meiosis produces haploid gametes. How is the diploid number restored for these species ? A. DNA replication during S phase. B. Fertilization. C. Independent assortment of chromosomes. D. segregation of homologous chromosomes.
D
In a sample of cells, the DNA content immediately following mitosis is measured and is equal to 10 picograms of DNA per nucleus. How much DNA would be found in each nucleus at the end of S and the end of G2? A. 10 picograms; 10 picograms B. 10 picograms; 20 picograms C. 10 picograms; 5 picograms D. 20 picograms; 20 picograms
B
In a tissue that is going through active growth, cell A has twice as much DNA as cell B. Which of the following is most likely true? A. Both Cell A and Cell B have passed through G2. B. Cell A is in G2 and Cell B is in interphase. C. Both Cell A and Cell B are in interphase. D. Cell A is in G1 and Cell B is in interphase.
C
In an organism with a chromosome complement of 2N = 38, how many possible chromosomal arrangements does independent assortment produce? A. 19 B. 38 C. 2^19 D. 2^38 E. 3^82 F. 19^2
C
Independent assortment occurs: A. when homologous chromosomes undergo synapsis during Prophase I. B. when homologous chromosomes separate after Metaphase I. C. due to the random alignment of homologous chromosome pairs during Metaphase I. D. at fertilization.
C
Many species of dinoflagellates (single-celled organisms) are able to reproduce both sexually and asexually. In which of the following scenarios would they most likely reproduce sexually? A. When the environment is relatively stable and unchanging. B. Whether these organisms reproduce sexually or asexually is most likely random. C. When the environment is changing. D. When there are a large number of other dinoflagellates around to mate with.
D
Meiosis II is similar to mitosis in that: A. homologous chromosomes pair and undergo synapsis. B. DNA replication takes place before both mitosis and meiosis II. C. the daughter cells have a different ploidy level than the parent cell. D. sister chromatids separate during anaphase.
D
Most species of earthworms have 3 homologous pairs of chromosomes. How many different chromosomal arrangements are possible in the gametes of earthworms as a result of independent assortment? A. 6 B. 12 C. 9 D. 8
D
Non-homologous chromosomes A. separate during Meiosis II. B. cross over during mitosis. C. are similar, but there are some genetic differences between them. D. assort independently of each other during Meiosis I.
A
Sperm cells and ova can be classified as _____ cells. A. haploid B. clonal C. diploid D. nonreproductive E. zygote
B
Starting with a cell in interphase, what is the correct sequence of events that leads to the formation of two daughter nuclei? A. prophase, prometaphase, anaphase, telophase B. prophase, prometaphase, metaphase, anaphase, telophase C. prophase, prometaphase, metaphase, telophase D. prophase, metaphase, anaphase, telophase
B
Starting with one cell, how many daughter cells will be formed when meiosis is complete? A. 8 B. 4 C. 2 D. 1
A
The cellular process by which gametes are formed from specialized nonreproductive cells is _____ . A. meiosis B. mitosis C. cloning D. asexual reproduction E. fertilization
B
Which of the following describes how mitosis differs from meiosis? A. Gamete production only occurs in meiosis. B. Homologous chromosomes pair in meiosis only. C. Only cells about to enter mitosis replicate their chromosomes. D. Only mitosis produces haploid cells from diploid cells.
B
What is a result of mitosis? A. A decrease in the number of chromosomes in the cell B. Maintaining the number of chromosomes in the cell C. An increase in the number of chromosomes in the cell
A
What is the result of meiosis? A. A decrease in the number of chromosomes in the cell B. Maintaining the number of chromosomes in the cell C. An increase in the number of chromosomes in the cell
C
What would happen if a cell were unable to properly condense its chromosomes during prophase? A. Centrosomes would not form. B. The parental cell would not grow. C. The chromosomal DNA would be subjected to shearing forces, fragmenting the chromosome. D. DNA synthesis would not occur.
D
What would happen if cytokinesis occurred before telophase was completed? A. The chromatids would not move. B. The chromosomes would not replicate. C. Nothing. This is the normal sequence of events. D. One cell would probably not get a nucleus.
A
What would happen if one chromosome failed to have microtubules from both poles attach? A. One daughter cell would get an extra copy of that chromosome. B. The poles would not form properly. C. Nothing. Mitosis would be normal. D. All chromosomes would migrate to one pole.
D
What would happen to a cell if it went directly from prometaphase to anaphase (i.e., it failed to undergo metaphase)? A. The chromosomes would not condense. B. Nothing. C. The nuclear envelope would not break down. D. The daughter cells would probably not get equal numbers of chromosomes.
A
When do homologous chromosomes pair? A. during meiosis I B. during meiosis II C. during mitosis D. prior to meiosis
A
When do homologous chromosomes pair? A. during meiosis I B. during meiosis II C. during mitosis D. prior to meiosis
D E
When it proceeds without errors, the process of mitosis results in (select all that apply) A. DNA being replicated without errors. B. each new cell being genetically different from its parent. C. each cell dividing at the appropriate time. D. division of the nucleus. E. each new cell receiving the proper number of chromosomes.
C
Which of the following environments would predictably have the most organisms that reproduce asexually? A. A temperate lake experiencing the effects of global warming. B. The advancing edge of a retreating glacier. C. A tropical forest where the temperature, humidity, and sunlight are relatively stable and nutrients are in ample supply. D. A northern forest where the temperature, humidity and sunlight vary throughout the year, and nutrients are seasonal.
B
Which of the following is a characteristic of the dinoflagellates? A. phycobilins B. alveoli C. chlorophyll b D. stramen
B C F
Which of the following is true of a homologous pair of chromosomes? Select all that apply. A. They are genetically identical. B. They are genetically similar, but there are some differences between them. C. They are separated during Meiosis I. D. They are separated during Meiosis II. E. they are found in haploid cells. F. They are found in diploid cells.
C
Which of the following is true of a sexually reproducing organism that is 2n= 28? A. The species is diploid with 56 chromosomes per cell. B. The species has 28 sets of chromosomes per cell. C. Each diploid cell has 14 homologous pairs. D. A gamete from this species has 7 chromosomes.
A C E
Which of the following is true of crossing over during cell division. Select all that apply. A. It creates new combinations of genetic material. B. It occurs during mitosis. C. It occurs during meiosis. D. It occurs between sister chromatids. E. It occurs between non-sister chromatids
C
Which of the following is true of mitosis in a diploid cell? A. It results in two haploid daughter cells. B. It does not require replication of the cell's DNA before cell division. C. It results in daughter cells that are genetically identical, but physically smaller, than the original parent cell. D. Most animals use it for reproduction.
A
Which of the following is true of mitosis in a human cell? A. It results in genetically identical 2n somatic cells. B. It results in genetically different 2n somatic cells. C. It results in genetically identical 1n somatic cells D. It results in genetically identical 2n gamete cells
A
Which of the following statements about homologous chromosomes is most accurate? A. They are genetically similar. B. They are the same as sister chromatids. C. They pair during mitosis. D. They are genetically identical.
C
Which of the following statements about meiosis is NOT true? A. Meiosis is required for sexual reproduction. B. At the end of Meiosis I, the ploidy level of the daughter cells is half that of the parent cell. C. Independent assortment occurs during Meiosis II. D. Crossing over occurs during Prophase I.
C E
Which of the following statements is true of two sister chromatids that are joined at the centromere prior to mitosis? (Select all that apply). A. These chromatids make up a diploid chromosome. B. The cell that contains these sister chromatids must be diploid. C. The two sister chromatids are the result of DNA replication. D. One of the sister chromatids is paternal in origin and the other is maternal in origin. E. The two sister chromatids are genetically identical.
A
Which of the following statements is true? A. During mitosis, the homologous chromosomes do not typically pair; however, in meiosis they always do so. B. During both mitosis and meiosis the ploidy level of the daughter cells is half the ploidy level of the parent cell. C. Crossing over can occur in both mitosis and meiosis. D. Prior to mitosis, DNA replicates once; prior to meiosis it replicates twice.
A
Which of the following types of reproduction produces offspring that are genetically distinct from their parents? A. sexual B. binary fission C. vegetative propagation D. asexual E. cloning
B
Which one of the following statements about sex is true? A. All organisms have sexual reproduction. B. Sex is the exchange of genetic material. C. Sexual reproduction produces offspring that are genetically identical to their parents. D. Sex requires the formation of eggs and sperm. E. All of these are true of sex.
D
You are working in a cytology lab and have isolated cells in different phases of the cell cycle. In G1 phase cells you found 8 picograms of DNA. In another group you found cells with 12 picograms of DNA. The cells of this group are most likely in _________________________. A. between the G1 and the start of S phase in the cell cycle B. in the G2 phase of the cell cycle C. in the M phase of the cell cycle D. in the S phase of the cell cycle