Download Grade 11 : Biology

Grade 11 : Biology
Worksheet on Cell division
True/False
Indicate whether the sentence or statement is true or false.
____
1. Tissue growth requires cell growth.
____
2. Cells divide rather than continue to increase in size to facilitate the exchange of materials through the cell
membrane.
____
3. The stage between nuclear divisions in mitosis is called cytokinesis.
____
4. In animal cells, the separation of new cells produced by mitosis is accomplished by a cell plate that forms
between the two chromatin masses.
____
5. A clone is a combination of the genetic material of two parent cells.
____
6. A cell without a nucleus is referred to as totipotent.
____
7. In general, cancer cells divide at slower rates than normal cells.
____
8. Cancer cells lack the ability to differentiate.
____
9. Meiosis is a process by which gametes are formed.
____ 10. In humans, the haploid number of chromosomes is 46 and the diploid chromosome number is 23.
____ 11. All daughter cells produced by meiosis are genetically identical to each other and to the parent.
____ 12. Mitosis, combined with fertilization, explains the variation in traits that is observed in species that reproduce
sexually.
____ 13. The formation of sex cells during meiosis is referred to as gametogenesis.
____ 14. Chromosomes that are not sex chromosomes are referred to as autosomes.
____ 15. Down syndrome is an example of a nondisjunction disorder.
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____ 16. Which of the following events is not characteristic of interphase?
a. The cell is inactive.
b. Proteins are synthesized for the next mitotic division.
c. Proteins are synthesized for cell growth and metabolism
d. The genetic material duplicates in preparation for mitosis.
e. The genetic material is referred to as chromatin.
____ 17. The series of events that takes place from the formation of a cell until it divides again is called
a. mitosis.
d. the cell cycle.
b. meiosis.
e. fertilization.
c. cell growth.
____ 18. If one of two newly formed daughter cells has one extra chromosome, and the other daughter cell has one
less, the problem in the preceding mitotic division probably occurred in
____ 19.
____ 20.
____ 21.
____ 22.
____ 23.
____ 24.
____ 25.
____ 26.
a. prophase.
d. telophase.
b. metaphase.
e. cytokinesis.
c. anaphase.
The proper sequence of mitosis is
a. prophase, anaphase, metaphase, telophase
b. prophase, telophase, anaphase, metaphase.
c. metaphase, prophase, anaphase, telophase
d. telophase, prophase, metaphase, anaphase
e. prophase, metaphase, anaphase, telophase.
What is the correct sequence of the following events that occur in mitosis?
1. The cytoplasm and organelles are divided between the daughter cells.
2. The nucleolus and nuclear envelope reappear.
3. The centromere splits.
4. The chromosomes condense and the nucleolus disappears.
5. The chromosomes are pulled to the poles of the cell.
6. The chromosomes line up on the equatorial plane.
a. 2, 1, 3, 6, 5, 4
d. 4, 6, 3, 5, 2, 1
b. 1, 4, 3, 5, 6, 2
e. 4, 6, 3, 2, 5, 1
c. 4, 3, 6, 5, 1, 2
Which of the following structures disappears in prophase and reappears in telophase?
a. centromeres
d. spindle fibres
b. cell membrane
e. nuclear membrane
c. chromosomes
During anaphase of mitosis
a. centrioles divide.
b. chromosomes migrate toward poles.
c. asters and spindle form.
d. nuclear membranes reform.
e. chromosomes attach to spindle fibres
If a cell with 36 chromosomes undergoes mitosis, each daughter cell will have
a. 36 chromosomes.
d. 9 chromosomes.
b. 72 chromosomes.
e. 6 chromosomes.
c. 18 chromosomes.
If the centromere in one of your 46 chromosomes does not split until telophase, it would result in
a. two cells, each with 46 chromosomes.
b. two cells, each with 23 chromosomes.
c. two cells, one with 45 chromosomes and one with 47 chromosomes.
d. two cells, one with 23 chromosomes and one with 46 chromosomes.
e. two cells, one with 40 and chromosomes and one with 52 chromosomes.
A certain cell undergoes mitosis every 20 min. The number of cells produced from one original cell after 1 h
20 min. would be
a. 2.
d. 80.
b. 16.
e. 8.
c. 32.
Which cells in the human body have a diploid number of 46 chromosomes in their nuclei?
a. all cells
b. only the reproductive cells
c. only cells that are produced by meiosis
d. only zygotes
____ 27.
____ 28.
____ 29.
____ 30.
____ 31.
____ 32.
____ 33.
____ 34.
____ 35.
e. only cells that are produced by mitosis
An important feature of meiosis is that it
a. results in the production of a fertilized egg cell.
b. minimizes the number of genetically different gametes.
c. doubles the chromosome number between successive generations.
d. maintains the same number of chromosomes in the organism between generations.
e. reduces the number of chromosomes in the organism between generations.
A cell in a human testis is undergoing meiosis. What is the sequence of the following events?
1. A cell division occurs without the duplication of chromosomes.
2. The chromosomes replicate in interphase.
3. Haploid cells are formed.
4. Without separation of the centromere, the chromosomes move to the poles of the cell.
5. The centromere splits and the chromosomes move to the poles of the cell.
a. 2, 4, 5, 1, 3
d. 2, 5, 1, 4, 3
b. 1, 5, 4, 3, 2
e. 2, 1, 5, 4, 3
c. 4, 1, 5, 2, 3
Which statement does not describe the interphase between telophase I and prophase II of meiosis?
a. Replication of DNA occurs.
b. In most cells, the chromosomes have uncoiled.
c. If present, centrioles migrate to opposite poles.
d. In most cells, a nuclear membrane surrounds the chromosomes.
e. The cells contain chromosomes with a mixture of paternal and maternal genes.
During meiosis, genetic variation in the gametes is achieved by
a. replication and fertilization.
d. crossing over and random assortment.
b. crossing over and replication.
e. replication and random assortment.
c. crossing over and fertilization.
Each human cell may contain as many as 100 000 genes. Most of these are represented by two copies in each
of your body cells. How many copies of each gene would be in a single cell in telophase I of meiosis?
a. 1
d. 4
b. 2
e. 8
c. 3
Which is a result of meiosis?
a. Chromosome number is reduced to one-half the original number.
b. New combinations of genes are produced when crossing over occurs.
c. Maternal and paternal chromosomes are mixed when homologous chromosomes separate
independently.
d. Genetic variation is maintained within species.
e. All of these choices are results of meiosis.
Classify the following statement: The centromere splits prior to the separation of the chromosomes.
a. mitosis
d. neither mitosis nor meiosis
b. meiosis
e. both mitosis and meiosis
c. fertilization
Classify the following statement: The chromosomes are replicated in interphase.
a. mitosis
d. neither mitosis nor meiosis
b. meiosis
e. both mitosis and meiosis
c. fertilization
Classify the following statement: The daughter cells have the same number of chromosomes as the parent
cell.
a. mitosis
d. neither mitosis nor meiosis
____ 36.
____ 37.
____ 38.
____ 39.
____ 40.
____ 41.
____ 42.
____ 43.
____ 44.
____ 45.
b. meiosis
e. both mitosis and meiosis
c. fertilization
Classify the following statement: This type of nuclear division helps maintain the number of chromosomes
from generation to generation.
a. mitosis
d. neither mitosis nor meiosis
b. meiosis
e. both mitosis and meiosis
c. fertilization
If one pair of your 23 pairs of chromosomes does not separate during anaphase I of meiosis, the consequence
would be the production of
a. four cells, each with 23 chromosomes.
b. four cells, two with 23 chromosomes and two with 46 chromosomes.
c. four cells, two with 45 chromosomes and two with 47 chromosomes.
d. four cells, two with 22 chromosomes and two with 24 chromosomes.
e. four cells, two with 23 chromosomes and two with 47 chromosomes.
The haploid chromosome number in humans is
a. 23.
d. 92.
b. 46.
e. 69.
c. 48.
If a sperm cell contains 18 chromosomes, a muscle cell from the same organism will contain
a. 9 chromosomes.
d. 18 pairs of chromosomes.
b. 9 pairs of chromosomes.
e. 27 chromosomes.
c. 18 chromosomes.
The genetic defect known as Down Syndrome is due to
a. an extra chromosome.
d. a missing sex chromosome.
b. a nonfunctional enzyme.
e. two female sex chromosome
c. linkage and crossing over.
How many chromosomes would occur in each body cell of a person who has combined Down/Klinefelter
syndrome?
a. 23
d. 47
b. 45
e. 48
c. 46
Down Syndrome
a. occurs only in females.
d. is caused by a missing chromosome.
b. occurs in males and females equally.
e. occurs only in males.
c. is a result of an extra chromosome.
Which of the following is characteristic of meiosis but not of mitosis?
a. involves cell division
b. occurs in both plants and animals
c. results in chromosome reduction to a single set
d. involves a distribution of chromosomes to daughter nuclei
e. involves the movement of chromosomes
The events which occur in both mitosis and meiosis are similar except during
a. anaphase.
b. chromosomal duplications.
c. mitotic metaphase and first meiotic metaphase.
d. mitotic metaphase and second meiotic metaphase.
e. the first interphase.
During which stage would it be most easy to distinguish a cell undergoing mitosis from a similar cell
undergoing the first meiotic division?
a. telophase
d. metaphase
b. prophase
e. interphase
c. anaphase
____ 46. Which of the following would you find at the end of the telophase I stage of meiosis?
a. one haploid cell
d. one diploid cell
b. two haploid cells
e. two diploid cells
c. four haploid cells
Completion
Complete each sentence or statement.
47. Cell division allows cells to ____________________, to reproduce, and to ____________________,
damaged and worn tissues.
48. Early researchers divided the cell cycle into two distinct phases:
i) _____________________, ii) _____________________.
49. During _____________________, the cell's cytoplasm is divided into two daughter cells.
50. At the beginning of mitosis, sister chromatids are attached at a point called the _____________________.
51. If the nucleus is removed from one egg cell and replaced with the nucleus from an embryo, the offspring is
a(n) _____________________ of the cell that donates the nucleus.
52. When cancer cells can dislodge from a tumour and move to another area, _____________________ is
occurring.
53. Meiosis produces _____________________ cells, while fertilization produces a _____________________
cell.
54. In the life cycle of an animal, meiosis produces _____________________.
55. ____________________ is the pairing of homologous chromosomes during meiosis.
56. The failure of chromosomes to separate during anaphase of meiosis is known as _____________________.
Short Answer
57. What is the basic function of meiosis, and why is it necessary?
58. List five differences between mitosis and meiosis.
59. Explain why two nuclear divisions are necessary to produce four haploid nuclei from a single diploid nucleus.
60. Distinguish between mitosis and cytokinesis.
61. Why is it that cells divide rather than increase in size?
62. Identify the events that occur during the two phases of the cell cycle.
63. Explain the differences that occur during cytokinesis in a plant and an animal cell.
64. Name three differences between cancer cells and normal cells.
65. Give (a) the type of cells in which you would find a diploid number of chromosomes and a haploid number of
chromosomes, and (b) the haploid and diploid numbers of chromosomes in humans.
66. Explain why homologous chromosomes are paired.
67. Identify where meiosis takes place in animal cells, and what is produced.
68. Illustrate spermatogenesis using the chromosome number and number of cells at each division.
Problem
69. Complete the following table showing the number of chromosomal DNA molecules and chromosomes for
different cells. Use the human chromosome number: diploid, 2n = 46 and haploid, n = 23. Assume one DNA
molecule per chromatid
Stage
# of chromosomal DNA
# of chromosomes per cell
molecules per cell
unfertilized egg cell
zygote (fertilized egg cell)
body cell prior to DNA
replication
body cell after DNA
replication
meiotic prophase I cell
meiotic I telophase cell
meiotic II telophase cell
23
23
70. Calculate the surface area to volume ratio for:
a) Cube 1 - dimensions 2 cm × 2 cm × 2 cm. SHOW YOUR WORK!
b) Cube 2 - dimensions 5 cm (s) 5 cm (s) 5 cm. SHOW YOUR WORK!
c) If these cubes represented cells, which Cube represents a problem in terms of surface area to volume
ratio? Explain the reason for your answer.
Essay
71. The purpose of mitosis is to divide a double set of DNA equally between two daughter cells. Explain the
significance of each of the following events with regard to mitosis.
a) The chromatin condenses into chromosomes.
b) The nucleolus and the nuclear envelope disappear.
c) The chromosomes line up at the equator of the cell.