Haploid, Diploid and Polyploid Cells

Q.

Analyse the events during every stage of cell cycle and notice how the following two parameters change
(i) Number of chromosomes (N) per cell
(ii) Amount of DNA content (C) per cell

Q.

You have studied Mitosis in onion root tip cells.can you tell how many chromosomes will the cell have at G1 phase, after S phase, and after M phase? Also what will be the DNA content of the cells at G1, after S and at G2 , if the content after M phase is 2C?

Q.

If the diploid number of flowering plant is 36. what would be the chromosome number in its endosperm?

(a) 36 (b) 18 (c) 54 (d) 72

Q. The diploid chromosome number for the house fly is 12. The haploid number of chromosomes found in their gametes would be ______

1. 1
2. 3
3. 6
4. 12

Q. If a diploid cell is treated with colchicine, then it becomes:

1. Monoploid
2. Triploid
3. Tetraploid
4. Diploid

Q.

What would be the molar concentration of human DNA in a human cell? Consult your teacher.

Q.

Write one word for the following

1. Chromosome that appears V-shaped in anaphase stage.

Q.

What are conjugative and non-conjugative plasmids?

Q.

Discuss with your teacher about
(i) haploid insects and lower plants where cell-division occurs, and
(ii) some haploid cells in higher plants where cell-division does not occur.

Q.

Differentiate between the following pair on the basis of what is mentioned within brackets:

1. Human skin cell and Human ovum (number of chromosomes).

Q. A heavy DNA (${}^{15}N{-}^{15}N$) E.coli is allowed to replicate in (${}^{14}N$) medium for 60 minutes. What would be the proportion of light (${}^{14}N{-}^{14}N$) and hybrid density of DNA (${}^{14}N{-}^{15}N$) molecules?

Q.

Meiocyte of pea plant has 14 chromosomes, how many chromosomes will be there in the somatic cell of the pea plant?

1. 28

2. 14

3. 7

4. 56

Q. The greater the complexity of the organism, the greater the number of chromosomes within the cell.

1. True
2. False

Q. Differentiate between a zoospore and a zygote.

Q. An egg cell has $10$ pg of DNA in its nucleus. How much amount of DNA will be, in this animal at the end of $G_2$-phase of mitosis?

1. $10$ pg
2. $20$ pg
3. $30$ pg
4. $40$ pg

Q. A drug called colchicine is shown to interfere especially with spindle microtubules formation during mitosis. This would result in

1. Dehydration of chromosomes
2. Arrest of chromosome movements
3. Despiralization of chromosomes
4. Arrest of centrioles movements

Q.

what is the meaning of ploidy?

Q. Colchicine arrests mitosis at

1. Prophase
2. Metaphase
3. Anaphase
4. Interphase

Q. Karyokinesis is not followed by cytokinesis during the formation of the endosperm in some angiosperms like the coconut. This gives rise to

1. zygote of coconut
2. fertilised egg in yeast
3. multinucleate condition in endosperm
4. embryo in angiosperm

Q. In diploid zygote, chromosome number is 40. Chromosome number in a gamete will be

1. 10
2. 30
3. 20
4. 40

Q.

Discuss with your teacher about

(i) haploid insects and lower plants where cell-division occurs, and

(ii) some haploid cells in higher plants where cell-division does not occur.

Q. How are chromatin, chromatid and chromosomes related to each other?

Q. The diploid chromosome number for the house fly is 12. The haploid number of chromosomes found in their gametes would be ______

1. 1
2. 3
3. 6
4. 12

Q. The backbone of DNA is made up of?

1. Sugar only
2. Lipid and phosphate
3. Protein and phosphate
4. Sugar and phosphate

Q. Mention the reasons for the difference in ploidy of zygote and primary endosperm nucleus in an angiosperm?

Q. The number of DNA strands in chromosome at G2 stage is

1. one
2. two
3. four
4. eight

Q. The sex of an infant is not a case of inheritance of characteristics.

1. True
2. False

Q. If a diploid cell is treated with colchicine, then it becomes

1. Tetraploid
2. Diploid
3. Monoploid
4. Triploid

Q. Colchicine induces polyploidy by interfering with the spindle formation but the plant from which it is obtained remains unaffected

1. Due to presence of anticolchicine
2. Because colchicine remains inactive
3. Because spindle is made up of microfilaments in this plant
4. Because cells of this plant are already polyploid

Q. The centriole replicates during which stage of mitosis?

1. Interphase
2. Early prophase
3. Late prophase
4. Anaphase