Which stage of meiosis is shown in the diagram given below?
1. | Metaphase I | 2. | Metaphase II |
3. | Anaphase I | 4. | Anaphase II |
In meiosis:
1. | A single round of DNA replication is followed by two sequential divisions with chromosome number and DNA content getting reduced twice |
2. | A single round of DNA replication is followed by two sequential divisions with chromosome number getting reduced twice and DNA content getting reduced once |
3. | A single round of DNA replication is followed by two sequential divisions with chromosome number getting reduced once and DNA content getting reduced twice |
4. | A single round of DNA replication is followed by two sequential divisions with chromosome number and DNA content getting reduced once |
The mechanisms that contribute to the genetic variation arising from sexual reproduction include:
I: | Independent assortment of chromosomes |
II: | Crossing over |
III: | Random fertilization |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II and III |
At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype?
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
A prolonged resting phase in oogenesis as seen in many vertebrate oocytes is called as:
1. Interkinesis
2. Diakinesis
3. Diplotene
4. Prometaphase II
Place stages of Prophase I in correct order.
1. diakinesis, diplotene, leptotene, pachytene, zygotene.
2. diplotene, leptotene, pachytene, zygotene, diakinesis.
3. leptotene, pachytene, diakinesis, diplotene, zygotene.
4. leptotene, zygotene, pachytene, diplotene, diakinesis
DNA replication takes place during :
1. | G1 - phase | 2. | G2 - phase |
3. | S - phase | 4. | Prophase |
Identify the human cell for which the interphase period lasts the entire life of a person.
1. | Hepatocyte | 2. | Bone marrow stem cells |
3. | Epidermal cell | 4. | Neuron |
Consider the following functions:
I: | Replication of DNA along with the synthesis of nuclear proteins such as histones |
II: | Duplication of centriole |
III: | Synthesis of energy rich compounds and proteins |
Which of the above functions are carried out by a plant cell before it divides?
1. | I only | 2. | I, and II |
3. | I and III | 4. | I, II and III |
The duration of which of the following is constant in most cell types?
1. G1 phase, S phase and G2 phase
2. S phase, M phase and G1 phase
3. S phase, G2 phase and M phase
4. G1 phase, M phase and G2 phase