DNA/chromosome replication takes place during:

• G₁- phase

• G₂- phase

• S- phase

• Prophase

The S-phase of cell cycle is characterized by:

• duplication of chromosome

• shotening of chromosome

• duplication of DNA

• duplicatin of centriole

93.

Chiasmata are most appropriately observed in meiosis during :

• diakinesis

• diplotene

• metaphase II

• pachytene

Which is synthesized in G₁ phase ?

• DNA polymerase

• Histones

• Nucleolar DNA

• Tubulin protein

Which of the following maintain the constant number of chromosomes generation after generation?

• Meiosis

• Endomitosis

• Mitosis

• Amitosis

During the cell cycle, DNA content is doubled in the

• G₁ phase

• S phase

• G₂ phase

• end of M phase

Match the sub-stage of prophase I of meiosis in Column I and the events in Column II and choose the right option.

Column I	Column II
A. Leptotene	1. Terminalization of chiasma
B. Zygotene	2. Crossing over and recombination
C. Pachytene	3. Synapsis
D. Diakinesis	4.  Visibility of chromosomes

• A - 1; B - 2; C - 3; D - 4

• A - 1; B - 3; C - 2; D - 4

• A - 4; B - 3; C - 2; D - 1

• A - 4; B - 1; C - 2; D - 3

• A - 4; B - 1; C - 2; D - 3

Which one of the following is the significance of mitosis?

• Restricted to haploid cells

• Cell repair

• Increases the genetic variability

• Recombination of chromosomes

• Recombination of chromosomes

In a typical eukaryotic cell cycle, Gap 1, Synthesis and Gap 2 are the three phases included in the

• Prophase

• Metaphase

• Anaphase

• Interphase

• Interphase

Find out the correct statement

• During mitosis endoplasmic reticulum and nucleolus disappear completely at early prophase

• Chromosomes are arranged along the equator during prophase of mitosis

• Chromosome is made up of two sister chromatids at anaphase of mitosis

• A cell plate is laid down during interphase

• A cell plate is laid down during interphase