Cell Cycle Control

Q. Which of the following is not a phase of interphase?

1. M phase
2. $G_1$ phase
3. $G_2$ phase
4. S phase

Q.

Which one of these is NOT an in-built property of the cell to prevent unwanted division?

1. Contact inhibition
2. Anchorage dependence
3. Cell cycle checkpoints
4. DNA repair mechanism

Q.

In growing cells there are two classes of proteins that can trigger or check the progression of the cell cycle from the G1 phase to the M phase. These protein classes are called (i)______ and (ii)______ . (iii)______ is the English biochemist who discovered (i)______; they are so named because their significance is in the initiation and regulation of the cell division process in a (iv)______.

1. (i) CDK (ii) Tim Hunt (iii) Cyclic manner (iv) Cyclins

2. (i) Cyclins (ii) CDK (iii) Tim Hunt (iv) Cyclic manner

3. (i) Tim Hunt (ii) Cyclic manner (iii) Cyclins (iv) CDK

4. (i) Cyclic manner (ii) Cyclins (iii) CDK Tim Hunt

Q. More than One Answer Type
एक से अधिक उत्तर प्रकार के प्रश्न

During the S-phase of cell cycle

कोशिका चक्र की S-प्रावस्था के दौरान

1. Deoxyribonucleic acid is replicated
   
   डिऑक्सीराइबोन्यूक्लिक अम्ल प्रतिकृत होता है
2. Centriole duplicates in the cytoplasm
   
   तारककेंद्र, कोशिकाद्रव्य में द्विगुणित होता है
3. Chromatin begins to condense
   
   क्रोमैटिन का संघनन आरंभ होता है
4. Number of chromosomes gets doubled as DNA gets doubled
   
   डीएनए (DNA) के दोगुना होने पर गुणसूत्र की संख्या दोगुनी हो जाती है

Q.

Which of these best describes the role and mechanism of action of Cyclin-dependent kinases (CDKs) in the cell cycle?

1. CDKs bind to cyclin, the formed complex is in an activated state.

2. Cyclins are a family of proteins that control the progression of cells through the cell cycle

3. Through phosphorylation, CDKs signal the cell that it is ready to pass into the next stage of the cell cycle.

4. All of the above

Q. When a replication fork stops midway in a cell, which checkpoint must get activated predominantly?

1. M
2. Both G2/M and M
3. G1/S
4. G2/M

Q.

The division phase of a cell, either in mitosis or meiosis is regulated by proteins called _____ and their dependent enzyme complexes called ______.

1. Cyclins $\&$ CDK
2. Histones $\&$ CDK
3. Cyclins $\&$ Histones
4. Histones $\&$ Lyases

Q.

Which of these statements is absolutely true for cell cycle?

1. A cell in $G_1$ phase of division can go back to the previous M phase if DNA was not divided properly

2. In S phase checkpoint, if replication does not occur correctly, the cell re-enters S phase

3. ​If the cell is found abnormal or damaged beyond repair, the checkpoints regulate the apoptosis of the cell

4. Although cell cycle is unidirectional, in the presence of certain hormones, it may be reversed.

Q.

Which of these would be required for the regulation of cell cycle ?

1. CDK

2. Cyclin

3. Cyclin-CDK Complex

4. Phosphorylated CDK