Assertion (A): | Meiosis leads to recombinations of genes. |
Reason (R): | Crossing over occurs in pachytene sub-stage of prophase I of meiosis. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Match each item in Column I with one item in Column II and chose your answer from the codes given below.
Column I (stage of prophase I) |
Column II (event) |
I. Zygotene II. Pachytene III. Diplotene IV. Diakinesis |
1. Crossing over 2. Chiasmata formation 3. Bivalent formation 4. Terminalization of chiasmata |
Codes:
I II III IV
1. 1 2 3 4
2. 2 1 4 3
3. 3 1 2 4
4. 3 2 1 3
Match the following column I with column II.
Column I | Column II |
A. Synapsis aligns homologous chromosomes | (i) Anaphase II |
B. Synthesis of RNA and protein | (ii) Zygotene |
C. Action of enzyme recombinase | (iii) G2 - phase |
D. Centromeres do not separate, but chromatids move towards opposite poles | (iv) Anaphase I |
(v) Pachytene |
1. A-(ii) B-(i) C-(iii) D-(iv)
2. A-(ii) B-(iii) C-(v) D-(iv)
3. A-(i) B-(ii) C-(v) D-(iv)
4. A-(ii) B-(iii) C-(iv) D-(v)
Match the following
Column l Column ll
a phase (i) Longest phase of cell cycle
b M phase (ii) Synthesis of histone proteins
c S-phase (iii) Cell quiescence
d phase (iv) Nuclear division
1. a(i), b(i), c(iv), d(iii)
2. a(i), b(iv), c(ii), d(iii)
3. a(i), b(iv), c(iii), d(ii)
4. a(iv), b(iii), c(i), d(ii)
List I | List II |
A. Pairing of homologous chromosomes | I. Chiasmata |
B. Actual interchange of segments between two homologous chromosomes | II. Synaptonemal complex |
C. Protein body formed between paired homologs | III. Synapsis |
D. The cross shaped configuration visible between homologs | IV. Crossing over |
Read the four statements (a-d) and choose the correct option.
a. Spindle fibers attach to kinetochores of chromosomes during metaphase.
b. Cell growth results in disturbing the ratio between the nucleus and the cytoplasm.
c. Pachytene stage is relatively short-lived compared to the leptotene.
d. Interkinesis is a short-lived stage characterized by duplication of DNA.
1 a, b & c are correct
2 Only c is incorrect
3 b & d are correct
4 a & b are correct
Consider the following four statements (I- IV) related to cell cycle, and select the correct option stating them as true (T) and false (F)
I. Cell growth in terms of cytoplasmic increase is a continuous process.
II. Interphase is the phase of actual cell division.
III. The number of chromosomes doubles in S-phase.
IV. The cell that do not divide further exist G1-phase to enter an inactive stage.
Options :
I II III IV
1. T F F F
2. F T T T
3. F F T T
4. T F F T
Consider the following four statements (I- IV) related to cell cycle, and select the correct option stating them as true (T) and false (F).
I. Cell growth in terms of cytoplasmic increase is a continuous process.
II. Interphase is the phase of actual cell division.
III. The number of chromosomes doubles in S-phase.
IV. The cell that does not divide further exits G1-phase to enter a metabolically inactive stage.
Options:
I II III IV
1. T F F F
2. F T T T
3. F F T T
4. T F F T