Identify the correct statement with regard to
G1 phase (Gap 1) of interphase.
AI-generated explanation. Check against your textbook.
Explanation:
During G1 (the first gap phase) of interphase, the cell is metabolically active and grows in size. It does not replicate its DNA; DNA replication occurs in the S phase. G1 prepares the cell for DNA synthesis by producing RNA and proteins required for DNA replication and by increasing cytoplasmic components. Therefore, the correct statement is 3: “Cell is metabolically active, grows but does not replicate its DNA.”
🧠 Did You Know?
G1 is followed by S phase, then G2; together these phases constitute interphase, before mitosis (M phase).
💡 NCERT Memory Line:
“In G1, the cell grows and carries out normal metabolic activities; DNA replication occurs later in S phase.”
Given below are two Statements: Statement I: Chromomes become gradually visible under light microscope during leptotene stage. Statement II: The begining of diplotene stage is recognized by dissolution of synaptonemal complex.
In the light of the above statements, choose the
correct answer from the options given below:
AI-generated explanation. Check against your textbook.
Explanation:
Statement I is true: chromosomes begin to condense during leptotene and become visible under light microscopy as threads. Statement II is false according to NCERT: the dissolution of the synaptonemal complex begins after the zygotene stage and is not used to define the onset of diplotene as per NCERT wording. Hence, the correct option is 4.
🧠 Did You Know?
In diplotene, chiasmata become visible as homologous chromosomes start to separate while remaining joined at crossover points.
💡 NCERT Memory Line:
Leptotene: chromosomes first condense; Diplotene: desynapsis begins with synaptonemal complex dissolution not used to mark diplotene onset in NCERT phrasing.