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How many of the given statements are inc...

How many of the given statements are incorrect?
A. Nucleolus and nuclear membrane disappear in prophase.
B. Synaptonemal complex formation occurs during zygotene.
C. The enzyme responsible for crossing over in pachytene is recombinase.
D. Chiasmata formation occurs in diakinesis.

A

One

B

Two

C

Three

D

Four

Text Solution

AI Generated Solution

The correct Answer is:
To determine how many of the given statements are incorrect, we will analyze each statement one by one based on our understanding of cell division, specifically meiosis. ### Step-by-Step Solution: 1. **Statement A: Nucleolus and nuclear membrane disappear in prophase.** - In prophase (specifically prophase I of meiosis), the nuclear envelope does indeed break down, and the nucleolus disappears. This statement is **correct**. 2. **Statement B: Synaptonemal complex formation occurs during zygotene.** - Zygotene is a stage in prophase I of meiosis where homologous chromosomes pair up and form the synaptonemal complex. This statement is **correct**. 3. **Statement C: The enzyme responsible for crossing over in pachytene is recombinase.** - During pachytene, crossing over occurs, and it is facilitated by enzymes, including recombinase. This statement is **correct**. 4. **Statement D: Chiasmata formation occurs in diakinesis.** - Chiasmata are formed during the diplotene stage of prophase I, not diakinesis. In diakinesis, the chromosomes are already separated, and the chiasmata are visible but not formed. Thus, this statement is **incorrect**. ### Summary of Findings: - **Correct Statements:** A, B, C - **Incorrect Statements:** D ### Conclusion: Out of the four statements provided, **only one statement (D) is incorrect**. ### Final Answer: **1 incorrect statement.** ---
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