Which processes lead to most genetic variation in sexually reproducing organisms?

Question

Select all that apply.

random fertilization
crossing over
independent assortment of chromosomes in meiosis
cytokinesis
Request Answer
Part B
Which of these gametes contains one or more recombinant chromosomes?
Gamete arrangement after meiosis with a crossing over. A cell contains one large blue chromosome, one large red chromosome, one small blue chromosome, and one small red chromosome. This cell can form 8 types of gametes, 5 of them are labeled A through E. Gamete A contains 1 long blue and 1 short blue chromosomes. Gamete B contains 1 long blue and 1 short blue chromosomes; both have red ends. Gamete C contains 1 long red and 1 short red chromosomes; both have blue ends. Gamete D contains 1 long red and 1 short red chromosomes. Gamete E contains 1 long red and 1 short blue chromosomes.

B and C
A and C
A and B
D and E
A and D

Answer 1

Part A: The processes that lead to most genetic variation in sexually reproducing organisms are:

• Random fertilization
• Crossing over
• Independent assortment of chromosomes in meiosis

These three processes contribute significantly to genetic diversity.

Part B: To identify which gametes contain one or more recombinant chromosomes, we need to look for gametes that have chromosomes with a mix of genetic material from the parent's chromosomes due to crossing over.

From the description:

• Gamete A: Contains 1 long blue and 1 short blue chromosome. (No recombination; no red ends)
• Gamete B: Contains 1 long blue and 1 short blue chromosome, both with red ends. (Recombinant)
• Gamete C: Contains 1 long red and 1 short red chromosome, both with blue ends. (Recombinant)
• Gamete D: Contains 1 long red and 1 short red chromosome. (No recombination)
• Gamete E: Contains 1 long red and 1 short blue chromosome. (Recombinant)

Thus, the gametes that contain one or more recombinant chromosomes are B, C, and E.

However, if we are to choose from the provided options that contain one or more recombinant chromosomes:

• B and C would be the best choice, as both contain recombinant chromosomes.

So, the answer for Part B is B and C.