Question

question 1 - 6
billy and johnny are brothers, but they do not look alike. which of the following factors contributed to this genetic variation?
○ cytokinesis and cloning
○ dna replication and mitosis
○ asexual reproduction and binary fission
○ crossing over and independent assortment

Explanation:

• Cytokinesis and cloning: Cytokinesis is the division of the cytoplasm. Cloning produces genetically identical copies. Neither contributes to genetic variation in the context of siblings like Billy and Johnny.
• DNA replication and mitosis: DNA replication is for making an identical copy of DNA. Mitosis produces daughter cells with the same genetic material as the parent cell. This does not lead to genetic variation in offspring.
• Asexual reproduction and binary fission: Asexual reproduction (like binary fission in some organisms) results in offspring with genetic material identical or very similar to the parent. No genetic variation in the sense of siblings from sexual reproduction.
• Crossing over and independent assortment: Crossing - over occurs during meiosis (formation of gametes). Homologous chromosomes exchange genetic material. Independent assortment means that chromosomes assort independently during gamete formation. These two processes in meiosis (which is involved in sexual reproduction) lead to genetic variation in offspring.

Answer:

crossing over and independent assortment