Question

question 1
why are no two gametes exactly alike genetically?
answer
because each gamete undergoes a slightly different version of mitosis during its formation
because each gamete has chromosomes produced through crossing over
because each gamete has a different combination of parental chromosomes
because cell membranes are unique for each gamete
because each gamete has a different combination of parental chromosomes that is the result of both crossing over and independent assortment
i dont know yet

Explanation:

Gametes are formed through meiosis. Crossing - over (exchange of genetic material between homologous chromosomes) and independent assortment (random distribution of homologous chromosome pairs during meiosis) occur during meiosis. These two processes lead to genetic variation among gametes. Each gamete has a unique combination of parental chromosomes as a result of both crossing - over and independent assortment.

• Mitosis is not involved in gamete formation (gametes are formed by meiosis), so the first option is wrong.
• Just mentioning crossing - over (second option) or just a different combination of parental chromosomes (third option) is not comprehensive enough as both crossing - over and independent assortment contribute.
• Cell membranes being unique has no relation to genetic differences among gametes (fourth option is wrong).

Answer:

Because each gamete has a different combination of parental chromosomes that is the result of both crossing over and independent assortment.