2. all of the following are true of crossing over, except
crossing over occurs immediately after an egg is fertilized.
homologous chromosomes exchange genetic material.
crossing over results in unique combinations of alleles.
crossing over occurs during meiosis i.
crossing over occurs only in cells destined to become sperm or egg.

Option (1)

Explanation:

Meiosis is also known as reduction division. Meiosis is the process of cell division by which a  parent cell divides to give four daughter cells each with half number of chromosomes.

Crossing over may occur during meiosis I of the cell cycle. Crossing over will not occur in the cells immediately after the fertilization of egg and zygote restores the original number of chromosomes.

Thus, the correct answer is option (1).

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.