Which best describes tetrad?
a. four chromosomes
b. two gametes
c. a haploid cell
d. a diploid cell

The option that describes tetrad the best is:

A. Four chromosomes

Explanation:

Tetrads are 4 spores that are united or attached after the spores of plants have combined themselves to create a new cell of life. Now, we are talking of spores that united to create a cell. So we are not talking about two different cells uniting. We are talking about the product of the union of these two cells or spores to create a cell that will start a new life.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.