There are four mechanisms that can cause changes in the frequencies of genes in populations: mutation, migration, genetic drift, and natural selection. All four are mechanisms of evolutionary change. What is genetic drift? A) In a population, it is the changes in allelic frequencies of a gene that are due to chance.
B) A random error/change in the DNA sequence. These may be inherited or occur in cells during the lifetime of the organism
C) Also known as gene flow. It is any movement of individuals and/or the genetic material they carry, from one population to another.
D) There is variation in any population differential reproduction occurs and over time a more advantageous trait exists in the population.

a. seed plant structure. 1. the three main plant organs are roots, stems, and leaves. a fourth kind of tissue, meristematic tissue, is responsible for plant growth. meristematic tissue is the only plant tissue that produces new cells by mitosis. plants can lose water out of their leaves as they exchange gases with the air

explanation:

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.

you know they are heterozygous for a trait because they have it as jj or jj.