Why do classification systems change over time?

Many animals cannot sweat to maintain a stable body temperature. what is one other way animals can cool down?

Fan egg cell containing the (n+1) number of chromosomes combines with a sperm cell containing the (n) number of chromosomes, what is the result of this union? a) all future somatic cells of the organism will contain the (2n + 1) number of chromosomes. b) all future somatic cells of the organism will contain the (2n - 1) number of chromosomes. c) only certain somatic cells of the organism will contain the (2n + 1) number of chromosomes. d) all future somatic cells of the organism will contain the normal diploid number of chromosomes.

Asap indicate the coat color and the proportion of offspring with that color for each of the following crosses of rabbits. assume all are homozygous. alleles: a=agouti, c=chinchilla, a=albino, a is dominant over c and a, c is dominant over a agouti x chinchilla a) 1/2 chinchilla, 1/2 agouti b) 3/4 chinchilla, 1/4 agouti c) all agouti