Of what is this an example? a puppy’s cells have two sex chromosomes that are the same.

homozygous dominant

homozygous recessive

heterozygous

female

female

Explanation:

In dogs, sex determination is done by XY-system. The X and Y chromosomes are known as sex chromosomes. Karyotype of males is represented by XY as males have one X and Y chromosome, while karyotype of females is represented by XX as females have both X chromosomes.

Hence, if a puppy cell's have same sex chromosomes, these cells must have two X chromosomes, which represents a female. Thus, the correct answer is option). female.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.