Answer:
The correct answer is option d) age of either or both parents.
Explanation:
Genetic variation is the difference in nucleotide sequences between individuals organisms within a particular population. Variation can occur either in germ cells that are sperm and egg or in somatic cells or in both.
Random fertilization of egg and sperm can lead to genetic variation is every germ cell has a different set of chromosomes. Independent assortment of chromosomes is also the same as random fertilization as it is also random. Crossing over of homologous chromosomes is one of a major source of the genetic variation as it forms a new set of chromosomes.
Thus, the correct answer is option D) age of either or both parents.
Answer:
Structures that are still present but currently serve little to no purpose
Explanation:
<em>Vestigial structures/organs are general defined as structures/organs that are present but poorly developed without any functional use in the present living organisms but thought to have been fully developed and functional in their ancestors.</em>
Fully developed and functional organs gradually become less developed and non-functional across generations as the environment keeps changing and organisms found lesser use for the organs. An example includes the <u>caudal vertebrae</u> found in man which is kind of useless but thought to have been fully developed and functional in the ancestors of man - the monkeys.
<u>Vestigial organs are often used as one of the morphological evidence of the evolution of living organisms.</u>
<span>Gametogenesis is the process of forming gametes (by definition haploid, n) from diploid cells of the germ line. Spermatogenesis is the process of forming sperm cells by meiosis (in animals, by mitosis in plants) in specialized organs known as gonads (in males these are termed testes).</span>
A similarity in both recrystallization and replacement modes of preservation is that delicate tissue and organs are not preserved.
<h3>What are recrystallization and replacement modes of preservation?</h3>
Recrystallization is a mode of preservation of fossils in which the internal structure of the fossils is changed by addition of more minerals to form larger crystal of the same material.
Replacement is a mode of preservation in which new material replaces the original material in the fossil.
In both methods of preservation, delicate tissue and organs are not preserved.
Therefore, a similarity in both recrystallization and replacement modes of preservation is that delicate tissue and organs are not preserved.
Learn more about fossils preservation at: brainly.com/question/2023023
#SPJ1
