Answer:
circulatory system
Explanation:
carries oxygen, water, and nutrients to cells throughout your body. Wastes from the cells are eliminated by your respiratory system, your excretory system, and your skin. Your nervous system controls all these activities with electrical impulses.
Answer:
Nucleus
Explanation:
Prokaryotes are the organism that came earlier than eukaryotes on this earth. These prokaryotes do not have a nucleus and other membrane-bound organelles like chloroplast, mitochondria, Golgi apparatus, endoplasmic reticulum, etc.
So as prokaryotes lack membrane-bound organelle their genetic material is not enclosed in the nucleus therefore their genetic material remains in the cytoplasm of the cell while eukaryotes have membrane-bound nucleus in which their genetic material are present.
So the nucleus is the major organelle that prokaryotes are missing that eukaryotes have.
Answer: a. Genetic recombination (crossing over)
b. Can also be explained in terms of crossing over
c. Non disjunction of homologous chromosomes in meiosis 1
Explanation:
The process that allows for the transfer of both the paternal and maternal materials to is the crossing over process that takes at meiosis 1 changing them to secondary spermatocytes. While they are still primary spermatocytes, they are still diploid cells having both the maternal and paternal chromosomes. But since the spermatozoon is an haploid cell, it is able to retail some of both parents chromosome by the crossing over event which takes place between homologous paternal and maternal chromosomes allowing them to exchange materials. Thus the chromosomal contents of the primary spermatocyte differs from that of the spermatozoon.
C. This can occur as a result of the one of the homologous chromosome pair refusing to separate at meiosis 1 with one gamete containing 4 chromosomes/8 sister chromatids and the second having 2 chromosomes/4 sister chromatids.
