I think the answer is d not quite sure tho
Sister chromatids have different alleles although carry same genes on same loci. So if it doesn't happen so, like if there are same alleles on sister chromatids then there is a problem in its formation. i.e., male and female alleles haven't contributed equally ( may be an error during their segregation process ). And obviously it doesn't happen in a real cell so we must understand this point. Because normally whenever it happens there's one half from the male and one half from the female. (i.e. maternal and paternal alleles contribute equally).
I hope you get the answer!!!
The human gene for insulin production is identified and removed using enzymes called restriction enzymes. The same restriction enzymes are used to cut open a plasmid (a small, circular section of DNA).
Natural Changes That Can Affect an Ecosystem. Wind, rain, predation and earthquakes are all examples of natural processes which impact an ecosystem. Humans also affect ecosystems by reducing habitat, over-hunting, broadcasting pesticides or fertilizers, and other influences.
They are different because endocrine glands has tiny amount of hormone directly into the bloodstream . While exocrine glands secret their products on to epithelial
