Answer:
a. Comparative molecular studies trace our earliest genetic material to Africa
Explanation:
With the development of the genetics we have been able to come to new findings or confirm some suspicions when it comes to the origin of the humans. The genetic analyses of the human DNA and the other hominids that have died out, as well as out closest ''cousins'' in the animal kingdom, have shown that the earliest human ancestors have evolved in Africa. Over time, as the conditions allowed it, the hominids started to migrate out of Africa and gradually started to settle all around the planet.
<span>Chlorophyll is essential in photosynthesis, allowing plants to absorb energy from light. Chlorophylls absorb light most strongly in the blue portion of the electromagnetic spectrum as well as the red portion.
The absorption spectrum of chlorophyll a alone underestimates the effectiveness of certain wavelengths in driving photosynthesis. This is partly because accessory pigments with different absorption spectra are also photosynthetically important in chloroplasts and broaden the spectrum of colors that can be used for photosynthesis.</span>
The answer is A, water enters threw the roots not the leaves
Answer:
Yes...This is an example of speciation by natural selection
Explanation:
As we know that natural selection always promote those evolutionary changes that are necessary. Changes that happen in chromosome number always promote with a specie that is closely related to the parent specie and produce fertile off-springs. These new generations are most adaptable and can survive in the environment more efficiently than the previous ones.
Additionally, other than natural selection, speciation can also happen as a result of random mutations, genetic drift and by means of artificial selection as well. But the natural likelihood of all these is probably low as compared to that of natural selection.
Answer:
True
Explanation:
The Drosophila like the mammals possess X and Y chromosomes but as in males in which the XX is female and XY is male, the sex In Drosophila is not determined by the presence of Y chromosomes as a male determining factor are present on the autosomes.
However, the Y chromosome is important for males as they are involved in the formation of the sperms therefore the presence of Y is important. In the given question if the allele is present ion the Y chromosome which can reduce the size therefore the allele is passed on to the males only ans no females.
Thus, true is the correct answer.
the fly is female (Bridges 1921, 1925). Thus, XO Drosophila are sterile males. In flies, the Y chromosome is not involved in determining sex. Rather, it contains genes active in forming sperm in adults.
