Answer:
a
Explanation:
Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.
Answer:
knirps (a gap gene)
wingless (a segment-polarity gene)
kruppel (a gap gene)
even-skipped ( a pair-rule gene)
hunchback (a gap gene)
hedgehog (a segment-polarity gene)
Explanation:
The gap, segment-polarity and pair-rule genes play central roles in controlling embryonic development of arthropods. In the first place, the gap genes are associated with the formation of contiguous body segments, thereby mutations in these genes result in gaps in the normal body plan of the embryo. For example, in <em>Drosophila melanogaster</em>, mutations in the <em>knirps, Krüppel </em>and<em> hunchback</em> genes result in deletion of body segments. These genes are also known to regulate segment polarity genes, which determine the polarity of the embryonic parasegments by modulating Wnt and Hedgehog signaling pathways. Finally, the pair-rule genes work together with gap genes to control embryonic development of alternating body segments.
Answer:
Populations are all the individuals of a species living in a defined area.
Answer:
The hardness rating is 4.
Explanation:
Calcite sits at a hardness rating of 3 and is very easily scratched with a knife and/copper coin. This is where most Marbles, limestones, travertines, rate.
Meanwhile, Fluorite sits at hardness 4 and can be scratched by a knife.
Passive transport molecules move molecules with their concentration gradient
