Answer:
b. 2
Explanation:
Humans have typically 23 pairs of chromosomes. Each pair is composed of a chromosome from the mother and another from the father. A specific locus in a chromosome is composed of two alleles. An allele inherited from the mother and the other allele inherited from the father.
The answer is B, because salt water has lots salt, and little water. The cells lose their water content and fill up with salt, causing ti to collapse.
Answer:
The placenta is a unique vascular organ that receives blood supplies from both the maternal and the fetal systems and thus has two separate circulatory systems for blood: (1) the maternal-placental (uteroplacental) blood circulation, and (2) the fetal-placental (fetoplacental) blood circulation. The uteroplacental circulation starts with the maternal blood flow into the intervillous space through decidual spiral arteries. Exchange of oxygen and nutrients take place as the maternal blood flows around terminal villi in the intervillous space. The in-flowing maternal arterial blood pushes deoxygenated blood into the endometrial and then uterine veins back to the maternal circulation. The fetal-placental circulation allows the umbilical arteries
Explanation:
Natural selection is nature’s way of keeping the best fit-to-live things alive, and so on continue to the next generations.
For example, if a rabbit has a limp, it is bound to be out run and eaten by a predator relatively early in its life (unless it is extremely lucky.) Because of this, it is unable to reproduce, and there genes that it contained to have its limp are unable to spread through inheritance. Natural selection goes both ways. For example, if a hawk has very god vision, it will be able to scope out its prey easily, so it will thrive. Therefore, when it produces offspring of its own, its trait of good eyesight will pass on to its offspring.
So, as enough time goes on, the bad traits will be weeded out and the good ones will remain.
Answer:
bed rock
Explanation:
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