Prokaryotic cells DO NOT have centrioles, cytoskeleton, cilia or vesicles but they DO contain a prokaryotic flagella.
hope this helps!
Answer:
Charles Darwin
Explanation:
Natural selection, most famously proposed by Charles Darwin, states that when presented with an environmental challenge, some individuals in a species will develop adaptations to face these challenges. Successful individuals will be more likely to mate and their offspring will inherit these adaptive traits, and will continue to pass for generations.
In this sense, plants face the challenge of the cold. Those that adapt to the cold will survive and reproduce, those that can't adapt to the cold will die. Eventually, only plants that can tolerate the cold will survive.
During fertilization, the encounter of gametes results in the fusion of their nuclei. The nucleus of the egg cell thus formed is therefore a mixture of the two nuclei.
So the parent will only give half of his chromosomes, so the child will have 50% of his chromosomes that resemble each of his parents.
Another factor that must be mentioned is the genetic recombination between the chromosomes that occurs during meiosis of the reproductive cells. Thus, this will give a heterogeneous chromosome resulting from recombination of the two chromosomes of each of its parents, and the child will have a unique combination chromosome but keeping the alleles of both parents.
Because the three-horned alien is heterozygous, we know that three must be dominant to four, because the gene for the three horns is "hiding" the gene for four horns. Therefore, the three-horned alien has the genotype Tt (T for three horns, and t for four horns). The four horned alien must be tt, because that is the only way that a recessive trait may be seen. If you solve the punnet square on a cross between Tt and tt, you end up with half three (heterozygous) and half four (homozygous recessive) it is a bit easier to explain with something a little "closer to home" if you want me to explain it again, just say so, I don't mind!
