Answer:
6==. During spermatogenesis, four sperm result from each primary spermatocyte, which divides into two haploid secondary spermatocytes; these cells will go through a second meiotic division to produce four spermatids
One big reason for this is because individuals of the same species often have to fight over shared resources (this means shared food and shared environment).
Because they fight over a limited amount of space and food, competition between individuals within one species can be present and very tough.
On the other hand, having members of different species also possibly means different territories and different food sources. A lion has no quarrel with dolphins, while it can have a lot of fights with lions from different prides (large group of lions).
Charles Darwin noticed that among the same species there were variations in traits based upon geographical location. These changes may have evolved from climate differences, predator/prey relationships and food sources. This particular experiment was intended to duplicate natural selection by demonstrating the concepts with artificial selection. The result was that over time, new traits could be bred for. Although there may be more than one correct answer here, the best answer is the first; desirable traits can be selected and bred in offspring.
Answer:
Most amphibians can breathe both through cutaneous respiration (through their skin) and buccal pumping - though some also retain gills as adults. Some aquatic salamanders (and all tadpoles) have gills and can breathe underwater thanks to them. The Mexican axolotl, for example, never loses its gills.
Answer:
They are codominant
Explanation:
There are 3 different alleles: IA, IB and i - IA and IB are codominants, i is recessive. Codominance means neither allele can mask the expression of the other and both alleles A and B are expressed in the blood type.
