Answer:
It is a quantitative observations
Answer:
6, 3, 4, 5, 7, 2, 1
Explanation:
Here, speciation occurs because the original butterfly population gets separated into two populations, each facing a different set of environmental conditions. Initially, there was just a single population of butterflies in the valley and all butterflies were able to mate with each other. A fire destroyed their habitat so they had to migrate to other areas. Some butterflies migrated to eastern side of mountain and some to western side of mountain.
Now there were two butterfly populations and they faced different environment from each other. Over the time, the populations adapted to their local surroundings and started to accumulate changes in their genome. Their gene pools started to separate from each other. Eventually they evolved into two different species. When their old habitat was restored in the valley, they returned once again. However, this time they were not able to interbreed because they were now two different species.
Answer:
crossing over, process in genetics by which the two chromosomes of a homologous pair exchange equal segments with each other. Crossing over occurs in the first division of meiosis . At that stage each chromosome has replicated into two strands called sister chromatids. The two homologous chromosomes of a pair synapse, or come together. While the chromosomes are synapsed, breaks occur at corresponding points in two of the non-sister chromatids, i.e., in one chromatid of each chromosome. Since the chromosomes are homologous, breaks at corresponding points mean that the segments that are broken off contain corresponding genes , i.e., alleles. The broken sections are then exchanged between the chromosomes to form complete new units, and each new recombined chromosome of the pair can go to a different daughter sex cell. Crossing over results in recombination of genes found on the same chromosome, called linked genes, that would otherwise always be transmitted together. Because the frequency of crossing over between any two linked genes is proportional to the chromosomal distance between them, crossing over frequencies are used to construct genetic, or linkage, maps of genes on chromosomes. Mutations , temperature changes, and radiation all affect crossing over frequency. Under the microscope, a crossover has the appearance of an X and is called a chiasma.
Explanation:
How
often an allele occurs in the gene pool is allele frequency.
<span>Allele
frequency defines how common an allele is in a population. It can be calculated
by counting how many times the allele appears in the population and then
dividing by the total number of copies of the gene.</span>
