I’m too certain but i believe the answer is recreation
Interphase: Chromosomes duplicate, and the copies remain attached to each other.
Prophase: In the nucleus, chromosomes condense and become visible. Spindle fibers begin to form.
Prometaphase: The nulcear membrane breaks apart, and the spindle starts to interact with the chromosomes.
Metaphase: The copied chromosomes align in the middle of the spindle.
Anaphase: Chromosomes separate into two genetically identical groups and move to opposite ends of the spindle.
Telophase: Nuclear membranes form around each of the two sets of chromosomes, they begin to spread out, and the spindle begins to break down.
Cytokinesis: The two cells split into two daughter cells, each with the same number of chromosomes as the parent cell.
Answer:
The variation might occur in the population that leads to the evolution of the species. This variation may occur due to natural selection, mutation or recombination.
The variation might change the genotype and allelic frequency of the population and might also change the phenotype of the individual in the population. The breeding adults of the left mouthed in 1981, 1987 and 1990 shows variation and was equally opposite phenotype which is more common in the population.
Answer:
Most people experience increased infant mortalities at high altitudes due to the inability of the mother to provide sufficient oxygen to the developing fetus but now variation in the DNA sequence in the people that lives at higher altitudes like in Tibetans allow normal level of infant survival at high altitudes.
This variation occurred in the EPAS1 gene in the Tibetan population that is responsible for delivering oxygen more efficiently to the fetus. This nucleotide variation is also present in low landers of Beijing but natural selection selected the variant gene in Tibetan people because they require this mutated gene for their survival.
So the population passed this variant gene in next-generation, therefore, inheritance allowed the spreading of the mutated gene to the next generation therefore by natural selection and inheritance a mutated gene spread through a human population that had just begun living high in the mountains.