Answer:
Spindle fibers move chromosomes during cell division by attaching to chromosome arms and chromosome centromeres. A centromere is a specific region of a chromosome where duplicated chromosomes are joined. The identical, joined copies of a single chromosome are known as sister chromatids. The centromere is also where specialized protein complexes called kinetochores are found.
Explanation:
The correct answer is B. Thymus gland: enables immature lymphocytes to mature into T cells
Answer:
D
is the answer because as you see the percentage increase
Answer:
See explanation
Explanation:
According to the theory of evolution,species which are better adapted to their environment tend to survive and reproduce in a population passing on these favourable characteristics to their offsprings.
During sexual reproduction, genes can be arranged in new ways from chromosomal crossing over and recombination. This introduces new gene combinations(genotype) and ultimately variation in the population.
This variation may also lead to the observation of new phenotypes in the population.
<span>Too little is known about pre-Archean time, from the origin of Earth to 3.8 billion years ago, to divide that period into units.</span>
