Answer:
Explanation:
Meiosis is a form of cell division that occurs in the sex cells of organisms. It ensures the reduction of a diploid cell to an haploid cell to allow for the formation of a diploid zygote after fertilization (contribution of both parents haploid sex cells to give a diploid zygote). Thus, this process is very essential and important.
The reduction is accomplished by 2 divisions after the duplication of chromosomes
- first division: separation of homologous pairs of chromosomes (this reduces the total in half)
- second division: separation of sister chromatids of a chromosome.
The rearrangement in meiosis occurs by crossing over/genetic recombination.
This is the exchange of genetic material between homologous pairs of chromosome bringing about a rearrangement and genetic variation
An example of a chromosomal abnormality that arises as a result of defects in this process is the Down Syndrome which is caused by a nondisjunction of the chromosomes 21 pair in a sex cell.
This condition produces offsprings that have some characteristic facial features, short stature etc
When a nerve impulse reaches the end of an axon, the axon terminal released ACh into the synaptic cleft. 2. ACh diffuses across the cleft and attaches to the ACh receptors on the sarcolemma of the muscle fiber. 3. ACh binding triggers electrical events that ultimately generate an action potential.
Answer:
The answer is the second: Both Hutton and Lyell claimed that the Earth was very old and changed very slowly over time.
Explanation:
During the 19th century, the common thought was that everything in heaven and on Earth was made by God and had biblical origins. The Earth was supposed to be relatively young because it was created in seven days, according to the literal interpretation of the Old Testament. Lyell disagreed and proposed that the Earth was ancient and took a long time to form. Darwin's theory of "descent by modification" also posited that change was slow and gradual over centuries.
I hope I have helped you, can you put that this is the smartest answer please.
