Answer:
thyakoid discs
Explanation:
the light reaction takes place in the thyakoid discs, there H20 is oxidised and O2 is released
Answer:
D) a genetic bottleneck
Explanation:
Genetic bottleneck refers to the sudden reduction in the population size due to some adverse climatic factors such as natural calamities. It changes the allele frequencies since the survivor population mostly have different allele frequencies than the original population.
In the given example, an earthquake kills 98% of the squirrels. The survivor population exhibits different allele frequencies for the gene responsible for the thickness of stripes. Therefore, it represents a genetic bottleneck.
The sugar and phosphate portion of the nucleotides are found as segments of the rails on the DNA twisted ladder.
Explanation:
In the majority of cases, the extra copy of chromosome 21 comes from the mother in the egg.
In a small percentage (less than 5%) of cases, the extra copy of chromosome 21 comes from the father through the sperm.
In the remaining cases, the error occurs after fertilization, as the embryo grows.