Answer:
May be Nutritional but no sure
Homozygous recessive is when an individual carries two identical copies of the recessive gene. An individual that is homozygous recessive for both traits will have the genotype, aabb.
I think the answer here is neurons, the nerve cells
Using a slow- and fast-growing variant of bamboo, Wei and colleagues looked at cell division, growth, and gene expression (through transcriptomics, which measures all the genes being expressed by an individual) to discover which genes may be responsible for fast growth in bamboo. They found that the slow-growing variant had reduced expression of genes relating to cell wall construction, the plant hormone auxin (important for cell growth and cell division), and had irregular cell growth and cell walls. Wei and colleagues suggest that a reduced ability to produce and perceive auxin, combined with a weakened cell wall, are responsible for the slow growth seen in the bamboo variant.
<h2>Answer:</h2>
The two reasons are given below:
- Natural selection.
- Lack of food
<h3>Explanation:</h3>
Natural selection is the phenomenon of the evolution in which the organisms able to fit in the changing environment survive while other organism died. Hence the survival if the fittest and then these organisms. Further reproduce to give birth organisms more fit to the changing environment.
The long neck giraffe survive but short neck died. So the population of long neck increased while short neck go extinct.
Other reason is the change of food resource. The food resource change from grass to long trees.
