Answer:
Genetic drift
Explanation:
Genetic drift describes random fluctuations in the numbers of gene variants in a population. Genetic drift takes place when the occurrence of variant forms of a gene, called alleles, increases and decreases by chance over time. These variations in the presence of alleles are measured as changes in allele frequencies.
They are both biotic factors because they affect living organisms. The abiotic factor a lion and deer needs is water because they need to stay hydrated but water is not living . Deers eat plants, plants are known as biotic factors too. And lions eat their prey which are living animals and once they are preyed upon they are still considered biotic because they were once living before getting consumed by the lion.
<span>Mannitol reduces the intracranial hypertension in patients with head injury. this chemical which is a sugar- alcohol lowers the viscosity of the blood and thus reducing the blood volume. Head injury may lead to increased intracranial pressure and volume. It is also believed that mannitol acts by reducing brain water.</span>
Answer:
Explanation:
Bicoid gene is the maternal effect gene whose protein concentration gradient patters the anterior-posterior axis in Drosophila embryogenesis. It was the primary protein that is demonstrated to act as a morphogen. Morphogens are proteins whose concentration gradient will affect the developmental fate of the surrounding region.
The specified bicoid gene is the one which codes for bicoid protein. This protein is being existing in a gradient manner in the egg and thus its concentration is higher at the anterior end and lower in posterior end.
This bicoid protein is responsible for the stimulation of the development of the anterior end.
The posterior region (including the hindgut) expands and extends towards the anterior pole along the dorsal side of the embryo. At this time, segments of the embryo become visible, creating a striped arrangement along the anterior-posterior axis.
