Haploid describes a cell that contains a single set of chromosomes. The term haploid can also refer to the number of chromosomes in egg or sperm cells, which are also called gametes. In humans, gametes are haploid cells that contain 23 chromosomes, each of which a one of a chromosome pair that exists in diplod cells.
Answer:
A. the heterozygote advantage
Explanation:
Heterozygote advantage is the condition where the heterozygous individual has higher relative fitness than both homozygous dominant and homozygous recessive individual. This means that the heterozygote individual has higher chances of surviving than both the homozygous counterparts. Sickle cell anemia is a recessive inherited disorder in which oxygen carrying hemoglobin has an abnormal structure. Hence, the resultant RBCs are not spherical but have crescent sickle shape. The oxygen carrying capacity of such RBCs is drastically reduced but they are unaffected by malarial parasite due to their abnormal structure.
- A person with both the recessive genes for sickle cell would not be able to survive due to insufficient oxygen transport in body.
- A person with both the dominant genes would be free of sickle cell anemia but in case of malaria would not be able to survive as the normal RBCs would be hijacked by the parasite.
- A hetrerozygote would survive both in malaria and sickle cell condition since he has enough normal RBCs for oxygen transport but also has sickle cell RBCs which are unaffected by malarial parasite.
Natural selection played a role by eliminating the snakes that had different colored bands. Those snakes with bands with different colored bands were most likely eaten because animals knew they didn't resemble the poisonous snake.
