Answer:
C.
Explanation:
The biggest difference between the two is what the blastropore develops into
Answer- B. Neuron
Hope this helps :)
Answer:
B) Heterozygotes are less susceptible to the malaria parasite, so there is an advantage to being heterozygous.
Explanation:
Sickle cell anemia is a recessive condition in which the red blood cells (RBCs) become sickle shaped. Due to the abnormal shape they are not able to transport oxygen efficiently which proves lethal for the person. Both, homozygous dominants and heterozygotes survive.
However in African countries with high rate of malaria, heterozygotes are selected over the dominant homozygotes. Dominant homozygotes have all normal RBCs which make them susceptible to malarial parasite since RBC is the host cell for it.
Heterozygotes produce some normal RBCs and some sickle shaped. Malarial parasite is not able to attack sickle shaped RBCs because of its unusual shape. So heterozygotes are less susceptible to malaria. Since they also have some normal RBCs, they are not affected much by sickle cell anemia too. Hence, heterozygotes evade both sickle cell anemia and malaria and heterozygous is the most advantageous genotype in this case.
The definition to parasitism is "the practice of living as a parasite in or on another organism." (Wikipedia). Therfore the answer to this is Ticks live on and drink blood from a cow, because this is the only option where an organism is living directly off another organism.
Hope I was most helpfull to you!