Answer:
1 - Malaria
2- Typhoid fever and Tuberculosis
Explanation:
In case of malaria, the causal microorganism is Plasmodium falciparum, which target red blood cells of host. In humans who have defective sickle cell allele, have abnomral shaped red blood cells. So microorganism does not able to attach to abnormal shaped RBCs thus humans having sickle cell allele are more resistant to death caused by malaria.
In cystic fibrosis, mutation on that gene which encodes a protein known as cystic fibrosis transmembrane conductance regulator (CFTR).
Normally Salmonella typhi (bacteria responsible for typhoid fever) enters into intestinal cells by attaching with CFTR receptor. Carriers of cystic fibrosis mutant gene, have abnormal CFTR thus reduced rate of entry of bacteria into carriers.
Normally Mycobacterium tuberculosis (bacteria responsible for tuberculosis) adds sulfate in its cell walls. In carriers of cystic fibrosis, arylsulfatase B activity is reduced which incorporates sulfate. Thus reduced arylsulfatase activity makes bacteria unable to add sulfate in its cell walls thus decreases their virulence to carriers of cystic fibrosis.
Answer: c. Part of an ecosystem
Explanation: the fish, crustaceans, molluscs and bacteria are part of a community, but sand is not. Each of those species is part of a population.
Answer:
A generation is "all the people who are born and lived at about one time collectively" and is also defined as "the average period in which children are born and grow up, becoming adults and start having children of their own" "currently approximately thirty years"
What system are we talking about? Context is needed... water cycle, cells, etc?
