Match each cell type with its description.
killer cell
a. stains with basic dye methylene blue, has large amounts of histamine in granules, and facilitates allergic responses and inflammation

b. stains with acidic dye eosin, has histamine and major basic protein in granules, and facilitates responses to protozoa and helminths

c. recognizes abnormal cells, binds to them, and releases perforin and granzyme molecules, which induce apoptosis

d. large agranular phagocyte that resides in tissues such as the brain and lungs

1. A natural killer cell identifies unusual cells, combines with them, and discharges perforin and molecules of granzyme that stimulates apoptosis.  

2. A basophil comprises huge concentrations of histamine in granules, gets stain with basic dye methylene blue, and helps in inflammation and allergic reactions.  

3. A macrophage refers to a huge agranular phagocyte, which is found within the tissues like lungs and brain.  

4. An eosinophil comprises histamine and major basic protein in granules gets stain with acidic dye eosin and helps in reactions against the helminths and protozoa.  

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: