Salmon fish hatcheries add a harmless perfume (morpholine) to a stream when they release young fish. when the fish mature, they attract them back to the home stream by using this chemical (in nature the fish smell the unique odors of soil and trees along the home stream). in effect, the hatchery biologist is using
a. the fish's inborn instincts to relocate its own stream.
b. the fish's inborn instincts to relocate its own stream.
c. an experiment based on the ability of fish to learn by trial and error.
d. chemotropisms.

The options are not complete

Salmon fish hatcheries add a harmless perfume (morpholine) to a stream when they release young fish. When the fish mature, they attract them back to the home stream by using this chemical (in nature the fish smell the unique odors of soil and trees along the home stream). In effect, the hatchery biologist is using

A. the fish's inborn instincts to relocate its own stream.

B. the fish's inborn instincts to relocate its own stream.

C. an experiment based on the ability of fish to learn by trial and error.

D. chemotropisms.

E. Imprinting

E. Imprinting

Explanation:

Imprinting is kind of rapid responsive learning occurring at a particular stage in life, whereby the organism establishes a behavioral pattern such as recognition or attraction to it kinship or a substitute.

In the Salmon fish hatcheries(a building where hatching of fish or poultry eggs is artificially controlled for commercial purposes), the addition of a harmless perfume (morpholine) to a stream when they release young fish is a substitute to the Salmon fish kinship. When the fish mature, i.e at a particular stage of their life, they attract them back(a form of attraction to it own kind) to the home stream by using this chemical.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.

the animal that would be cutest if scaled down to the size of a cat? elephant