Which of the following statements about viruses is false?
A) They are obligate intracellular pathogens.
B) CTLs and NK cells provide protective immune effector functions.
C) They are very small uni-cellular microorgansisms.
D) They are generally visible only by electron microscope.

C) They are very small uni-cellular microorganisms.

Explanation:

Microorganisms are very small organisms which are not visible to naked eyes. They include bacteria, some protists, some fungi etc. Viruses are also very small pathogens which can infect all types of living organisms, from plants to animals to bacteria.

Viruses are traditionally not considered microorganisms because they behave like non living entities outside the host cell. They do not have a proper cellular structure. Most of them just have genetic material enclosed in a protein shell. They do not even perform normal metabolic functions like replication outside the hosts's body. Hence, they are not considered microorganisms.

humans, along with other animals and plants, have linear chromosomes that are arranged in pairs within the nucleus of the cell. the only human cells that do not contain pairs of chromosomes are reproductive cells, or gametes, which carry just one copy of each chromosome.

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.