Explanation:
HIV attacks a specific type of immune system cell in the body. It's known as the CD4 helper cell or T cell. When HIV destroys this cell, it becomes harder for the body to fight off other infections. When HIV is left untreated, even a minor infection such as a cold can be much more severe.
Answer:
They lack a nucleus, but they do have ribosomes.
Explanation:
Prokaryotes are unicellular organisms that lack organelles or other internal membrane-bound structures. Therefore, they do not have a nucleus, but, instead, generally have a single chromosome: a piece of circular, double-stranded DNA located in an area of the cell called the nucleoid.
It could be a common ancestry among organisms.
Answer:
False
Explanation:
The most specific feature of cardiac muscles is the presence of intercalated discs. Intercalated disc connects the ends of cardiac muscle fibers to one another. The discs have desmosomes and gap junctions. The function of desmosomes is to hold the cardiac fibers together. The gap junctions of cardiac fibers allow muscle action potentials to spread from one cardiac muscle fiber to another. These gap junctions have tubular connexons that form channels and connect the cytosol of adjacent cardiocytes to allow the flow of ions and spread of action potential from one cell to another.
