How many of the animal phyla include single celled animals?

Biologists think early eukaryotic cells might have formed from prokaryotic cells that A. had a flexible outer cell membrane instead of a stiff cell wall B. gradually developed a stiff outer cell wall for protection c.

Suppose that a snake handler bitten by a particular venomous snake species was treated with antivenin. Why might the same treatment for a second bite from a similar snake have different results?

The 30 trillion or so cells in your body require a continuous supply of oxygen and nutrients and an unending removal of waste materials. the blood carries these materials in the body's circulation within a series of closed tubes, called

What is the purpose of the earth's inner core?

Why is salt not allowed to pass through the cell membrane?

What is the best method of suicide

What happens to the water contained in the materials that pass into the large intestine?

What is reconstrutive memory

What percentage of human sperm cells carry an x chromosome?

After a major environmental change, what happens to species that do not adapt or move? i need it fast