What are two possible causes of mass extinctions?

What do you think the amino acid sequences for hemoglobin in plants was blank? A. Plants do not contain fat B. Plants contain a different form of hemoglobin then what is found in animals C. Plants do not have blood D.

Malnutrition is caused by the lack of of specific? A. protein B. mineral C. carbohydrate D. nutrient

When magma cools below the surface, what type of rock results?

Measure of an organisms's ability to survive and produce offspring relative to other members of a population

If you were standing under the tree which object would appear to be moving

How are all living thing made of cells

Which is am example of an internal stimulus? A) an increase in the amount of water available to a plant B) an artificial light attracts insects C) a decrease in oxygen levels in the blood during exercise D) a sudden change of air temperature

How dose one determine when an ecosystem is in balance

How does respiratory system relate to respiration making ATP?

What is the largest group of reptiles that ever lived?