Wastes and dead organisms must be broken down in order for their components to be used again.

What happens when cold air approaches a body of warm air?

Which of the following best supports the scientific theory of evolution

Hormones are chemical molecules produced by endocrine glands. One such endocrine gland is the thyroid gland, which synthesizes the thyroid hormone, which in turn affects the heart muscles.

Are plant and animal cells generally the same size

Proteins can vary in size from approximately 40 to 34,000 amino acids. a. why is there a lower limit to the size of proteins? b. why is there an upper limit to the size of polypeptides?

Which organelle is not found in plant cells? A) vacuoles B) mitochondria C) chloroplast D) centrioles

Gina is driving her car down the street. She has a teddy bear sitting on the back seat. A dog runs in front of Gina's car, so she quickly applies the brakes.

The term enzymes, was first used in 1878. The term is derived from a Greek word that means in yeast because the yeast cells were first to reveal enzyme activity in living organisms.

The pituitary gland is controlled by sex hormones? 1. true or 2. false

Which function of the skeletal system would be especially important if you were in a car accident? fat storage protection of internal organs storage of minerals facilitation of movement