What is a source of genetic variation?

A adaptation

B mutation

C respiration

D transpiration

The most successful of the invertebrate phyla with respect to the numbers of species is a. Annelida. b. Arthropoda. c. Mollusca. d. Echinodermata. e. Nematoda.

An individual eats a hamburger. Which two systems must interact to transfer the nutrients in the hamburger to human muscle tissue?

Major consequence of ozone depletion is that a. solar energy will become ineffective. b. more harmful uv rays will reach the earth's surface. c. acid rain will increase. d. certain parts of the earth will become over-vegetated.

Explain the importance of excretion in human being.

One difference between bacteria and viruses is

Describe Three functions of reproduction

What is the primary function of the respiratory system? Question 5 options: 1) Transportation of blood 2) Oxygenate blood 3) Absorption of nutrients 4) None of the above

7 the organisms felis catus and felis silvestris do not belong to the same -

Hich equation shows a disaccharide with the monosaccharides that make it up?

Which of these vessels returns blood to the left atrium of the heart? A) pulmonary veins B) coronary sinus C) superior vena cava D) pulmonary trunk