What prevents sperm cells from traveling the entire distance to the egg?

Who was the first person to receive a heart transplant?

What is the layer of material found at the innermost part of wood?

Identify the literary device employed in the following sentence from Herman Melville's short story "Bartleby, the Scrivener".

What is a purpose of a buffer in the body? A) to prevent capillary action B) to prevent sudden changes in pH C) to prevent sudden changes in temperature D) to prevent the formation of surface tension

Which of the following is not a characteristic of all living things? a. growth and development b. movement c. the ability to sense and respond d. homeostasis e. metabolism

How a biologist's reseach can proceed from an idea to a published article

How many times do the nostrils of a frog open and close in one minute

What regulates the enzymes present in an organism A. Phenotype B. Genotype C. Proteins D. Carbohydrates

What is the importance of the excretory system?

What are four sources of minerals?