Biology

Question 1

Acrosome

Answer 1

The large vesicle at the head of a sperm cell containing enzymes that degrade the ovum cell membrane to allow fertilization.

Question 2

Action Potential

Answer 2

A sharpe change in the membrane potential of neurons or muscle cells caused by a change in the selective permeability to Na+ and K+ using voltage=gated ion channels. Action potentials are all-or-nothing events.

Question 3

Adaptive Immunity

Answer 3

A highly specific form of immunity that develops in response to exposure to pathogens; consists of both humoral immunity and cytotoxic immunity.

Question 4

Adrenal Cortex

Answer 4

Synthesizes and releases corticosteroids. Glucocorticoids are stimulated by ACTH, whereas mineralocorticoids are stimulated by angiotensin II. Cortical sex hormones include androgens such as testosterone.

Question 5

Adrenal Medulla

Answer 5

Synthesizes and releases epinephrine and norepinephrine, which stimulate an increase in the metabolic rate and blood glucose levels.

Question 6

ACTH

Answer 6

Synthesized and released by the anterior pituitary, ACTH stimulates the adrenal cortex to synthesize and secrete glucocorticoids. ACTH is regulated by Corticotropin Releasing Factor (CRF), which is released by the hypothalamus.

Question 7

Afferent Neurons

Answer 7

Neurons that carry information to the central nervous system from the periphery. Also called sensory neurons.

Question 8

Aldosterone

Answer 8

A steroid hormone produced in the adrenal cortex that is responsible for reabsorption of sodium and water and excretion of potassium and hydrogen ions.

Question 9

Allantois

Answer 9

The embryonic membrane that contains the growing embryo’s waste products.

Question 10

Alleles

Answer 10

Genes coding for alternative forms of a given trait

Question 11

Amino Acid-Derivative Hormones

Answer 11

Hormones that are synthesized by modifying amino acids. Most of these hormones act via secondary messengers, while some act in a fashion similar to steroid hormones.

Question 12

Amnion

Answer 12

the innermost extraembryonic membrane; produces the amniotic fluid in which the growing fetus is suspended.

Question 13

Anterior Pituitary

Answer 13

Synthesizes and releases many vital hormones, including FSH, lutenizing hormone, adrenocorticotropic hormone, TSH, prolactin, endorphins, and growth hormone (FLAT PEG). This is under the hormonal control of the hypothalamus.

Question 14

Antidiuretic Hormone (ADH)

Answer 14

A peptide hormone, also known as vasopressin, that acts on the collecting duct to increase water reabsorption. It is produced by the hypothalamus and store in the posterior pituitary.

Question 15

Antigen

Answer 15

A substance that is bound by an antibody, causing an immune reaction.

Question 16

Appendicular Skeleton

Answer 16

The bones of the pelvis, the pectoral girdles, and the limbs.

Question 17

Archenteron

Answer 17

The central cavity in the gastrula stage of embryological development; it is lined by endoderm and ultimately gives rise to the adult digestive tract.

Question 18

Arteries

Answer 18

Vessels that carry blood away from the heart. These vessels are muscular and do not have valves.

Question 19

Ascending Limb of the Loop of Henle

Answer 19

Portion of the nephron NOT permeable to water. As the filtrate flows up the ascending limb through a decreasing concentration in the interstitial fluid, NaCl is first passively then actively removed from the filtrate, decreasing filtrate concentration.

Question 20

Atria

Answer 20

The 2 thin-walled upper chambers of the heart. The right atrium receives deoxygenated blood from the venae cavae, while the left atrium receives oxygenated blood from the pulmonary veins.

Question 21

Atrioventricular Valves

Answer 21

Valves located between the atria and the ventricles (tricuspid and mitral valves).

Question 22

Axial Skeleton

Answer 22

The skull vertebral column, ribcage, and hyoid bone.

Question 23

Axon Hillock

Answer 23

The portion of the neuron that connects the cell body (soma) to the axon. The impulses the neuron receives from all the dendrites are summed up at the axon hillock to determine whether or not an AP will be initiated.

Question 24

Bacteriophages

Answer 24

Viruses that can only infect bacteria.

Question 25

Bile

Answer 25

An alkaline fluid synthesized in the liver, stored in the gall bladder, and released into the duodenum. Bile aids in the emulsification, digestion, and absorption of fats.