AP Bio Chap. 41

Question 1

Contractile Vacuoles

Answer 1

Organelle that collects and then expels any excess water that moves into the cell by osmosis.

Question 2

Flame Cells

Answer 2

Cells contain a tuft of cilia that looks like a flickering flame when viewed with a microscope.

Question 3

Nephridia

Answer 3

Pair of tubular excretory organs.

Question 4

Uric Acid

Answer 4

Some enzymes in their blood convert ammonia to _________.

Question 5

Malpigian Tubules

Answer 5

Long, thin excretory organs that connect to and empty into a region of the gut. Solutes are pumped into it, along with water from osmosis.

Question 6

Urinary System

Answer 6

Filters water and solutes from their blood, then reclaims or excretes water and certain solutes as needed to maintain the volume and composition of the extracellular fluid.

Question 7

Kidneys

Answer 7

Filter blood.

Question 8

Urea

Answer 8

Nitrogen containing waste excreted in urine; forms in the liver when ammonia combines with CO2.

Question 9

Renal Cortex

Answer 9

Outer portion of the kidney, where nephrons begin.

Question 10

Renal Medulla

Answer 10

Inner portion of the kidney, nephron’s loop of Henle and collecting duct extend.

Question 11

Ureter

Answer 11

A urine-conducting tube from each kidney to the urinary bladder.

Question 12

Urinary Bladder

Answer 12

Stores urine until sphincter at its lower end opens and flows into the urethra.

Question 13

Urethra

Answer 13

Tube that drains the urinary bladder; opens at the body surface.

Question 14

Nephrons

Answer 14

Microscopically small tubes with a wall only one cell thick.

Question 15

Bowman’s Capsule

Answer 15

Nephron that is ballooned outward and folded back on itself to form a cup shape.

Question 16

Proximal Tubule

Answer 16

Past the capsule, the nephron twists a bit and straightens out as a __________.

Question 17

Loop of Henle

Answer 17

After extending down into the renal medulla, the nephron makes a hairpin turn, the _______.

Question 18

Distal Tubule

Answer 18

Nephron reenters the cortex and it twists again.

Question 19

Collecting Ducts

Answer 19

Distal tubule drains into ________.

Question 20

Glomerulus

Answer 20

Capillary bed inside Bowman’s capsule.

Question 21

Peritubular Capillaries

Answer 21

Thread lacily around the nephron.

Question 22

Glomerular Filtration

Answer 22

First step of urine formation.

Question 23

Tubular Reabsorption

Answer 23

Only a small fraction of the filtrate will be excreted. Most water and solutes are reclaimed during _______.

Question 24

Tubular Secretion

Answer 24

Transport proteins in the walls of peritubular capillaries actively transport urea and excess ions into the interstitial fluid.

Question 25

Thirst Center

Answer 25

Region of the hypothalamus.

Question 26

Antidiuretic Hormone

Answer 26

Binds to cells of distal tubules and collecting ducts, and causes them to become more permeable to water. As a result, water moves out of the filtrate more freely, peritubular capillaries reabsorb more of it, and less departs in the urine.

Question 27

Aldosterone

Answer 27

Acts on the kidney’s collecting ducts, increasing the activity of sodium-potassium pumps so that more sodium gets reabsorbed.

Question 28

Atrial Natriuretic Peptide

Answer 28

Hormone that makes urine more dilute. Directly inhibits secretion of aldosterone by acting on the adrenal cortex. It also acts indirectly by inhibiting renin release. Increases the glomerular filtration rate.

Question 29

Acid-Base Balance

Answer 29

Metabolic reactions such as protein breakdown and lactate fermentation add H+ to the extracellular fluid. Despite these continual additions, a healthy body can maintain its H+ concentration within a tight range.

Question 30

Buffer System

Answer 30

Involves substances that reversibly bind and release H+ and OH-.

Question 31

Thermal Radiation

Answer 31

Emission of heat from a warm object into the space around it.

Question 32

Conduction

Answer 32

Heat is transferred within an object or among objects that contact one another.

Question 33

Convection

Answer 33

Heat is transferred by the movement of heated air or water away from the source of heat.

Question 34

Evaporation

Answer 34

Heat energy converts a liquid into a gas, a process that cools any remaining liquid.

Question 35

Ectotherms

Answer 35

Fishes, amphibians and reptiles that are “heated from the outside”. Their body temperature fluctuates with the temperature of their environment.

Question 36

Endotherms

Answer 36

Most birds and mammals that are “heated from within”.

Question 37

Hetertherms

Answer 37

Some birds and mammals may maintain a fairly constant core temperature some of the time, but let it shift at other times.

Question 38

Fever

Answer 38

Increase in body temperature that most often occurs as a response to infection.

Question 39

Shivering Response

Answer 39

The hypothalamus commands skeletal muscles to contract ten to twenty times per second. Increases heat production, it has a high energy cost.

Question 40

Nonshivering Heat Production

Answer 40

Thyroid hormone binds to cells of brown adipose tissue. Mitchondria in cells of brown adispose tissue carry out reactions that release energy as heat, rather than storing it in ATP.