Bio Final

Question 1

What is osmoregulation?

Answer 1

The exchange of water and ions between the body and environment to maintain homeostasis

Question 2

What are the three types of nitrogenous wastes?

Answer 2

Nitrogenous wastes are produced through the metabolism of proteins and nucleic acids and must be excreted because of their toxicity 1. Ammonia 2. Urea 3. Uric acid

Question 3

What types of animals produce ammonia?

Answer 3

invertebrates, most fish, and larval amphibians

Question 4

What types of animals produce urea?

Answer 4

present in mammals, some terrestrial animals, invertebrates, and adult amphibians

Question 5

What types of animals produce uric acid?

Answer 5

Reptiles and birds

Question 6

What is the benefit and disadvantage of ammonia?

Answer 6

Inexpensive to make but very toxic

Question 7

What is the benefit and disadvantage of urea?

Answer 7

Less toxic than ammonia but more expensive to make

Question 8

What is the benefit and disadvantage of uric acid?

Answer 8

low solubility; forms precipitate but very expensive to make

Question 9

What are the functions of animal excretory systems in general?

Answer 9

Filtration, absorption, excretion, secretion

Question 10

How do animals without circulatory systems perform these functions?

Answer 10

These animals perform excretory functions through diffusion across their body wall. Platyhelmetheses also has a protonephridial system that helps them get rid of excess water (osmoregulation)

Question 11

How does the protonephridial system work?

Answer 11

composed of 2 cells that interlock and surround a tuft of cilia (“flame cell”). This is the “closed inner end” through which fluid is drawn. The beating cilia draws fluid between the finger-like extensions. From here fluids pass into tubules lined with microvilli for resorption of salts and other needed substances. From the tubules, waste fluid is expelled via the nephridiopores

Question 12

How does the metanephridial system work?

Answer 12

ciliated tubules pump surplus ions, metabolic wastes, toxins, etc… out of the organism by directing them down funnel-shaped bodies called nephrostomes. As the metabolic wastes move through the body, the cilia absorb the cavity fluid while specialized tubule cells absorb any useful nutrients that remain in the waste. The primary urine produced by filtration of circulating fluid (blood) is converted into secondary urine through selective reabsorption by the cells lining the metanephridium. Once the wastes that are filtered out have been fully processed through the body cavity, what remains is passed out of the earthworm’s body through a structure called the nephridiopore.

Question 13

Why are annelids excretory system considered more advanced?

Answer 13

Nutrients and urine are filtered and absorbed twice before being excreted.

Question 14

What types of excretory systems are found in arthropods?

Answer 14

Malpighian Tubules

Question 15

Describe the malpighian tubule system in insects.

Answer 15

Malpighian Tubules are thin tubes that branch from the junction of the mid and hindgut. They project into the hemocoel and absorb hemolymph. The Malpighian tubules are lined with transport epithelium, and energy is used to move most substances into the Malpighian Tubules. Substances that the organisms needs to keep are resorbed by the rectal glands in the hindgut. Arthropods with this type of excretory system generally produce a uric acid paste that is excreted with feces.

Question 16

How does the exoskeleton help insects in osmoregulation?

Answer 16

The exoskeleton prevents water loss and allows arthropods to live on land.

Question 17

How do sharks and fish differ in their osmoregulation?

Answer 17

In fish, salts are diffused across gill surfaces in the epithelium. Whereas in sharks excess salts are excreted via the rectal gland

Question 18

How is osmoregulation different in freshwater fishes than in marine fishes?

Answer 18

Freshwater fishes tend to gain water and lose salts to the environment, so they take up salts through food and salt absorbing cells in the gill epithelium. Marine fishes tend to lose water and gain salts from the environment, so they drink salt water to gain more water and secrete excess salts through cells of the gill epithelium.

Question 19

Why do birds and reptiles have salt glands, but mammals don’t?

Answer 19

some marine birds and reptiles do not have access to enough freshwater to enable them to get rid of enough excess salts. These animals have special salt glands that remove salt from the blood and excrete salts as salty droplets that drip from their nasal passages. Mammals do not have salt glands because they don’t take in as much salt.

Question 20

What are some adaptations seen in desert rodents that enable them to live without ever drinking water?

Answer 20

They have a long loop of Henle which allows them to conserve water, produce dry feces, are nocturnal and burrow, have a low protein diet, and have long respiratory passages

Question 21

What is the function of the vertebrate kidney?

Answer 21

They remove waste products from the body, maintain balanced electrolyte levels, and regulate blood pressure.

Question 22

What is the renal cortex?

Answer 22

The renal cortex is the outside portion of the kidney that houses the glomerulus and convoluted tubules of the nephrons

Question 23

What is the renal medulla?

Answer 23

The renal medulla is the middle portion of the kidney that houses the loops of Henle. The juxtamedullary nephrons have especially long loops of Henle that extend deep into the medulla

Question 24

What is the renal pelvis?

Answer 24

the renal pelvis is where the collecting tubules of nephrons dump their filtrate (urine). From the renal pelvis, urine passes into the ureter and then to the bladder.

Question 25

What are the three main processes in urine formation? glomerular filtration, reabsorption, and secretion

Answer 25

glomerular filtration, reabsorption, and secretion

Question 26

How is urine production regulated by the nervous and endocrine systems?

Answer 26

The nervous system and endocrine system monitor the osmolarity of blood and regulate hormones responsible for increasing or decreasing the water permeability of the kidney

Question 27

Where is ADH stored, secreted, and produced?

Answer 27

ADH is produced in the hypothalamus and stored and secreted by the posterior pituitary gland

Question 28

How does ADH control the osmolarity of urine?

Answer 28

osmoreceptors in the brain monitor the osmolarity of blood. When blood osmolarity increases the hypothalamus stimulates the pituitary gland to increase secretion of ADH (antidiuretic hormone) ADH makes the collecting ducts in the kidney more water permeable so that more water is conserved, and a concentrated urine is produced. The hypothalamus also triggers a feeling of thirst. When osmolarity decreases, ADH secretion decreases. If large quantities of water decrease osmolarity to below the normal set point, less ADH is released which has the effect of decreasing water permeability of the collecting ducts so that less water is reabsorbed, and more dilute urine is produced.

Question 29

What is thermoregulation?

Answer 29

the ability to maintain a constant internal body temperature.

Question 30

What is an endotherm?

Answer 30

“internal heat source” endotherm is able to create enough metabolic heat that they can maintain a constant body temperature. Example is people

Question 31

What is an ectotherm?

Answer 31

“external heat source” does not generate enough heat to affect body temperature. Ectotherms are dependent on the environment for heat. Think snake basking in the sun

Question 32

What is a regional heterotherm?

Answer 32

An organism that is able to maintain different temperature “zones” in different regions of the body.

Question 33

Why is body temperature important?

Answer 33

Enzymes in the body function at a specific temperature in every organism, keeping them at the optimal temperature allows the body to carry out its needed everyday processes.

Question 34

What are the four categories of adaptations used in thermoregulation?

Answer 34

1. Adjusting the amount of heat exchange between the environment and the animal, 2. Evaporative cooling, 3. Behavioral responses, 4. Changing the amount of metabolic heat production

Question 35

How does countercurrent exchange in the two limbs of the Loop of Henle assist in urine formation?

Answer 35

The ascending limb (not permeable to water) leads to a higher concentration of sodium on the outside of the tubule. The descending limb is permeable to water so water comes out towards the higher sodium concentration making the concentration of the descending limb increase. Because of this, there is a constant shuttling of salts creating a higher concentration, therefore, bringing out more water throughout the loop of Henle. This process makes the medulla saltier which brings out more water and a higher concentration of salts for Urine to be excreted with.

Question 36

What are the characteristics of life?

Answer 36

1. Movement 2. Response to stimuli 3. Maintains homeostasis 4. Comprised of one or more cell 5. Has growth and metabolism 6. Reproduces 7. Heredity (passes on genetic information)

Question 37

Maintains a constant internal environment

Answer 37

Homeostasis

Question 38

When changes in the environment/a situation favors a characteristic in an organism putting more of those advantageous genes in the gene pool of the next generation

Answer 38

Natural selection

Question 39

a change in the allele frequency in the gene pool of a population

Answer 39

Evolution

Question 40

some organisms leave more offspring than others

Answer 40

Reproductive fitness