Unit 5:Lesson 5

Question 1

osmoregulation

Answer 1

the general term for the process by which animals control solute concentrations and balance water gain and loss

Question 2

osmolarity

Answer 2

moles of solute per liter of solution

• isosmotic: two solutions have same
• hyperosmotic: solution with greater osmolarity
• hypoosmotic: solution with less

Question 3

osmoconformers

Answer 3

marine animals that are isosmotic with their environment

Question 4

stenohaline

Answer 4

animals that cannot tolerate extreme changes in external osmolarity

Question 5

euryhaline

Answer 5

the few animals that can survive large fluctuations of osmolarity in their environment

Question 6

Marine Animal Adaptations: osmoconformers

Answer 6

must actively transport specific solutes

Question 7

Marine Animal Adaptations: osmoregulators

Answer 7

• ocean is a strongly dehydrating environment
• may drink large amounts of seawater
• use gills and kidneys to excrete salt

Question 8

Freshwater Osmoregulation

Answer 8

• must be hyperosmotic because animal cells cannot tolerate low salt concentrations of freshwater
• counter by drinking no water, and excreting large amounts of urine
• eat to replenish salt or uptake by gills

Question 9

anhydrobiosis

Answer 9

some invertebrates that live in temporary waters can enter a dormant state when their habitats dry up
-a sugar appears to protect cells by replacing some water

Question 10

Land Animals Osmoregulation

Answer 10

• dehydration is a major regulatory problem
• body coverings prevent water loss
• many are nocturnal, decreasing evaporative water loss
• maintain balance by drinking, eating moist foods, and producing water in cellular respiration

Question 11

Energy use in Osmoregulation

Answer 11

• amount depends on
  
  • difference in osmolarity
  • how easily water and solutes move across the surface
  • work required to pump solutes across a membrane
• energy use limited by body fluids adapted to salinity of a habitat

Question 12

transport epithelia

Answer 12

one or more layers of epithelial cells specialized for moving particular solutes in controlled amounts in specific directions
-usually complex tubular networks

Question 13

ammonia

Answer 13

a form of nitrogen which is removed when proteins and nucleic acids are broken apart or converted
-very toxic as it can interfere with oxidative phosphorylation

Question 14

Ammonia excretion

Answer 14

• can be tolerated only at low concentrations so animals that excrete ammonia need access to lots of water
• excreted by aquatic species as it can diffuse across membrane and dissolve directly into water

Question 15

Urea excretion

Answer 15

• most terrestrial and many marine species don’t have access to enough water to excrete ammonia
• produced by a metabolic cycle in the liver that combines ammonia with carbon dioxide
• low toxicity so it can be transported at high concentrations
• animals have to expend energy to produce

Question 16

Uric Acid

Answer 16

• excreted by insects, snails, reptiles, and birds
• relatively nontoxic
• needs little water to excrete
• synthesis requires considerable ATP

Question 17

Type of Nitrogenous Waste used depends on;

Answer 17

• evolutionary history
• amount of water available
• how wastes can be carried away from eggs
• amount excreted is controlled by energy budget and diet

Question 18

Osmoregulation of Single-celled organisms

Answer 18

-may have contractile vacuoles

Question 19

Osmoregulation of plants

Answer 19

• have cell walls

- turgor pressure counteracts further water uptake

Question 20

Gas Exchange in plants

Answer 20

• structure of plants allows most living cells to have atleast part of surface exposed to surrounding environment
• have stomata

Question 21

Gas Exchange in complex animals

Answer 21

• gas exchange occurs between the environment and bloodstream
• gills and lungs help with this exchange