Osmoregulation and Waste Disposal

Question 1

Osmoregulation

Answer 1

Management of the bodies water content and solute composition

Question 2

How do animals regulate chemical composition of their body fluids

Answer 2

Balancing the uptake and loss of water and fluids (but must also manage metabolic waste products)

Question 3

Osmoregulators

Answer 3

Expend energy to control their internal osmolarity

Question 4

Osmoconformers

Answer 4

Isosmotic with their surroundings

Question 5

What kind of osmoregulation are most marine invertebrates

Answer 5

Osmoconformers

Question 6

What is osmolarity

Answer 6

The concentration of all the particles dissolved in body fluid

Question 7

What kind of osmoregulation are most marine vertebrates

Answer 7

Osmoregulators

Question 8

Marine fish osmoregulation

Answer 8

FIsh constantly loose water through their skin and gills

To balance this, these fish obtain water and food by drinking large amounts of seawater and they excrete. ions by active transport out of the gills.

Question 9

Freshwater animal issue with osmoregulation

Answer 9

Constantly gain water by osmosis and lose salts by diffusion

Question 10

How do freshwater protists balance excess water

Answer 10

Have contractile vacuoles that pump out excess water

Question 11

How do freshwater fish maintain balance

Answer 11

• Excreting large amounts of very dilute urine
• Regaining lost salts in food
• Active uptake of salts from their surroundings

Question 12

What does the amount/kind of nitrogenous waste depend on

Answer 12

• Energy budget
• How much and what kind of food animal eats
• Evolutionary history and habitat (especially water availability)

Question 13

Animals that excrete nitrogenous waste as ammonia

Answer 13

• Need access to lots of water as ammonia is very soluble but can only be tolerated at very low concentrations

Question 14

Aquatic species nitrogenous waste form

Answer 14

Often ammonia. Most of ammonia is lost as ammonium ions (NH4+) at the gill epithelium

Question 15

What can freshwater fish do with ammonia ions

Answer 15

Exchange NH4+ for Na+ from the environment

Question 16

Issues with excreting ammonia

Answer 16

Because ammonia is so toxic, it can only be transported and excreted in large volumes of very dilute solutions - A big issue for organisms that are water limited

Question 17

How do water limited organisms dispose of nitrogenous waste without ammonia

Answer 17

Urea is synthesised in the liver by combining ammonia with carbon dioxide and excreted by the kidneys

Question 18

Issues with urea as disposal

Answer 18

Energetically expensive

Question 19

What animals use uric acid

Answer 19

Insects, birds, and reptiles

Question 20

How is Uric acid different from ammonia and urea

Answer 20

Largely insoluble in water can can be excreted as a semisolid paste with small water loss

Question 21

Pro and con of uric acid

Answer 21

Saves even more water than urea, however is even more energetically expensive to produce

Question 22

How do shelled eggs of birds deal with nitrogenous wastes

Answer 22

Shelled eggs are impermeable, therefore soluble nitrogenous wastes trapped within could accumulate to dangerous levels. Therefore in these animals, Uric acid precipitatess out of solution and is stored within the egg as a harmless solid

Question 23

What does osmotic regulation and metabolic waste disposal depend on in most animals

Answer 23

Ability of a layer, or layers, of transport epithelium to move specific solutes in controlled amounts in particular directions

Question 24

Countercurrent exchange in fish

Answer 24

As blood moves anteriorly in gill capillary, it becomes more and more oxygen saturated. But, simultaneously encounters water with even higher oxygen concentrations because it is just beginning its passge over the gills.

Question 25

anhydrobiosis in aquatic vertebrates

Answer 25

Dehydrate, losing almost all their body water, and survive in a dormant state

Question 26

Trimethylamine oxide

Answer 26

A salt that sharks store making the sharks more salty than their environment

Question 27

Purpose of Trimethylamine oxide

Answer 27

Salt ions dont constantly diffuse from the ocean into the shark

Question 28

Why shouldn’t you shave a camel

Answer 28

Results in greater daily water loss

Question 29

Beetle in desert adaptation to water conservation

Answer 29

Stand on a hillside and and water that collects on a beetle overnight will roll down into the beetles mouth so it can drink

Question 30

How do we gain water and salts

Answer 30

Food, liquid, metabolism

Question 31

How do we lose water and salt

Answer 31

Urine, Feces, Evaporation

Question 32

Chemical reason as to why we produce nitrogenous waste

Answer 32

Proteins –> Amino acids
Nucleic acids –> Nitrogenous bases

Amino acid + Nitrogenous base = Amino group

Question 33

Hyperosmotic

Answer 33

The amount of solutes in the fish is greater than that of the water

Question 34

Hyposmotic

Answer 34

amount of solutes in fish is less than that of surroundings