Chapter 4A

Question 1

What is homeostasis?

Answer 1

This is the organism’s mechanism of maintaining stability with the environment and maintaining a steady internal environment. To maintain the biochemical reactions alterations or changes are made to the temperature, pH, solute concentration, water and pressure.

Question 2

What are you trying to attain with homeostasis/

Answer 2

The goal is to acheive that ideal range where the internal environment is balanced with the external environment.

Question 3

What is the setpoint?

Answer 3

This is the value that the body is trying to maintain it is the ideal condition that the body wants to maintain and if that condition is not met homeostasis will force mechanisms to occur to revert back to that standard.

Question 4

What happens to the external cells?

Answer 4

These cells die fast and are then replaced.

Question 5

What happens to the internal cells?

Answer 5

These cells are protected by homeostasis.

Question 6

What is osmoregulation?

Answer 6

The regulation of the internal osmotic water, salt. or waste.

Question 7

What is circulation?

Answer 7

This is the bulk flow of fluid within the body of water, solute, nutrients, and gases.

Question 8

What is gas exchange?

Answer 8

Gasses being exchanged with the environment.

Question 9

What is pH regulation?

Answer 9

Controlling the H+ concentration of the body’s fluids.

Question 10

Can animal cells maintian turgor pressure?

Answer 10

No - it cannot because plant cells possess cell walls to maintain the pressure but animal cells do not have them.

Question 11

What are osmoconformers?

Answer 11

These are strategies that were used to adjust osmotic strength of cells = the extracellular fluid = to the environment. The osmotic strength of the inside and outside is the same.

Question 12

What are osmoregulators?

Answer 12

These are strategies that were used to adjust the osmotic strength of extracellular fluid = to match the cells and protect the cells from the external environment. The osmotic strength of the inside does not match the outside. Maintain a solute to solvent balance in the organism uptake and lose water or solute.

Question 13

What is isosmotic?

Answer 13

The osmotic pressure is equal to its surroundings. There is no net movement.

Question 14

What is hyperosmotic?

Answer 14

The osmotic pressure is higher than its surroundings. Solutes move from the solution to the surrounding.

Question 15

What is hyposmotic?

Answer 15

The osmotic pressure is lower than its surroundings. Solutes move into the solution from the surrounding

Question 16

What is osmotic pressure?

Answer 16

This is the minimum force that has to be applied to prevent the solvent from flowing through the semipermeable membrane.

Question 17

How is the terrestrial characterized?

Answer 17

As dry

Question 18

How are marine or saltwater characterized?

Answer 18

Hyperosmotic - dry
There is a higher solute concentration outside the organism and lower water concentration outside so water is lost.

Question 19

How is the freshwater characterized?

Answer 19

Hyposmotic
There is a higher solute concentration inside the organism and a lower water volume in the organism so water flows in and the solute flows out.

Question 20

What adapations do seagulls have?

Answer 20

They have salt glands whereby they can uptake saltwater and then release the salt.

Question 21

How do water and air differ in excretion?

Answer 21

Diffusion of the solute can occur in the water but it cannot occur in the air.

Question 22

Is filtration selective?

Answer 22

No filtration is not selective as the ions and small molecules pass into the narrow cells of the tubules despite what they are.

Question 23

Is secretion selective?

Answer 23

Yes secretion is selective because the waste molecules are readded to the filtrate and excreted as waste.

Question 24

Is reabsorption selective?

Answer 24

Yes reabsorption is selective because not everything is necessary some is waste that must be removed but ions some small molecules or water can be reabsorbed by the blood and used in the body.

Question 25

What is the only way for organisms to alleviate waste?

Answer 25

Through filtrate where only excretion can occur.

Question 26

What are the challenges of osmoregulation?

Answer 26

The organisms that are adapted to freshwater or marine life have those specific adaptations of losing or gaining water therefore it is difficult when the organisms migrate.