B3 - Keeping Internal Conditions Constant Flashcards Preview

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Flashcards in B3 - Keeping Internal Conditions Constant Deck (65)
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1

Give three factors that the body has to control.

-Core body temperature.
-Water and ion balance.
-Blood sugar levels.

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2

What are the two main waste products produced in the body?

-Carbon dioxide
-Urea

3

How is carbon dioxide produced in the body?

Through respiration.

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4

Why is it important to remove carbon dioxide from the body?

CO2 dissolves to produce carbonic acid in the blood.

5

What happens if carbon dioxide isn't removed from the body?

Enzymes don't work as efficiently since the pH level would change.

6

What percentage of CO2 is expended from the body?

4%

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7

How is urea produced?

-Excess protein is broken down into amino acids.
-The amino acids are broken down to produce carbohydrates and ammonia.
-The liver converts the ammonia into urea.

8

What happens to the rest of the amino acid molecule when it has gone through the liver?

-It is used for respiration or creating other molecules.

9

Give three ways in which water is lost.

-Breathing
-Sweating
-In urine

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10

Give two ways in which ions are lost.

-Sweating
-In urine

11

What is homeostasis?

The maintenance of constant internal body conditions.

12

Give three functions which the kidney undertakes.

-Filtering out urea from the blood.
-Removing excess water.
-Removing excess ions.

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13

Where is urine stored?

The bladder.

14

What happens to the water passing through the kidneys if the body has very little water?

The water is conserved.

15

What happens to the water passing through the kidneys if the body has a lot of water?

Lots of urine is produced to get rid of the excess.

16

What is left in the blood when passing the kidney tubules?

-Blood cells
-Large molecules
-Proteins

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17

Why can't some molecules diffuse across into the kidney tubules?

They are too big to pass through the membrane of the tubule.

18

How are mineral ions, water and sugars conserved?

They are reabsorbed by the kidneys.

19

How are sugars reabsorbed?

Active transport

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20

How much sugar is conserved by the kidneys?

All of it.

21

What is selective re-absorption?

The control of the amount of water reabsorbed by the kidneys.

22

What make urine yellow?

Urobilins

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23

What are urobilins?

Yellow pigments

24

How are urobilins produced?

The breakdown of haemoglobin in the liver.

25

What are the vein and artery leading to the kidneys called?

The renal vein and artery.

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26

Where is the dirty blood filtered in the kidney?

A glomerulus.

27

What is a glomerulus?

A capillary network.

28

Why is pressure built up in a glomerulus?

To filter most of the liquid.

29

How is high blood pressure built up in a glomerulus?

The vein has a smaller lumen than the artery.

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30

Where are useful substances reabsorbed in the kidney?

A nephron.