Science Ks3 Exam Revision

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Science End Of Year Revision:

Biology

1. Animal and Plant cells
2. Specialized animal and plant cells

3. The 7 life processes:

4. A group of SIMILAR CELLS is called a TISSUE.
A group of DIFFERENT TISSUES forms an ORGAN.
A GROUP OF ORGANS working together from an ORGAN SYSTEM, or even a WHOLE ORGANISM.

CELLSTISSUEORGANORGAN SYSTEM

5. Example of this sequence in plants.

…which, with other tissues make up a leaf (an
ORGAN)…
…which, with other tissues make up a leaf (an
ORGAN)…

…make up palisade
TISSUE…
…make up palisade
TISSUE…
…and leaves and other organs make up a full plan (an
ORGANISM).
…and leaves and other organs make up a full plan (an
ORGANISM).

Palisade
CELLS…
Palisade
CELLS…

6. Definition of DIFFUSION.

Diffusion is the gradual movement of particles from an area of high concentration to an area of low concentration. THE NATURAL TENDENCY FOR STUFF TO SPREAD OUT.

7. Diffusion of smell.
Smell diffused in the air
Smell diffused in the air
Air

Air

Smell
Smell

8. Why are cell membranes kind of clever?

They’re kind of clever because they hold everything inside the cell, BUT, they let stuff in and out as well. Only very small molecules can diffuse through cell membranes though—things like glucose or amino acids.

9. What will and won’t diffuse through cell membranes?

Big molecules such as STARCH and PROTEINS can’t diffuse through cell membranes. Small molecules such as GLUCOS and AMINO ACIDS can diffuse through cell membranes.

10. Root Hair Cell

a) Root hairs take in Minerals and Water from the soil
b) The cells on plant roots grow into long ‘hairs’, which stick out into the soil. This gives the plant a big surface area for ABSORBING water and minerals from the soil.

11. What exactly do enzymes do in the digestive system?

Enzymes act as catalysts to break down big molecules into small ones.

12. 3 different types of enzymes, which foods they act on, and what they produce.

* CARBOHYDRASE
Converts Starch into Simple Sugars.
Carbohydrase is produced in three places: salivary glands (amylase), pancreas, intestines. * PROTEASE
Converts Proteins into Amino Acids.
Protease is produced in three places: the stomach, pancreas, small intestines. * LIPASE
Converts Fats into Fatty Acids and Glycerol.
Lipase is produced in two placed: the pancreas, small intestines.

13. What does bile do? Where is it produced? Where does it enter the system?

Bile is an alkaline substance produced by the liver and stored in the gall bladder. It is secreted into the small intestine, where it emulsifies fats. This is important, because it provides a larger surface area in which the lipases can work.

14. What are the 3 BIG MOLECULES and which kinds of foods are each of them found in? What do they are they broken down into?

STARCH
Found in: Bread, potatoes, muesli.
Broken down into GLUCOSE MOLECULES.

PROTEINS
Found in: Meat, eggs, fish.
Broken down into AMINO ACIDS.

FAT
Found in: Butter, cooking oil, sausages.
Broken down into FATTY ACIDS AND GLYCEROL MOLECULES.

15.

16. Human Circulatory system.

17. Why is it a double circulatory system, and describe the pressure and oxygen content of blood in each bit. What are the big words for saying if the blood has oxygen in it or not?

The heart is actually two pumps. The right side pumps deoxygenated blood to the lungs to collect oxygen. Then the left side pumps this oxygenated blood around the body. It goes from the body to the heart (deoxygenated blood) at the lowest pressure and at high pressure to the lungs. It then (oxygenated blood) goes at low pressure to the heart and at the highest pressure to the rest of the body.

18. The Heart.

19. Blood Vessels.

There are 3 different types of blood vessels.

Large Lumen
Large Lumen
Elastic fibers and smooth muscle.
Elastic fibers and smooth muscle....
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