Y10 Spring Term Biology Roundup

Question 1

What is the digestive system?

Answer 1

An organ system in which organs work together to digest and absorb food

Question 2

Name the organs in the digestive system (chronological order)

Answer 2

Mouth, Oesophagus, Liver, Stomach, Gallbladder, Pancreas, Small intestine, Large intestine and Anus

Question 3

How do you test for:

1) Sugar (glucose)
2) Starch
3) Biuret

Answer 3

1) Benedict’s test - orange to brick red precipitate
2) Iodine test - turns black
3) Biuret reagent - mauve/purple solution

Question 4

What are cells?

Answer 4

The basic building blocks of all living organisms

Question 5

What are tissues?

Answer 5

A group of cells with a similar structure and function

Question 6

What are organs?

Answer 6

Aggregations (working together) of tissues performing a specific function

Question 7

What are organ systems?

Answer 7

Organs working together to form organ systems which work together to form an organism

Question 8

What is the job of enzymes?

Answer 8

Enzymes catalyses (increase the rate of) specific reactions in living organisms

Question 9

How do enzymes catalyse specific reactions?

Answer 9

Due to the shape of their active site

Question 10

What is “the lock and key” theory?

Answer 10

A simplified model to explain enzymes in action

Question 11

What factors affect the activity of enzymes?

Answer 11

Temperature and pH

Question 12

What does every active enzyme have?

Answer 12

1) An optimum temperature
2) An optimum pH

Question 13

What is meant by the term “a denatured enzyme”?

Answer 13

An enzyme that has changed shape so the substrate no longer fits the active site

Question 14

What can cause an enzyme to become denatured?

Answer 14

• Temperature is too high
• pH is too high/low

Question 15

What’s the job of digestive enzymes?

Answer 15

To speed up the conversation of large, insoluble molecules (food) into small, soluble molecules that can be absorbed into the bloodstream

Question 16

Describe the function of amylase (carbohydrases)

Answer 16

• Made in the salivary glands, pancreas + small intestine
• Break down carbohydrates into simple sugar (eg. starch to glucose)

Question 17

Describe the function of proteases?

Answer 17

• Made in the stomach + pancreas
• Break down proteins to amino acids

Question 18

Describe the function of lipases?

Answer 18

• Made in the pancreas but works in the small intestine
• Break down lipids (fats) into glycerol and fatty acids

Question 19

Describe the function of bile

Answer 19

• Made in the liver but stored in the gallbladder
• Emulsifies lipids to increase surface area to increase lipid breakdown by lipase. Changes pH to neutral for lipase to work

Question 20

What are the epidermal tissues?

Answer 20

• Waxy cuticle (top layer of the leaf)
• Guard cells
• Stomata

Question 21

Describe the job of the waxy cuticle?

Answer 21

Reduce water loss from the leaf

Question 22

Describe the job of the guard cells/stomata?

Answer 22

Guard cells open/close the stomata to control water loss and allow gas exchange

Question 23

Describe the job of the palisade mesophyll (palisade cells)?

Answer 23

Cells near the top surface of the leaf that are packed with chloroplasts that contain chlorophyll. Both adaptations maximise photosynthesis

Question 24

Describe the job of the spongy mesophyll

Answer 24

• Air spaces in the leaf between the cells
• Increased surface area for gas exchange so that carbon dioxide can diffuse into photosynthesising cells

Question 25

Describe the job of the xylem

Answer 25

- Hollow tubes strengthened by lignin adapted for the transportation of water in the transpiration system - Allows transport of water and mineral ions from the roots to the stem and leaves

Question 26

Describe the job of the phloem

Answer 26

- Cell sap moves from one phloem cell to the next through pores in the end walls - Transports dissolved sugars from the leaves to the rest of the plant for immediate use/storage (translocation)

Question 27

Describe the job of the meristem tissue

Answer 27

- New cells (roots and shoot tips) are made here including root hair cells - Root hair cells have an increased surface area for the uptake of water by osmosis and mineral ions by active transport

Question 28

State the cause, effect and treatment for faulty heart valves

Answer 28

- Cause: Valves don’t open/close properly - Effect: Blood can leak/flow in the wrong direction - Treatment: Biological valve transplant or a mechanical valve can be installed

Question 29

State the cause, effect and treatment for coronary heart disease

Answer 29

- Cause: A build up of fatty substances in the coronary arteries (atherosclerosis) - Effect: Oxygenated blood cannot get to the cardiac muscle - Treatment: Stents —> inserted into the blocked artery to open it up. Statins —> lower harmful cholesterol