Biology

Question 1

What are the characteristics of living organisms?

Answer 1

They move, reproduce, sense the surroundings, grow, respire, excrete waste, and need nutrition.

Question 2

What is a eukaryote, and what is an example?

Answer 2

Any organism with a membrane bound nucleus.

Question 3

What is a prokaryote, and what is an example?

Answer 3

Single celled organism without a membrane bound nucleus.

Question 4

Describe the effect of temperature on an enzyme - controlled reaction.

Answer 4

• As kinetic energy of particles increases, enzymes and substrate molecules collide more often, so the rate of reaction increases. -The optimum temperature is when particles are colliding as quickly as possible. - Then the active site changes shape, and the rate of reaction slows. Enzymes ‘denature’.

Question 5

Define: pulmonary, hepatic and renal.

Answer 5

Lungs, liver, and kidneys.

Question 6

What is an enzyme, and what does it do?

Answer 6

Enzymes are protein catalysts. They speed up useful chemical reactions in organisms (metabolic reactions).

Question 7

What makes a plant and what is an example?

Answer 7

Plants are multicellular, cells contains chloroplasts - can photosynthesise, have cellulose cell walls, and store carbohydrates as starch. Tomato plant.

Question 8

What makes an animal, and what is an example?

Answer 8

Animals are multicellular, cells do not have chloroplasts - cannot photosynthesise, no cell walls, store carbohydrates as glycogen.

Question 9

What makes a fungi and what is an example?

Answer 9

They can have mycelium made of branching filaments called hyphae. Some are single celled, cannot photosynthesise - use saprotrophic nutrition where they dissolve food with enzymes then absorb it, cell walls made of chitin, store carbohydrates as glycogen. Yeast

Question 10

What makes a protoctist and what is an example?

Answer 10

Protoctists are single celled, some have chloroplasts. Plasmodium causes malaria.

Question 11

What is a bacteria and what is an example?

Answer 11

Bacteria are single celled, have a cell wall, cell membrane, cytoplasm and plasmids, no nucleus but do have DNA. Some can photosynthesise. Pneumococcus causes pneumonia

Question 12

What makes a virus and what is an example?

Answer 12

Parasites that depend on living organisms to reproduce. Have a protein coat around genetic material (DNA or RNA). Influenza virus causes flu.

Question 13

What organisms are pathogens and what diseases do they cause?

Answer 13

Protoctists can cause malaria, bacteria can cause pneumonia and viruses can cause rabies.

Question 14

Describe some organelles in a typical plant cell.

Answer 14

Chloroplasts carry out photosynthesis contains chlorophyll. Cell wall made of cellulose is made of cellulose. Large vacuole contains cell sap which supports the cell.

Question 15

Describe some organelles in a typical animal cell.

Answer 15

The nucleus contains genetic information, controls cell’s activities. Cell membrane surrounds cell controls what goes in and out. Cytoplasm is where chemical reactions take place. Ribosomes are where proteins are made. Mitochondria is where aerobic respiration takes place.

Question 16

What are tissues and organs?

Answer 16

Tissues are similar cells that work together to carry out a particular function (eg muscle tissue). Organs are groups of tissues, which make up organ systems. Digestive system.

Question 17

What does an enzyme do in a reaction?

Answer 17

It breaks up or joins together chemicals called substrates. The substrate enters the active site of a specific enzyme and gets reacted.

Question 18

How does pH affect enzymes?

Answer 18

It changes the rate of reaction, the pH affects the bonds holding the enzyme together. The enzyme denatures the shape of active site the further it is from the optimum pH.

Question 19

Describe an investigation for how temperature affects enzymes.

Answer 19

Put drops of iodine into spotting tile, and add amalyse ans dtarrch solution???

Question 20

What is diffusion?

Answer 20

The net movement of particles from an area oh higher concentration to an area of lower concentration.

Question 21

What is osmosis?

Answer 21

The net movement of water molecules across a partially permeable membrane from an area of higher water concentration to an area of lower water concentration.

Question 22

How could you investigate diffusion in a non-living system?

Answer 22

Phenolphthalein and sodium hydroxide agar jelly cubes put into a beaker with HCl. Pink phenolphthalein will turn colorless as acid diffuses into it. Can investigate the rate of diffusion by using sized cubes - largest surface area to boule ratio will diffuse fastest.

Question 23

How could you investigate osmosis in a living system?

Answer 23

Identical potato cylinders into different beakers with different concentrations of sugar solution. Leave. If water is drawn in by osmosis they will grow, if water drawn out they will have shrunk.

Question 24

How could you investigate osmosis in a non-living system?

Answer 24

Fix Visking tube to the end of a thistle funnel and fill with sugar solution. Put into a beaker of water, and measure where the sugar syrup comes up to in the glass tube . Leave. Measure again. Water should have been drawn up through the tube by osmosis.

Question 25

What is active transport? Where is it used?

Answer 25

The movement of particles against a concentration gradient (from an area of lower concentration to higher concentration), using the energy released by respiration. E.g. Plants take nutrients from soil.

Question 26

What factors affect the movement of substances?

Answer 26

• Surface area to volume ratio: movement will happen faster with a large surface area compared to the volume. - Temperature: particles move faster, substances move more in and out of cells faster. - Distance : - Concentration gradient : particles will move faster the larger it is. This doesn’t affect active transport.

Question 27

What is the chemical structures of carbohydrates?

Answer 27

C, H and O. Starch and glycogen are complex carbohydrates made up of smaller units - maltose or glucose.

Question 28

What is the chemical structures of lipids?

Answer 28

C, H, and O made up of fatty acids and glycerol.

Question 29

What is the chemical structures of proteins?

Answer 29

C, H, O and N. Made up of long chains of amino acids

Question 30

What are the tests for different biological molecules?

Answer 30

• To test for glucose, use Benedicts agent in a water bath. It will turn for blue to yellow or brick-red depending on the concentration of glucose.. - For starch, iodine turns from brown to blue black. - For proteins Biurettes solution goes from blue to purple

Question 31

What are the functions of the different nutrients?

Answer 31

• Carbohydrates : energy. - Lipids : Energy and insulation. - Proteins : Growth and repair. - Vitamin A (found in liver): Vision and skin. - Vitamin C : Prevents scurvy. -Vitamin D (found in eggs) : calcium absorption. - Iron : Haemoglobin. - Water: Replaces water lost in urinating, sweating. Dietary fibre (found in fruit) : helps movement through gut.

Question 32

How is food moved through gut?

Answer 32

Peristalsis uses circular muscle contractions to push and squeeze boluses through the gut.

Question 33

What does bile do?

Answer 33

Bile is produced in the liver and stored in the gall bladder, then released into the small intestine. It neutralises hydrochloric acid so enzymes can work more effectively, and it emulsifies fats - breaks fat into tiny droplets, with large surface area for enzymes, to make digestion faster.

Question 34

What do the different digestive enzymes do?

Answer 34

Digestive enzymes break large insoluble molecules into soluble absorbable ones. - Amalyse coverts starch to maltose. -Maltase converts maltose to glucose. - Protease convert proteins into amino acids. - Lipase converts lipids into glycerol and fatty acids.

Question 35

From the mouth to pancreas describe the journey of food.

Answer 35

• Amalyse in saliva starts to break down food. - Teeth break down food. - Oesphagus connects mouth to the stomach. - The stomach pummels food, and produces protease peptin and HCl. HCl kills bacteria and provides optimum pH for peptin. - Pancreas produces protease, amalyse and lipase which are released into the small intestine.

Question 36

Describe the journey of food from the small intestine to the anus.

Answer 36

• The small intestine produces protease, lipase ad amalyse to complete digestion. It absorbs the nutrients. - The first part of the small intestine is the duodenum and the second part the ileum. - Excess water is absorbed in the large intestine. - Rectum stores food before egestion.

Question 37

How is the small intestine and villi adapted for absorption?

Answer 37

It is long, giving time food food to break down. Millions and millions of villi maximise surface area, with micro-villi. Villi have a single permeable membrane (short distance for diffusion), and a constant blood flow.

Question 38

What is the photosynthesis symbol equation?

Answer 38

6CO2 +6H2O => C6H12O6 +602