Both papers of biology

Question 1

Label the Parts of a microscope.(7)

Answer 1

eye piece lens
objective lens
coarse adjustment knob
fine adjustment knob
lamp
stage
clip

Question 2

Explain adv of electron microscope to light microscope

Answer 2

Higher magnification and better resolution

Question 3

tot magnification = _____________x_____________

Answer 3

eye piece x objective lens

Question 3

Convert mm-um-nm-pm

Answer 3

millimetre= 10-3
micrometre= 10-6
nanometre= 10-9
picometer+10-12

Question 4

Recall the formula to calculate image size.

Answer 4

magnification x real size

Question 5

Recall the formula to calculate magnification

Answer 5

image size divided by real size

Question 6

Recall the formula to calculate actual size

Answer 6

image size divided by magnification

Question 7

Describe the functions of organelles found in Animals.

Answer 7

Nucleus = contains genetic material controls cell activities
cell membrane = holds cell together and controls what goes in and out
cytoplasm = chem reactions happens & contains enzymes to control these reactions
ribosomes = synthesises proteins
mitochondria = site of respiration

Question 8

Describe the functions of organelles found in only plants.

Answer 8

chloroplasts = site of photosynthesis & chlorophyll
cell wall = strengthens and supports cell
vacuole = storage of cell sap, solutions of salt and sugar & maintains internal pressure

Question 9

Compare the contrast in plants and animals.

Answer 9

Plants have Chloroplasts, Vacuole and Cell Wall whereas animal cell doesn’t.

Question 10

How can cells be made visible?

Answer 10

Using stains

Question 11

core Practical : calc magnification label scientific drawings from observation.

Question 12

Ciliated Epithelial cell are adapted. How?

Answer 12

They line the surface of of organs and have cilia on the top of the cell. Their function is to move substances in 1 direction.

Question 13

Egg cell adapted to their function. How?

Answer 13

It contains nutrients in the cytoplasm to feed the embryo,it is rapid and after fertilisation its membrane changes structure to stop sperm

Question 14

Sperm cell adapted. How?

Answer 14

Flahella to swim, lots of mitochondria for energy, acrosome stores digestive to break through membrane of egg cell and is rapid.

Question 15

Describe organelles found in bacterial cells.

Answer 15

Cell membrane = hold cell together ang controls what goes in and out of cell
Ribosomes = synthesis proteins
Flagellum = to move from harmful substances
Plasmid DNA = small loops of extra DNA containing drug resistance
Chromosomal DNA = one long chromosome controls cell activities and rwplication

Question 16

0.0000023 AND 4760000 into standard form

Answer 16

2.3 x 10-6 and 4.67 x 106

Question 17

What are enzymes?

Answer 17

Biological Catalysts

Question 18

Products of starch breakdown are…

Answer 18

Maltose

Question 19

Products of Lipids breakdown are…

Answer 19

Glycerol and fatty acids

Question 20

Products of Protein breakdown are…

Answer 20

Amino acids

Question 21

Describe how enzymes work

Answer 21

They are in chemical reactions. Enzymes have an active site (area that joins to substrate) to catalyse the reaction. Substrates are specific to the active site. This is because the enzyme only works when the enzyme fits into the substrate to create the ‘enzyme substrate complex’ however if it doesn’t fit it cannot catalyse

Question 22

Explain what happens to enzymes in extreme conditions such as Ph and Temperatures.

Answer 22

Enzymes can denatured this is when the shape of the enzyme is altered due to the ph and/or the temperature is to high therefore cannot catalyse the reaction.

Question 23

Recall factors that affect enzyme activity

Answer 23

Substrate concentration
Ph
Temperature

Question 24

Describe how each factor affects enzyme activity

Answer 24

Temperature can change the rate of the reaction as it heats up it will reach the optimised temperature however if it is higher then that the enzyme will denatured this is the same with pH. However with substrate concentration the reaction will be much faster until there’s too much and the active site will all be full and adding more substrates will not make a diffference

Question 25

How to calculate Rate Of Reaction Of Enzyme Activity.

Answer 25

Rate=1000÷time

Question 26

Describe how to carry out a practical to investigate the effect of pH of enzyme activity. Identify the variables (independent, dependent and controls)

Answer 26

1) Put a drop of iodine into every well of a spotting tile.

2) Bunsen burner on top of heat-proof mat and a tripod and gauze over the bunsen burner. Pit beaker of water(35°C) over tripod, keep temp constant.
3) Use syringe to add 3cm3 of amylase solution and 1cm3 of buffer solution with a pH of 5 to a boiling tube. Using test tube holders put it into the beaker of water and wait for 5 minutes.
4)use diff syringe to add 3cm3 of starch solution to the boiling tube.
5)mix contents if the boiling tube and start a stop clock.
6)use continuous sampling to see how long the amylase breaks down the starch to do this use a dropping pipette to take a fresh sample from the tube every 10 seconds and put a dtop onto a well. When the uosine solution is browned orange starch is no longer present.
7) Repeat with different pH levels to see olhpw pH effects the time taken for starch also to be broken
8)Remember to control the variable each time to make it a fair test

Question 27

Describe the process of diffusion

Answer 27

Diffusion is the net movement of particles from an area of higher concentration to a lower concentration.

Question 28

Describe the process of active transport

Answer 28

Active transport is the movement of particles across a membrane against a concentration gradient using energy transferred during respiration.

Question 29

Describe the process of osmosis

Answer 29

Osmosis is the net movement of water molecules across a partially permeable membrane from a region higher water concentration to a region of lower concentration.

Question 30

Describe the movement of water in isotonic, hypertonic and hypertonic solutions

Answer 30

If a cell is placed in a hypertonic solution, water will leave the cell, and the cell will shrink. In an isotonic environment, there is no net water movement, so there is no change in the size of the cell. When a cell is placed in a hypotonic environment, water will enter the cell, and the cell will swell

Question 31

How to calculate % loss or gain in osmosis?

Answer 31

% change = final mass - initial mass ÷ initial mass x100

Question 32

Describe how to investigate osmosis in potatoes. Identify the variables in the practical. Explain what happens when the % change is 0.

Answer 32

1) Prepare sucrose solutions of different concentrations ranging from pure water to a very concentrated sucrose solution.

2) Use a cork borer to cut a potato into the same sized pieces (The pieces need to be about 1cm in diameter and preferably from the same potato.)

3) Divide the cylinders into groups of three and use mass balance to measure the mass of each group.

4) Place one group In each solution.

5) Leave the cylinders in the solution for at least 40 minutes (making sure that they all get the same amount of time).

6)Remove the cylinders and pat dry gently with a paper towel. This removes excess water from the surface of the cylinders, so you get a more accurate measurement of their final masses.

7 ) Weigh each group again and record your results.

8 ) The only thing that you should change in this experiment is the sucrose solution concentration. Everything else (e.g. the volume of solution, the size of the potato cylinders, the type of potatoes used, the amount of drying, etc.) must be kept the same or your results won’t be val’d.

Question 33

What is the function of the ciliated epithelial cell? And what does it so in the air way?

Answer 33

To move substances along in 1 direction. In the air way it moves mucus and particles from the air up the throat so it can be swallowed and doesn’t teach the lungs.

Question 34

Function of egg cell?

Answer 34

Carry female DNA and to nourish the embryo

Question 35

Function of sperm?

Answer 35

Is to transport Male DNA to egg cell.

Question 36

What enzyme breaks down starch to maltose

Answer 36

Amylase

Question 37

Enzymes that breaks down Lipids into glycerol and fatty acids ?

Answer 37

Lipases

Question 38

Enzymes that break down proteins into amino acids

Answer 38

Protease