B1

Question 1

How do you work out the total magnification on a microscope?

Answer 1

Eyepiece lens magnification X objective lens magnification

Question 2

How do you work out the image size?

Answer 2

Magnification X real size

Question 3

What is the word equation

for aerobic respiration?

Answer 3

Glucose + oxygen -> carbon dioxide +water

Question 4

List four features that animal and plant cells have in common

Answer 4

Cell membrane, cytoplasm, mitochondria and nucleas

Question 5

Give two sub-cellular structures that are present in prokaryotic cells but not eukaryotic cells

Answer 5

Plasmids and chromosomal DNA

Question 6

How have electron microscopes been able to increase our understanding of sub-cellular structures?

Answer 6

They have let us see much smaller things in more detail (like the internal structure of mitochondria)

Question 7

Why is it important to take a thin slice of a sample before viewing it under a light microscope?

Answer 7

So light can be let through it allowing you to see it clearly

Question 8

Give the initials of the four bases present in DNA

Answer 8

G,C,A,T

Question 9

Describe the structure of a nucleotide

Answer 9

The base is attached to the sugar which is attached to the phosphate. The base is the only part of the molecule that varies.

Question 10

What is a gene?

Answer 10

A section of DNA that codes for a particular protein

Question 11

What is the triplet code?

Answer 11

The three bases (in the gene) in a particular sequence that code for an amino acid

Question 12

What is the process of making mRNA from DNA called?

Answer 12

Transcription

Question 13

In what part of a cell are amino acids joined together to form a protein?

Answer 13

Cytoplasm

Question 14

What does it mean when an enzyme has been denatured?

Answer 14

The bonds holding the enzyme together have been broken due to high temperatures

Question 15

Give two things that you could measure when investigating the rate if an enzyme-controlled reaction

Answer 15

Measure how fast a product appears (how much oxygen produced in a certain time) or how fast a substrate disappears (time taken for starch to break down to maltose so iodine remains browny-orange instead of turning blue-black)

Question 16

Give two variables that need controlling when investigating the effect of pH on an enzyme-controlled reaction

Answer 16

Temperature, potato (starch) used

Question 17

What is respiration?

Answer 17

The process of transferring energy from the breakdown of glucose

Question 18

Is respiration an exothermic or endothermic reaction?

Answer 18

Exothermic (transfers energy into the environment in the form of heat)

Question 19

Name the type of respiration that requires oxygen

Answer 19

Aerobic

Question 20

Give an example of when lactic acid would be produced as a product of respiration

Answer 20

During vigorous exercise

Question 21

Which form of respiration transfers more energy per glucose molecule?

Answer 21

Aerobic

Question 22

Briefly describe an experiment to show that carbon dioxide is a product of respiration

Answer 22

Two test tubes;
Test tube A germinating beans- respiring
Test tube B boiled beans - dead so not respiring
Beans above hydrogen-carbonate indicator on gauze
Respiring beans produce CO2 so indicator turns yellow

Question 23

What type of polymer do you get when you join together simple sugars?

Answer 23

Carbohydrates

Question 24

Name the basic units lipids are made from

Answer 24

Glycerol and 3 fatty acids

Question 25

What can you conclude if a test sample turns a blue-black colour when iodine is added?

Answer 25

Starch is present

Question 26

How would you test for lipids in a sample solution?

Answer 26

Shake substance with ethanol until dissolved (for about a minute), then pour solution into water. If lipids are present, milky emulsion is shown. More lipids = more noticeable milky colour

Question 27

In what part of a cell does photosynthesis take place?

Answer 27

Inside chloroplasts which contain chlorophyll that absorb light

Question 28

Give three factors that can limit the rate of photosynthesis

Answer 28

Light intensity, concentration of CO2 and temperature