Q + As

Question 1

In which part of the cell is energy released during respiration?

Answer 1

Mitochondrion (ia)

Question 2

Why is it possible to see a bacterial colony but not a single bacterium?

Answer 2

1 bacterium is tiny, many massed together in a colony can be seen

Question 3

Why do muscle cells need a lot of mitochondria?

Answer 3

Because they release energy which muscles need for movement

Question 4

What determines the net movement of particles across a cell membrane?

Answer 4

The concentration on either side of the membrane

Question 5

What does glandular tissue produce?

Answer 5

Enzymes or hormones

Question 6

Where is soluble food absorbed?

Answer 6

Small intestine

Question 7

Where does the energy for photosynthesis come from?

Answer 7

Sunlight but artificial light may be used in experiments

Question 8

Why do enzyme reactions slow down?

Answer 8

When the temperature falls, the enzymes work slower

Question 9

What is meant by the term ‘dependent variable’?

Answer 9

The variable that is being measured

Question 10

What are 3 substances used for storage in plants?

Answer 10

Starch, Fats and Oils

Question 11

What factors must be controlled in a greenhouse to improve plant growth?

Answer 11

Light, Temperature, Carbon Dioxide

Question 12

Why are there so few animals living in very cold regions such as the Arctic?

Answer 12

Few plants grow there and those that do are very small so there isn’t much food for animals to survive

Question 13

What is a quadrat?

Answer 13

A square frame that can be divided into a grid

Question 14

How can you make sure an investigation is valid?

Answer 14

Control all variables apart from the independent

Question 15

What are proteins made of?

Answer 15

Long chains of amino acids

Question 16

What is meant by the term ‘denatured’?

Answer 16

When the enzyme/protein changes shape and stops working

Question 17

Which enzyme digests starch?

Answer 17

Amylase

Question 18

Where is bile produced?

Answer 18

Liver

Question 19

Which enzyme converts glucose into fructose?

Answer 19

Isomerase

Question 20

How do enzymes get into rivers?

Answer 20

Water from dishwashers/washing machines passes into the sewage system and eventually might get to the rivers

Question 21

Where does aerobic respiration take place?

Answer 21

Mitochondria

Question 22

Which sugar is needed by the muscles for aerobic respiration?

Answer 22

Glucose

Question 23

Which type of cell division produces 2 identical cells from the original cell?

Answer 23

Mitosis

Question 24

What type of cells are produced by meiosis?

Answer 24

Gametes

Question 25

Explain how 4 gametes are formed from 1 cell

Answer 25

2 sets of cell division. A body cell divides into 2 and then each divides again.

Question 26

Where are stem cells found in adult humans?

Answer 26

Bone marrow

Question 27

Which scientist worked out how characteristics are inherited?

Answer 27

Gregor Mendel

Question 28

What does a gene code for?

Answer 28

The order of amino acids in a protein

Question 29

Which sex chromosomes are found in human males?

Answer 29

X and Y (XY)

Question 30

What is meant by the term 'phenotype'?

Answer 30

Description of physical characteristics

Question 31

Name a genetic disorder which is controlled by a dominant allele

Answer 31

Polydactyly

Question 32

What are the chances of a child having cystic fibrosis if one parent has the disorder and the other parent is heterozygous?

Answer 32

50% As one parent (cc) has to pass on the allele, the other parent (Cc) has a 50% chance of passing it on. The child is either Cc or cc

Question 33

What is embryo screening?

Answer 33

Test are carried out on the embryo to diagnose possible disorders

Question 34

Name a hard part of an animal which will NOT decay easily

Answer 34

Bones, Teeth, Shells, Claws

Question 35

Why are some fossils destroyed over time?

Answer 35

Because of geological activity which breaks them up/wears them away

Question 36

How can a new predator cause extinction of a species?

Answer 36

It eats all the animals of that species

Question 37

Suggest another factor which could have caused dinosaurs to die out?

Answer 37

A new disease being introduced into the population. It's unlikely to be a new predator because dinosaurs were at the top of the food chain.

Question 38

How do populations become isolated?

Answer 38

Islands break away from the mainland, new rivers form, mountain ranges or craters separate the populations

Question 39

What is meant by genetic variation?

Answer 39

The wide range of alleles that control the characteristics in a population