General Past Paper Corrections

Question 1

Give one function of the small intestine.

Answer 1

Produces protease, amylase and lipase to complete digestion

It also absorbs nutrients out of the alimentary canal and into the body

Question 2

What is ingestion?

Answer 2

Taking food in mouth and swallowing

Question 3

What is digestion?

Answer 3

Breaking down into smaller pieces and molecules

Question 4

What is absorption?

Answer 4

Taking small molecules from the gut into the blood

Question 5

What is assimilation?

Answer 5

Molecules gained from food used to build new ones - cells and tissues

Question 6

What is egestion?

Answer 6

Passing indigestion food through the anus

Question 7

What is one function of the pancreas?

Answer 7

Secretes amylase

Question 8

Give an example of diffusion in the lung of the mammal

Answer 8

Oxygen moves from the alveoli to the blood

Question 9

Give an example of osmosis in the kidney of a mammal

Answer 9

Glucose which moves from the nephron to the blood

Question 10

Give an example of active transport in a flowering plant

Answer 10

Uptake of mineral salt which moves from the salt to the cytoplasm in a root hair cell

Question 11

What is the function of lipids?

Answer 11

To provide energy and store it, and insulate

Question 12

What is the vitamin C deficiency problem?

Answer 12

Scurvy

Question 13

What is vitamin D deficiency problem?

Answer 13

Rickets

Question 14

What is the deficiency problem of calcium?

Answer 14

Rickets

Question 15

What are the 2 products of lipid digestion?

Answer 15

Glycerol and fatty acids

Question 16

What contains RNA strands?

Answer 16

Virus’s

Question 17

What is the definition of nutrition?

Answer 17

Taking in food required to live

Question 18

What is the definition of growth and development?

Answer 18

Making new cells

Question 19

Where does peristalsis occur?

Answer 19

The whole alimentary canal

Question 20

Name one carbohydrate found in plants that contains carbon

Answer 20

Starch

Question 21

Why are nitrates needed to help plants grow?

Answer 21

To make amino acids and proteins

turns yellow if there’s not enough

Question 22

Why are phosphates needed for plants?

Answer 22

To make DNA and cell membranes for respiration

Question 23

Why is potassium needed in plants?

Answer 23

To help enzymes for respiration and photosynthesis

Question 24

What are the effects of lack of phosphates in a plant?

Answer 24

Poor root growth and purple leaves

Question 25

What are the effects of not enough potassium in a plant?

Answer 25

Poor flower and fruit growth

Question 26

Why is magnesium needed in a plant?

Answer 26

Only needed in small amounts to make chlorophyll

Question 27

How do mineral ions enter plants?

Answer 27

Through root hair cells by active transport, and transport through the xylem

Question 28

What are the effects of fertilisers washing into rivers? (7)

Answer 28

Leaching occurs due to nitrates spilling Algal blooms Light can't get in to allow plants to photosynthesise The plants die Saphratrophic nutrition - bacteria feed on the dead Increases BOD Fish die

Question 29

What happens to the suns radiation when it enters the earth? (Greenhouse effect)

Answer 29

It is reflected off the earths surface, absorbed then re emitted

Question 30

What are greenhouse gases made up of?

Answer 30

Water vapour, carbon dioxide and methane

Question 31

What are some possible consequences of increase in greenhouse gases? (5)

Answer 31

``` Global warming- earth warms up Habitat change Desertification Species loss More flooding ```

Question 32

What is nitrification?

Answer 32

When ammonia is converted to nitrates by nitrifying bacteria

Question 33

Why do farmers grow legume plants in their fields? (5)

Answer 33

Legumes contain nitrogen fixing bacteria in the root nodules Fix nitrogen gas into ammonia Ploughing causes clover plants to decompose Releasing ammonia Increase yield There are mineral ions and nutrients in the soil

Question 34

What is meant by the term double helix?

Answer 34

Two strands linked together

Question 35

Which hormone repairs uterus lining?

Answer 35

Oestrogen

Question 36

Which hormone maintains uterus lining?

Answer 36

Progesterone

Question 37

What is the role of the placenta?

Answer 37

Secretes progesterone so lining stays thick | Prevents embryo from aborting

Question 38

What is the role of the amnion sac?

Answer 38

Secretes amniotic fluid Protects embryo against bumps and jolts Encloses embryo

Question 39

Once the egg is released where does it go?

Answer 39

Travels down oviduct to the uterus

Question 40

What is the role of corpus luteum?

Answer 40

Produces progesterone

Question 41

How do hormones travel from the ovary to the uterus?

Answer 41

In the blood stream

Question 42

How many chromosomes are there in a body cell of the male fetus?

Answer 42

46

Question 43

What is the role of meiosis?

Answer 43

To produce gametes

Question 44

Where does meiosis occur?

Answer 44

In the ovaries and testes or ovary and anther of a plant

Question 45

How many chromosomes are produced in meiosis?

Answer 45

Half the number - haploid

Question 46

What is the purpose of mitosis?

Answer 46

For growth and repair damaged tissue

Question 47

How many chromosomes are produced in mitosis?

Answer 47

Diploid - 1 pair of each chromosome in the nucleus

Question 48

Does meiosis produce genetically identical gametes?

Answer 48

No

Question 49

Does mitosis produce genetically identical cells?

Answer 49

Yes

Question 50

How many chromosomes are there in a human body?

Answer 50

46

Question 51

What are the advantages to a sexual reproduction?

Answer 51

Reproduce v. quickly with no partner needed | Numbers double each generation

Question 52

What are the disadvantages to asexual reproduction?

Answer 52

No variation

Question 53

What is selective breeding and what are 2 examples of its use? (5)

Answer 53

``` Desirable characteristics Prevent breeding with other individuals Repeated for many generations Example- cattle for milk yield - wheat for shortened stem length ```

Question 54

How can bacteria be genetically modified to produce human insulin? (5)

Answer 54

``` Human insulin cut from human chromosomes Using restriction enzymes Plasmid cut open Making sticky ends Using some restriction enzymes ```

Question 55

What is the role of insulin in the body?

Answer 55

Tells liver to take in glucose and covert it to glycogen | Lowering blood glucose levels

Question 56

Describe the stages of cloning in mammals (6)

Answer 56

Egg/ovum removed Nucleus removed Nucleus taken from body cell and inserted into ovum Encleated ovum fused with body cell using electricity Cell divided by mitosis Embryo implanted into uterus of surrogate mother

Question 57

What is a gene?

Answer 57

A code for a certain protein which controls processes in the body

Question 58

What is an allele?

Answer 58

Alternative form of a gene

Question 59

What is a dominant allele?

Answer 59

Expressed when there's a recessive allele present | Version of a gene

Question 60

Why is the number of people who have a rare condition low even though it's a dominant condition? (3)

Answer 60

It's very rare Makes individuals less likely to reproduce So becomes less common every generation

Question 61

What are 2 advantages to micropropagation?

Answer 61

Can produce large quantities | Could lose gene in sexual reproduction otherwise