Biology Paper 2

Question 1

What is homeostasis?

Answer 1

The regulation of internal conditions of a cell or organism in response to internal or external changes

Question 2

What does homeostasis control?

Answer 2

Blood glucose concentration
Body temperature
Water an ion levels

Question 3

What is the order of the negative feedback system of control system?

Answer 3

Stimulus 
Receptor
Sensory neurone
Relay neurone
Motor neurone
Effector
Response

Question 4

What controls body temperature?

Answer 4

The thermoregulatory centre

Question 5

If temperature is too high?

Answer 5

Vasodilation

Question 6

If temperature too low?

Answer 6

Vasoconstriction

Question 7

What does the cerebral cortex control?

Answer 7

Consciousness, intelligence, memory and language

Question 8

What does the cerebellum control?

Answer 8

Coordination

Question 9

What does the medulla control?

Answer 9

Automatic action

Question 10

What does the retina do?

Answer 10

Contains reception cells that are sensitive to light

Question 11

Optic nerve

Answer 11

Carries impulses from retina to the brain

Question 12

Sclera

Answer 12

Tough outer layer with transparent region called cornea

Question 13

Iris

Answer 13

Controls size of pupils and amount of light reaching retina

Question 14

Ciliary muscled and suspensory ligaments

Answer 14

Change shape of lens to focus light

Question 15

What is Accommodation?

Answer 15

Process of changing shape of lens to focus on objects

Question 16

What is myopia?

Answer 16

Short sightedness

Question 17

What’s hyperopia?

Answer 17

Long sightedness

Question 18

Which system is faster?

Answer 18

The effects of the hormones are slower and act for longer

Question 19

What does Thyroxine do?

Answer 19

Increase metabolic rate
Controls growth and development in young
Controlled by negative feedback

Question 20

What happens in blood glucose is too low?

Answer 20

Release glucagon

Glucagon stimulates glycogen to convert back to glucose

Question 21

What controls the balance of water?

Answer 21

Kidneys

Question 22

What is urea?

Answer 22

Produced by liver from breakdown of proteins and contains nitrogen

Question 23

What are excess amino acids converted to?

Answer 23

Ammonia in process called deamination

Question 24

Urine produced by

Answer 24

Filtering blood
Selective reabsorption
Urea and excess water and ions

Question 25

Where does production of urine take place?

Answer 25

Tubules

Question 26

What is ADH?

Answer 26

Released by pituitary gland when blood con. too high | Cause more water to be reabsorbed

Question 27

What does a dialysis machine do?

Answer 27

Takes over role of kidneys

Question 28

What is FSH?

Answer 28

Produced by pituitary gland Causes eggs to mature Stimulates ovaries to produce oestrogen

Question 29

What is Oestrogen?

Answer 29

Produced by ovaries Inhibits FSH Stimulates LH Makes lining grow

Question 30

What is LH?

Answer 30

Produced by pituitary gland | Stimulates release of egg

Question 31

What is Progesterone?

Answer 31

Produced by empty follicle in ovaries Maintains lining Inhibits FSH and LH

Question 32

What does the combines pill contain?

Answer 32

Oestrogen and progesterone

Question 33

What does a implant contain?

Answer 33

Progesterone

Question 34

What is IVF?

Answer 34

Gives a woman LH and FSH to grow many eggs Collect eggs Fertilise eggs with sperm Insert embryos into womb

Question 35

What is a tropism?

Answer 35

Response involving growth in a direction

Question 36

Gravitropism in shoots

Answer 36

Away=negatively

Question 37

Gravitropism in toots

Answer 37

Towards=positively

Question 38

Phototropism I’m shoots

Answer 38

Towards=positivity

Question 39

Phototropism in roots

Answer 39

Away=negatively

Question 40

What are gibberellins?

Answer 40

Plant hormone important in germination

Question 41

What is ethane?

Answer 41

Gas and hormone controls cell division and ripening of fruits

Question 42

Auxins are used as

Answer 42

Weed killers, grow too fast Rooting powders Promoting tissue culture

Question 43

Gibberellins are used for

Answer 43

End seed dormancy Promote flowering Increase fruit size

Question 44

Advantages of sexual reproduction

Answer 44

Variation If environment changes, survive Selective breeding

Question 45

Advantages of asexual reproduction

Answer 45

One parent More time and energy efficient Faster Identical offspring

Question 46

What is a genome

Answer 46

Organisms entire genetic material

Question 47

What is DNA

Answer 47

Polymer made up of nucleotides

Question 48

What does a nucleotide contain?

Answer 48

A sugar A phosphate One of 4 base; A, C, G or T

Question 49

What bases attract

Answer 49

C links with a G | T links with an A

Question 50

How is a protein made?

Answer 50

Proteins synthesised Carrier molecules bring amino acids in correct order Chain down, folds Unique shape to do jobs

Question 51

Who was Gregor Mendel?

Answer 51

Originally, blend of characteristics Breeding on pea plants Units called genes Not recognised though

Question 52

What is an allele?

Answer 52

Different forms of genes

Question 53

What is a genotype?

Answer 53

Combination of alleles present in a gene

Question 54

What is a phenotype?

Answer 54

How the alleles are expressed

Question 55

What is homozygous

Answer 55

Same alleles

Question 56

What is heterozygous

Answer 56

Different alleles

Question 57

What is monohybrid inheritance

Answer 57

Only one gene involved

Question 58

What is polydactyl

Answer 58

Extra fingers or toes caused by dominant alleles

Question 59

What is cystic fibrosis

Answer 59

Disorder of cell membranes cause by recessive alleles

Question 60

How are fossils formed?

Answer 60

Hard parts of animals that do not decay easily Parts of organisms that have not decayed Parts of organisms replaced by other materials Preserved traces of organisms

Question 61

What is selective breeding?

Answer 61

Choose parents by characteristics Breed together Offspring choose desired and breed Continue and repeat

Question 62

What is genetic engineering?

Answer 62

Enzymes used to isolate gene Gene inserted into vector Vector used to insert gene into cells

Question 63

Cloning

Answer 63

``` Remove nucleus from unfertilised egg cell Insert nucleus into adult body cell Stimulate egg to divide Allow embryo to develop Insert embryo into surrogate ```

Question 64

Principles of classification

Answer 64

Kingdom-phylum-class-order-family-genus-species

Question 65

What is the binomial system

Answer 65

First part=genus | Second part=species

Question 66

Three domain system is divided into

Answer 66

Archaea Bacteria Eukaryota

Question 67

What is speciation?

Answer 67

Populations physically isolated Variation present Natural selection operates differently Populations so different inter breeding not possible