exam

Question 1

somatic and germline differences

Answer 1

somatic: occurs in body cells
not inheritable

germline: occurs in reproduced cells
inheritable

Question 2

4 ways antibodies can act

Answer 2

causes particles to clump together- agglutination

coat bacteria so more easily consumed by phagocytes

dissolve organisms

bind to the surface of viruses and prevent them from entering cells

Question 3

how does the PH of blood alter

Answer 3

CO2 is a product of so respiration
Carbon dioxide combines in water to form carbonic acid which dissociates to form HCO3 irons and hydrogen irons.
as hydrogen ion concentration in the blood increases blood ph decreases
stimulates aortic and carotid bodies

Question 4

sickle cell symptoms

Answer 4

fatigue, thirst , joint pain,

Question 5

gene and chromosomal mutations differences

Answer 5

gene - changes in a single gene so that the traits normally produce by that gene are changed or destroyed

chromosome- all part of a chromosome is affected.

Question 6

gene therapy good for

Answer 6

Cystic fibrosis
Huntington’s disease
sickle cell Armenia
type 1 diabetes

Question 7

difference in diabtetes 1 and 2

Answer 7

1: childhood - the destruction of beta cells in the islets of Langerhans. Beta cells produce insulin therefore a person with type one diabetes does not produce insulin

2: adult- cells do not respond to insulin.

affects- kidney failure, stroke, heart attack

Question 8

hyperthyroidism and hypothroidism symptoms

Answer 8

hyperthyroidism- rapid heartbeat, weight loss, increased appetite, fatigue, sweating, anxiety protruding eyeballs

hypothroidism- slow heart rate, weight gain, fatigue lack of energy, swelling of the face and qoitre

Question 9

Two advantages and one disadvantage of mitochondrial DNA to DNA

Answer 9

Advantage, lots of mitochondria equals lots of DNA, higher mutation rate.

disadvantage- male side - father

Question 10

vaccines have in common

Answer 10

Weakened virulence by chemicals
Provide memory cells
given before catching the disease
artificial
active
can be injected

Question 11

living attenuated

Answer 11

Micro organisms with ability to produce disease symptoms. Therefore the immunised person does not contract the disease but manufacture of antibodies against the antigens

Examples are polio + measles

-last longer
Provide a stronger immune response

Question 12

inactivated vaccine

Answer 12

Contain dead micro organisms. Produce immunities should’ve lost and then immunisation using living attenuating micro organisms. Whooping cough

Question 13

toxiod

Answer 13

Toxins produced by the bacteria can be activated so that when injected into someone and you do not make the person feel such as ill. called toxoids. Tetanus

Question 14

Sub unit vaccine

Answer 14

Fragment of the organism can be used to provide to him in response. Hepatitis B.

Question 15

homo neanderthal vs sapiens

Answer 15

neanderthal - short stocky
no chin
occipital bun
mousterian

sapiens
no occipital bun
in present
taller thin
aurignacian

Question 16

thalassima b

Answer 16

Beta thalassaemia is due to a mutation in the HBB gene on chromosome 11 this reduces the level of beta Globin in the haemoglobin.

\More prevalent in the Mediterranean basin

Question 17

thalessima A

Answer 17

Alpha thalassaemia is due to mutation in the HBA on chroma zone 16 this reduces the level of alpha Globin in haemoglobin

More prevalent in South East Asia

Question 18

What is thalassaemia

Answer 18

An autosomal recessive gene that alters the structure of haemoglobin which therefore means the victims cannot carry as much oxygen in the blood

Question 19

what is tay sachs

Answer 19

Lethal condition caused by mutation that results in the absence of enzyme better hexominisades

Leads to the deterioration of the nervous system and death usually occurs at a young age

People who are heterozygous have a reduced amount of better hexominisades which provides them protection from tuberculosis.

Question 20

genetic drift

Answer 20

The random, non-directional changes in a little frequency between generations. Purely by chance is it Cousin populations of all sizes.

Question 21

founder effects and what it causes new groups to have

Answer 21

When a small group moves away from its homeland to a totally new area and establishes a population.

It will have a different a low frequency from the original population.
It will decrease genetic variation.

Question 22

Bottle neck

Answer 22

Extreme example of genetic drift wet situations such as a natural disaster severely reduces the size of the population.

Question 23

Speciation steps 4

Answer 23

Variation – a population exists on an island

Isolation the species is divided into two populations which gives them different gene pools

Selection – two subspecies begin to form this is due to different selection pressures and brings change engine frequencies

Speciation – two species now exist as jeans pink which is maybe great enough to prevent production of photo offspring but interbreeding in between the two populations.

Question 24

pcr steps

Answer 24

Polymerase chain reaction mimics the process of DNA replication

Denaturation - two strands of DNA are separated and proper proximately 94 to 96°C this breaks the hydrogen bonds holding this two strands together

Annealing – temperature decrease to 50 to 60°C and short sections of DNA primers are bound to separate strands and a complimentary to the DNA being copied

Extension – the enzyme DNA polymerase is used to join you complimentary nucleotides to the originating sections with partners this happens in around 68 to 72°C.

Question 25

9 adaptations hominid for erect posture

Answer 25

Foreman magnum – located centrally in the base of the cranium
Jawbone – small and non-protruding, enabling the skull to balance on the veterbral column
Vertebral column – lumbar vertebrae wedge shaped, producing S shaped curve that brings vertebral column directly under the centre of the skull.

Pelvis – broad; shallow from top to bottom. Provide support for abdominal organs. Attachment of famous is wide apart contributing to the carry angle

femur - large head of femur contribute to carrying angle

Knee joint – outer hinge larger and stronger, to take weight of body knee is able to be straightened

Legs – longer than arms, contributing to low centre of gravity. Carrying angle allows the weight of the body to be kept close to the central axis

Foot - large heel bone and a line big toe for a pedestal on which the body is supported, foot has both longitudinal and transverse arches

Muscle tone – partial contraction of muscles to support the spine hip knee and ankle

Question 26

synapse transmission

Answer 26

action potential arrives at pre-synaptic knob/axon endings calcium ions flow into pre-synaptic knob/exocytosis of vesicles containing neurotransmitter
neurotransmitter diffuses across gap/synapse
neurotransmitter binds to receptors on post-synaptic membrane/ dendrite of next neuron
ion channels on the post synaptic membrane open/causes an influx of sodium ions/triggering depolarisation/triggering action potential

Question 27

8 points Explain how different antibiotics can be used to treat infections

Answer 27

antibiotics target disease-causing bacteria
can be broad spectrum/affect a wide range of bacteria
or can narrow spectrum/effective only against specific types of bacteria (bacteriostatic) antibiotics inhibit the growth of bacteria
by interfering with protein synthesis
(bactericidal) antibiotics destroy bacterial pathogens
by targeting cell walls, cell membranes or
metabolic pathways/action of enzymes found inside bacteria

Question 28

Describe the physiological mechanisms that cause fever 8 marks

Answer 28

hypothalamus increases thermostat setting of body (person feels cold)
pyrogens released
Produced by white cells or pathogens
muscles begin to shiver
blood vessels constrict
both processes help to drive up body temperature
macrophage engulfed pathogen
macrophage stimulated to release interleukins/cytokines interleukins/cytokines enhance the pyrogens

Question 29

(a) hGH is released from the pituitary gland. State from which lobe of the pituitary this hormone is secreted and explain the relationship between this section of the pituitary
gland and the hypothalamus. 6 points

Answer 29

secreted from the anterior lobe
communication between the hypothalamus and the anterior pituitary occurs through chemicals/hormones
through the infundibulum/blood vessels
hypothalamus stimulates the anterior pituitary to release hormones via releasing factors/hormones
the hormones are released into a capillary network and transported through veins
also produces inhibiting factors to inhibit activity of the pituitary

Question 30

Explain how hGH enters and affects the functioning of ts target cell.
6 pints enters and affects

Answer 30

dissolve in water (not fats) so cannot pass through cell membrane hormone molecule attaches to receptor molecule
receptor molecule found on surface of target cell

inding of hormone to receptor triggers a secondary messenger/response inside the cell
secondary messenger activates enzymes inside the cytoplasm
enzymes adjust chemical activity of the cell

Question 31

Explain how the process of natural selection can lead to a particular phenotype
becoming prevalent in a population

1mark 3 mark 6mark.

Answer 31

variation present in individuals

limited resources available
selection pressure present
competition for resources/struggle to survive

genes passed to offspring
a particular phenotype is more suitable for the environment
individuals that do not possess the phenotype (genes) die-off
individuals that do possess the phenotype (genes) survive/survival of the fittest
over time more individuals have more suitable characteristics
after many generations, the particular phenotype is more prevalent

Question 32

carbon 14 process 4 marks

Answer 32

Based on the decay of carbon-14 into nitrogen
Amount of carbon-14 is fixed at death
The ratio of carbon-14 to carbon-12 determines the age Carbon-14 has a half-life of 5730 years