Science Biology Unit 1 Year12

Question 1

Explain how to use a microscope

Answer 1

first put the low power objective lens in place , then place the slide on the stage (then clip) , next adjust the light to full brightness and adjusting the coarse focus wheel , finally using the fine focus wheel to get a clear picture.

Question 2

Define L-dopa

Answer 2

precursor of dopamine , goes into the brain

Question 3

Explain how L-dopa treatment works

Answer 3

converted into dopamine by dopa decarboxylase (enzyme in the brain) , temporarily reduces motor symptoms by increasing dopamine to normal levels , however , only 5-10% of L-dopa is administrated in the brain , effectiveness is reduced as more brain cells die off.

Question 4

Define and explain function of Golgi apparatus

Answer 4

membrane bound organelle found in most cells , responsible for packaging proteins into vesicles prior to secretion , plays a key role in secretory pathway

Question 5

Define and explain how arteriosclerosis develops

Answer 5

blood vessels become thick, blocked by fat restricting blood flow to the rest of the body, high blood pressure and CO damages the inner lining of arteries and then growth of cholesterol

Question 6

What is nervous tissue made out of?

Answer 6

neurons

Question 7

Explain the function of neurons

Answer 7

receive and facilitate nerve impulses , action potentials across their membrane and pass it on to the next.

Question 8

What are neurons made out of?

Answer 8

Soma cell body , Schwann cell with myelin sheaths , the gap between each myelin sheath is a node of Ranvier , small projections called dendrites and axon (axon terminal at the end of one) separated from the dendrite of the next neuron by a synapse gap.

Question 9

Explain how a nerve impulse travels

Answer 9

crosses a synapse in the form of a neuron transmitter , they diffuse across the synapse and initiate an action potential in the neuron on the other side. The pre-synaptic neuron ends up in a synaptic bulb were mitochondria/ATP is needed.

Question 10

Where is a neurotransmitter stored?

Answer 10

temporary vesicles in a synaptic bulb that can fuse to the surface to release

Question 11

Define and state symptoms of Parkinson’s disease

Answer 11

a genetic disease that affects the nervous system to not able to produce natural produce dopamine. For example, slow movement, speech problems, tremors when moving, poor balance.

Question 12

Define dopamine

Answer 12

a chemical and neurotransmitter that helps smooth and normal movements.

Question 13

Name the all muscle tissues

Answer 13

cardiac , smooth , skeletal

Question 14

Explain cardiac tissue and where it is found

Answer 14

in the heart , contracts at a steady rate to make a heartbeat and is involuntary

Question 15

Explain smooth tissue and where it is found

Answer 15

in organs e.g. stomach , bladder and is involuntary

Question 16

Explain Skeletal tissue and where it is found

Answer 16

contracts in order to move bones, lots of mitochondria , made up of lots of myofibrils

Question 17

Features of fast-twitch muscles?

Answer 17

more mitochondria , used in anaerobic exercises , quick release of ATP

Question 18

Features of slow-twitch muscles?

Answer 18

less mitochondria , used in aerobic exercises , quick release of ATP

Question 19

Explain two functions of plasmids in bacteria

Answer 19

carry DNA/genes, antibiotic resistance

Question 20

Why do myelinated neurons conduct impulses much faster than non-myelinated neurons?

Answer 20

impulse jumps over areas of myelin

Question 21

Explain the structure of myelin-sheath

Answer 21

a neuron that consists of fat containing cells which insulate the axon from electrical activity

Question 22

Explain the features of a sperm cell

Answer 22

acrosome (head) contains a enzyme that aids in breaking through the outer egg cell membrane, contains mitochondria in the middle, tail helps with mobility

Question 23

Explain the features of a egg cell

Answer 23

outer membrane which supplies protein to the egg, large cytoplasm and nucleus contains 23 chromosomes

Question 24

Explain the features of a root hair cell

Answer 24

large surface area = increase rate of absorption of water/ions, cell membrane is partially permeable to water, short distance across cell walls to increase rate of diffusion

Question 25

What is the equation for magnification?

Answer 25

actual size

Question 26

Explain the features of lymphocytes T cells and B cells

Answer 26

T sends signals to B, B produces antibodies while T destroys infected/cancerous cells

Question 27

Explain the features of neutrophils

Answer 27

most common white blood cell, flexible and mobile (squeezing through cell in the capillary wall), phagocytic

Question 28

Explain the features of red blood cells

Answer 28

contains haemoglobin, small/flexible to squeeze along capillaries, biconcave meaning large surface ration

Question 29

Explain chronic bronchitis

Answer 29

inflammation of airway in the lungs, squamous epithelium thickens

Question 30

Explain emphysema

Answer 30

damage to air sacs, destroys alveoli walls, decreases surface area, caused by smoking

Question 31

Explain squamous epithelium and its function

Answer 31

Make up the walls of alveoli, which is were oxygen and carbon is exchanged

Question 32

Explain columnar epithelium and its function

Answer 32

Single cell layer of cells lining the trachea, it is covered by cilia and contains goblet cells which secrete mucus for trapping pathogens

Question 33

Explain endothelial and its function

Answer 33

Squamous endothelial is the inner lining of blood vessels

Question 34

State the differences of eukaryotic and prokaryotic

Answer 34

eukaryotic has a nucleus, prokaryotic does not
eukaryotic has mitochondria, prokaryotic does not
eukaryotic has a Golgi apparatus, prokaryotic does not

Question 35

State the similarities of eukaryotic and prokaryotic

Answer 35

Both contain DNA, cytoplasm, ribosomes