B1 revision

Quick recap, question sheets, worksheets

G lucoregulation

B lo od g luco se b ack to n orm a l

G lu ca g on te lls L ive r to b rea k d o w ng lyco g en in to g lu co se a n d re le a se

in to b lo od s tre am

G lu ca g on re le a se d by p an c re a s,in su lin sto pp e d b e in g re lea sed

B lo od G lu co se too low

B lo od g luco se b ack to n orm a l

In su lin te lls L ive r to ta ke g lu co se from b lo o d ,tu rn it in to g luco ge n ,

a n d sto re it in L ive r ce lls

In su lin re le a sed b y P a nc re as

B lo od g lu cose to o h igh

P a nc re as m o n ito rs b lo o d g luco se

Insulin tells Liver to take glucose out of the blood, turn it into glycogen and store it in Liver

cells

Respiration and Pulse Rate• Aerobic respiration:

– Releasing energy from glucose using oxygen.– Occurs in every cell in the body– C6H12O6 + 6O2 → 6H20 + 6CO2

• Anaerobic respiration: – Releasing energy from glucose without oxygen– Produces less energy → less efficient– Produces lactic acid → causes cramp and

muscle fatigue → removed with oxygen (debt)– Glucose → Lactic acid

Pulse rate and blood pressure

• During exercise you need more energy, so need to respire more, so need more oxygen, so breath faster and deeper

• Blood pressure: – Systolic → when heart contracts– Diastolic → when pressure in arteries drops– High BP: Stress, smoking, diet → heart attack– Low BP: Low blood sugar → dizzy and fainting

Food and Digestion• Carb’s: provide energy• Fats: provide insulation and energy• Protein: builds cells & growth and repair• Vit. C: Strengthen skins• Iron: Making haemoglobin• Fibre: keeps digestive system moving

Q: What deficiency diseases do a lack of protein/Vit. C/ iron/ fibre cause?

Kwashiorkor/Scurvy/Anaemia/Constipation

Body Mass Index: BMI

• Mass in kg / (height in m)2

• Should be between 18 and 25

QWhat is the BMI of a person who has a mass of 65kg, and a height on

1.6m?

Enzymes and digestion

Type of food

Enzymes Found in Broken down to

Optimum pH

Starch xxxxxxxCarbohydrase

xxxxxSmall

intestine

GlucoseGlucose

pH 6-7

Proteins Pepsinxxxxxxx

StomachXxxxx

xxxxxxxxx

Xxxxx xxxxxXxxxx xxxxx

pH xpH 5-7

Fats Lipase Small intestine

Xxxxx xxxxx & xxxxxxxx

pH 5-7

Pathogens & Disease

• FoBacteria Virus Fungi Protozoan

Single cell Single cell (v.small)

Single cell Parasite: lives and feeds of & harms host

Survive in most conditions

Not alive: need host cell to grow

Similarities to plant & animal cells

Needs vector to move about

Killed by antibiotics

Not killed by antibiotics

Can mutate to become resistant to drugs

Get immune, but virus’s can mutate

Cholera/T.B/ Food poisoning

Colds/ Flu/ HIV Athletes foot, thrush, ringworm

Malaria

First Response to Disease

Skin:(Thick, strong), (blood clots), (tears)

Gaseous exchange system:(Cilia), (Mucus), (Patrol WBC’S)

Food and Water:(Looks), (Cooking), (HCl in stomach)

Infection

• White blood cells destroy pathogens by:1. Engulfing and ingesting them2. Produce Antibodies which recognise &

attach to the antigens on pathogen and destroy it

3. Produce memory cells which stay in bloodstream on alert for repeat attack (means you are immune)

Immunity

• Once you have an infectious disease, you keep the memory cells & antibodies in you blood meaning you are immune.

• Vaccinations and breastfeeding are 2 ways that we can become immune and have antibodies to a disease without ever having the disease

• Drug resistance & drug testing• Placebo & Double blind test

Suspensory ligaments

Optic nerve

The Eye

Retina

Pupil

Cornea

Ciliary musclesSuspensory ligaments

Optic nerve

Lens

IrisSclera

Accommodation: Eye’s ability to change focus on near or far objects

For distant objects the ciliary muscles

relax and the suspensory ligaments pull tight making the lens pull thin – the

light doesn’t bend as much.

For close objects the ciliary muscles

contract allowing the lens to go fat, thus bending the light

more.

Remember

Nearby objects:• Light rays need lots of refracting, • So lens needs to be thick• Ciliary muscles contract, so suspensory

ligaments slacken

RememberDistant objects:• Light rays parallel, do not need much

refracting, • So lens needs to be thin• Ciliary muscles relax, so suspensory ligaments

tighten

Ciliary Muscles

Ciliary Muscles

Eye Defects

Myopia

• Short-sighted• Eye ball too long• Image is focused

before the retina• Blurred images• Need concave lens

Hypermetropia

• Long-sighted• Lens not thick

enough• Light not refracted

enough• Image is focused

behind the retina• Blurred images• Need Convex lens

Neurones

Nucleus

Cell Body

Myelin Sheath

AxonNerve Endings

Cytoplasm

Cell Membrane

Dendrites

Reflex Arc

Stimulus

Receptor

Effector

Sensory Neurone

Relay Neurone

Motor Neurone

Response

Synapses

• Neurones do not touch each other• They have small gaps in between one another

called synapses• When an impulse has travelled down a

neurone, it stimulates a transmitter substance into the synapse which diffuses across to the next neurone.

• This trigger an electrical impulse in that neurone

Type of drug Effect on the body Named examples

? Slows down the activity of some parts of the brain.

Alcohol, Solvents and Temazepam.

? Reduce sensations of pain, sometimes by blocking nervous impulses.

Aspirin and Heroin.

? Increase activity in the brain.

Nicotine, Caffeine and Ecstasy.

? Increase an athletes performance.

Anabolic steroids.

? Distorts what is really seen/heard.

Cannabis and LSD.

Drugs• Stimulants: Ecstasy, nicotine, cocaine

– Increase brain activity– Increase level of dopamine in neurones– Happier, chattier, energetic, higher blood

pressure and faster heart beat

• Depressants: Alcohol, solvents– Decrease brain activity– Increases GABA (neurone transmitter that

slows down impulse)– Decreases Glutamate (neurone transmitter

that speeds up impulses)

Cigarettes• Cigarettes contain:

– Nicotine: Addictive, increases blood pressure– Tar: Coats lungs and carcinogen– Carbon Monoxide: Reduces oxygen in blood– Particulates: Irritate lungs– Short term: Coughing, bronchitis

• Alcohol: Depressant– Loss of inhibitions and sense– Loss of body heat → hypothermia– Cirrhosis (long term effect on liver)

Homeostasis• “The maintenance of a constant

internal environment”.

• Not just temperature that is controlled• What else is?

• Blood glucose• Water levels• Carbon Dioxide

Negative Feedback

Temperature rises

too high

Shivering generates heat.

Vasoconstriction reduces heat loss through skin

Hypothalamus

senses change in temperature

Skin, Muscles and Vessels: senses change in temperature

Temperature falls too low

Sweat loses heat though evaporation.

Vasodilation increases heat loss

though skin

Do a negative feedback loop for blood glucose control (remember insulin, glycogen, glucagon, pancreas, liver

Genes

• Diploid cells contain 46 chromosomes (2 sets of 23)

• Haploid cells contain 23 chromosomes(1 set of 23)

• Many genes can be found on chromosomes• Genes code for a particular characteristic• A gene which can give a varied outcome is called an

allele (these are either dominant or recessive)

• If you unravel chromosomes, you end up with long double helix strands of DNA

DNA• Double helix strands held together by base

pairs (a-t and c-g)

1. What is different from species in the fungi kingdom, compared to those in the plant or animal kingdoms?

2. How do we know that Lamarck's theory of evolution is wrong?

3. What uses (other than for respiration) does a plant have for glucose?

4. Explain the mutualistic relationship of Nitrogen fixing bacteria and leguminous plants

5. In what type of water would you find Mayfly nymphs?

Answer these questions:

B2ASampling techniques: must be random must be representative of size of area must use appropriate technique• quadrat• pooter• kick sampling• tullgren funnel• nets• pitfull traps

Habitat, niche, ecosystem, population, community

B2B: Classification• Kingdoms (5)• Phylum• Class (five for animals)• Order• Family• Genus Genus + species = binomial name

• Species

(Carl Linnaeus system)

B2B

• Organisms in same species can breed to produce fertile offspring

• Organisms in same genus can breed to produce infertile offspring (Hybrids)

B2C• Photosynthesis =

– plants producing their own food

Carbon + water → Glucose & oxygendioxide

– Happens in chlorophyll in chloroplasts in leaves– Only during day– Plant can store glucose made as starch or use to

make oils, proteins, cellulose in cell walls– Reaction happens fast depending on limiting factors

• Plants need nitrates to grow healthily. They can get these from the soil, but often there isn’t enough in the soil as other plants are competing for them too.

• Legumous plants have a bacteria that lives on their roots. The bacteria can change nitrogen in the air into nitrates for the plant to use. Now the plant doesn’t have to compete with other plants. The bacteria feeds on sugars that the plant produces.

• What type of relationship do the plants and nitrogen fixing bacteria have? (parasitic or mutual?)

Relationships

Relationships

• Between species or species with similar niches• Competition (for what?)

• Predator/prey (features of both)• Cycle (why more prey? Why out of sync?)

• How is a polar bear adapted to survive?• How is an insect pollinated plant adapted to

survive?

Adaptations

Is this plant adapted for insect or wind pollination?Why?

• A rabbit has all round vision, where as a fox has binocular vision. How do this adaptation help both animals?

• Dolphins are mammals and shark are fish. Explain why dolphins are classified mammals, but also why they look like most fish?

Adaptations

Fossils• Remains of marine organisms (or imprints)

• When decay hasn't happened (oxygen/moisture/pH)

• Fossil record incomplete (not all species fossilised, not all found, destroyed/distorted)

• Provide evidence for evolution

Natural selection

• Darwin's idea for evolution– Variation (due to mutation)– Some variations better (competition)– More likely to be passed on to next generation– Over many generations– New species formed eventually– Speciation

Charles Darwin & evolution • What were the conclusions in his book (The

Origin of Species)?• Why did his book cause controversy? • What similar theory did Jean-Baptist Lamarck

have before Darwin? • How do we know that Lamarck’s theory is

incorrect, where as Darwin’s is still believed today?

• Carbon Dioxide:

• Released when we burn fossil Fuels• Taken in by plants, so deforestation increases amount in

atmosphere.

• Increases global temperature because it is a greenhouse gas

• What is a greenhouse gas?

• Causing global warming

Pollution

• Sulphur Dioxide (SO4)

• Released when we burn fossil fuels/coal• Mixes with rain to form sulphuric acid• Acid rain• Destroys plants, fish, water and buildings• Kills lichen on trees (so they can be indicator

species for it)

Pollution

• CFC’s

• Released from decaying polystyrene, leaky fridges and freezers, and aerosols

• Breaks down and damages ozone layer (O3)• Lets more harmful UV rays in• These cause skin cancer

(nothing to do with CO2 or global warming!!!!!!)

The ozone layer

Sustainability

• Using something at a rate so it will not run out in future

• Fishing quotas, planting new trees after logging

Human population is growing unsustainablyexponentially (doubling & doubling)

Protection

• Endangered species;– Conservation, education, zoos, captive breeding,

red list