B1, B2, B3 Revision

RN

B1 Understanding ourselves

Aerobic respiration:Glucose + oxygen Carbon dioxide + water + energyExercise creates an oxygen debt

Anaerobic respiration:Glucose Lactic acid + energy•Much less energy released than aerobic respiration•You breathe heavily to replace oxygen•Heart beats faster so blood carries lactic acid away to liver to be broken down

BP: measured in mmHgSystolic pressure: maximum pressure the heart producesDiastolic pressure: blood pressure between heart beats

Measuring fitness: Strength, flexibility, stamina, agility, speed

BMI= mass (Kg) height (m)2

RDA: Recommended daily allowance

RDA(g) = 0.75X body mass (Kg)Types of cancer:Benign tumours are slow to divide, harmless and do not spreadMalignant tumours are cancerous, divide out of control and spread throughout the body

Carbohydrase (produced in the mouth, pancreas and small intestine) breaks _______ (a carbohydrate) down into

glucose:

Protease (produced in the stomach, pancreas and small intestine) breaks _______ down into amino acids:

Lipase (produced in the pancreas and small intestine) breaks fats (_____) down into fatty acids and glycerol:

Words – blood, lipids, proteins, digestion, starch, smaller

Inheritance- Parents who are both carriers of the Cystic fibrosis allele (c).

Parents Cc x Cc

Gametes C or c x C or c

(egg/sperm) C c

Possible Outcomes C

75% Normal c

25% sufferers

CC

Cc

Cc cc

Protein deficiency - Kwashiorkor

R.Narasimhan

Cystic Fibrosis

Caused by recessive allele (so two copies of allele are needed).

A thick sticky mucus is produced affecting air passages and digestive systems

Controlling Blood SugarControlled by the pancreas, diabetics do not produce enough insulinTreatmentsInjections or monitoring diet

Normal blood glucose level

Normal blood

glucose level.

Insulin produced by the pancreas causes glucose to change to glycogen

Glucagon released and glycogen converted back to glucose

Glucose rises (eat food)

Glucose falls (exercise)

Step 1: The lymphocyte “sees” the pathogen

(microbe)

Step 2: The cell produces antibodies

to “fit” the pathogen

Producing antibodies

Step 3: The antibodies fit onto the pathogens and cause them to “clump”

Step 4: The pathogens are “eaten” by the white blood cells

Reflex action: Stimulus receptor sensory neurone relay neuron in spinal cord motor neurone response

Concave lens and convex lens corrects refraction of light rays so the image lands on the retina

Temperature

Monitored by thermoregulatory centre in brain and receptors in skin.

Too Hot

-hair lies flat

-blood vessels dilate so heat lost through skin

-sweat produced

Too Cold

-goosebumps & hairs trap air

-blood vessels constrict

-no sweat

-shiver, respiration releases heat

Class A Class B Class C

Example Ecstasy, LSD, heroin, cocaine, crack, magic mushrooms, amphetamines (if prepared for injection).

Amphetamines, Cannabis, Methylphenidate (Ritalin), Pholcodine.

Tranquilisers, some painkillers, Gamma hydroxybutyrate (GHB), Ketamine.

Possession Up to seven years in prison or an unlimited fine or both.

Up to five years in prison or an unlimited fine or both.

Up to two years in prison or an unlimited fine or both.

Dealing Up to life in prison or an unlimited fine or both.

Up to 14 years in prison or an unlimited fine or both.

Up to 14 years in prison or an unlimited fine or both.

Damaged cilia in a smoker’s air way

Vasoconstriction and Vasodilation

Hormones of the menstrual cycle

DNA with bases

Human male chromosomes

Lobed ears are dominant over ears with no lobes

B2 Understanding the environment

NATURAL SELECTIOND______ proposed the theory of e______ to explain how species change over time. There is v_______ between individuals, those that are better a_______ are more likely to s________ and r________, passing on favorable characteristics.

HUMAN EVOLUTION

How are human beings different from apes?• bigger b_____• w_____ upright

EVIDENCE OF EVOLUTIONWhat evidence is there that evolution is happening?

CHARLES DARWIN: Developed theory of natural selection based on survival of fittest•Genes pass on the successful characteristics to the next generation

COMPETITIONWhat resources are plants and animals in competition for?• Space • Food• Mate

Fossil record is incomplete because:•Some body part decay quickly•Fossilisation is rare•There may still be fossils we have not found

EXTINCTIONCauses of extinction:• increased c_______• New p________• e_________ change• new d_________

LAMARCKBelieved that acquired characteristics can be inherited

LINCOLN INDEX: Population =Number of animals number of animalsCaught 1st time X caught 2nd timenumber of marked animals caught second time

NATURAL ECOSYSTEMOcean, dessert, grass land, rain forestARTIFICIAL ECOSYSTEMFarm land, Aquarium, green house

Vertebrate group Description

Fish Has scales and gills

Amphibian Has moist permeable skin

Reptile Has dry scaly skin

Bird Has feathers and a beak

Mammals Has fur and feeds young on milk

Invertebrate Vertebrate

No back boneExample: Worms, insects

Back bone presentExample: Humans, fishes

PHOTOSYNTHESIS : Carbon dioxide + water ------ glucose + oxygen

MUTUALISM: When both Organisms benefit, example: Pea plant and nitrogen – fixing bacteria

The presence or absence of an indicator species is used to estimate levels of pollution Example: Lichens

Sustainable development is taking things from the environment but leaving enough behind to ensure a supply for the future and prevent damage

Adaptation: features which help a plant or animal survive in an extreme environment,. Example: Polar bear, Camel and cactus

The up and down pattern of predator and prey population is called cyclic fluctuations

Photosynthesis happens only during day but respiration happens both during day and night

“Species” means “a group of similar organisms” which are capable of interbreeding to produce fertile offspring, e.g. dogs

Hybrids:Hybrids are the result of breeding two animals form different species, they cannot reproduce and are sterile. Example: Tiger +Lion = Tigon

+ =

Labrador Poodle Labradoodle

Liger

GeepZebroid

Mule

Reproduction between species

Organism

Plants Animals

Vertebrates Invertebrates

Reptiles FishBirds Mammals

Amphibians

Have backbon

e

No backbon

e

Classifying organisms

Photosynthesis

glucose

Oxygen

Used to make plant proteins for plant growth

Used as energy

Used to make cellulose for plant cell walls

Stored as starch

Stored as fats and oils

Used in respiration Released into air

Direct products of photosynthesis

Ecological niche: The role of an organism in an ecosystem is called its ecological niche.Example: Native red and American grey squirrels. In Britain, there are 2 types of squirrels which occupy same ecological niche and there is a competition leading to decline in number of red squirrels.

Cytoplasm: chemical reactions take placeCell membrane: Controls movement into and out of the cellNucleus: contains genetic informationMitochondria: Respiration takes place providing energy

Nitrogen bases:Adenine pairs with ThymineGuanine pairs with cytosine

DNA is a double helixGenetic instructions are in the form of a code made up of 4 bases

Protein synthesis:Each gene codes for a particular protein

B3 Living and growing

Haemoglobin + oxygen Oxyhaemoglobin

Platelets: are tiny pieces of cell, which have no nucleus. Important for clottingPlasma: straw coloured liquid which transports carbon dioxide, glucose, waste products, hormones and antibodies White blood cells: protect body against diseaseRed blood cells: transport oxygen from lungs to the tissues, disc shaped and no nucleus

Heart pumps blood around the bodyArteries transport blood away from the heartVeins transport blood into the heartCapillaries exchange materials with tissues

Mitosis-used for normal cell growth

1) Parent cell2) Chromosomes

make identical copies of themselves

3)They line up along the centre

4) They move apart 5)Two daughter cells

form each with 46 identical chromosomes to the parent cell

Meiosis –used to make the sex cells (gametes)-the chromosomes are copied-cell divides twice to give four cells

Enzymes and digestionLarge molecules are broken down so they can be absorbed.-Amylase breaks down starch into sugars in the mouth and small intestine. -Proteases breakdown proteins into amino acids in the stomach and small intestine. -Lipases breakdown fats into fatty acids and glycerol in the small intestine.

1) 2) 3)

Enzymes –biological catalysts that speed up reactions e.g. respiration in the mitochondria

1) Enzyme and substrate

2)Substrate binds to active site

3) Substrate is broken down

Enzymes have an optimum temperature and pH. Changes in pH/temp can denature the enzyme so its shape changes and the substrate can’t bind to the active site

Uses of Enzymes

-Biological washing powders

-In baby foods

-In slimming foods- fructose is made using isomerases. Fructose is sweeter than glucose so less is needed.

Used in lungs O2 diffuses into the blood and CO2 diffuses into lungs

Cell WallCell Membrane

NucleusVacuole

ChloroplastCytoplasm

Photosynthesis

Carbon dioxide + Water Glucose + Oxygen

Light and chlorophyll are also needed

3 Limiting factors -light

-temperature

-CO2

At first as CO2

increases so does photosynthesis

but only up to a certain point

Here light or temperature is the limiting factor.

Cell division

Cell expansion

Cell differentiation

Cell growth