B1 You and Your GenesInheritance- Parents who are both carriers of the Cystic fibrosis allele (c). Parents Cc x CcGametes C or c x C or c (egg/sperm) C cPossible Outcomes C75% Normal c25% sufferers

CC

Cc

Cc cc

Lobed ears are dominant over ears with no lobes

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

DNA with bases

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

Protein synthesis:Each gene codes for a particular protein

Cystic FibrosisCaused by recessive allele (so two copies of allele are needed).A thick sticky mucus is produced affecting air passages and digestive systems

Human male chromosomes

Huntington's Disease Caused by dominant allele (one copy of allele are needed).Loss of memory and neurone damage in the brain

Genetic TestingTo determine any faulty alleles being passed on

PGD - Used to screen embryos for faulty alleles

Stem cells - cells with no specific function. Can be turned into any cell

Variation – caused by dominant/recessive alleles and environment

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

TemperatureMonitored by thermoregulatory centre in brain and receptors in skin.Too Hot-hair lies flat-blood vessels dilate so heat lost through skin-sweat producedToo Cold-Goosebumps & hairs trap air-blood vessels constrict-no sweat-shiver, respiration releases heat

Vasoconstriction and Vasodilation

B2 Keeping Healthy

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

Damaged cilia in a smoker’s air way

Vaccines – dead or live proteins injected into the body. The body will make antibodies for the antigens of the microbes.

Resistant Bacteria's – these are bacteria's that have mutated and antibiotics no longer are able to kill them.

Water Homeostasis – controlled by negative feedback of ADH.

Cause/CorrelationA factor that can cause an outcome. Correlation means that there is a common link between a factor and outcome.

Risk Factor – when you increase the risk of getting the disease by doing the factor i.e. drinking alcohol

B3 Life on Earth

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

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

Vertebrate group Description

Fish Has scales and gillsAmphibian Has moist permeable

skinReptile 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

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

Liger

GeepZebroid

Mule

“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

Organism

Plants Animals

Vertebrates Invertebrates

Reptiles FishBirds Mammals

Amphibians

Have backbon

e

No backbon

e

Classifying organisms

Interspecific Competition – between two different speciesIntraspecific Competition – between the same species

Biodiversity – different species living in the same habitat/ecosystem.

Origin of SpeciesNitrogen & Carbon Cycle – how these elements form a cycle, uses of decomposition, respiration, consumption and photosynthesis