b1 you and your genes
DESCRIPTION
Nitrogen bases: Adenine pairs with Thymine Guanine pairs with cytosine. Human male chromosome s. DNA is a double helix Genetic instructions are in the form of a code made up of 4 bases. DNA with bases. Inheritance- Parents who are both carriers of the Cystic fibrosis allele (c). - PowerPoint PPT PresentationTRANSCRIPT
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