Mass and balance
BIO DIVERSITY Variation = differences btwn organisms; physical (size, colour, shape) or behavioural.~Interspecific = btwn species. Intraspecific = within same species.~Species = organisms that can interbreed + produce fertile offspring.~Biodiversity = variety of life; ↑ variation = ↑ biodiversity.~Adaptation = variation that improves survival/reproduction.• Structural = physical trait• Behavioural = action/behaviour~Natural Selection: helpful variation → survive/reproduce → trait passed on → trait becomes common.~Speciation = populations become so different they can no longer interbreed.~Evolution = change in species over time.~High biodiversity = more resistant to disease/environmental change.~Diversity Index = # species ÷ total # organisms~High index = healthy ecosystem. NICHE & SYMBIOSIS~Niche = role in ecosystem:~habitat + food + predators + reproduction.~Generalist = broad niche; many habitats; less extinction risk.~Specialist = narrow niche; thrives in 1~habitat; higher extinction risk.~Symbiosis = close relationship btwn species.~Mutualism = both benefit (humans + gut bacteria).~Commensalism = 1 benefits, other unaffected (remora + shark).~Parasitism = 1 benefits, other harmed (mosquito + mammal). PASSING IT ON~Heritable = passed thru genes.~Asexual Reproduction:• 1 parent• offspring = clones• fast, no mate needed• low variation~Binary Fission = cell copies DNA, splits in 2.Budding = bud grows, detaches.~Spores = fungi release spores.~Vegetative Reproduction = runners, bulbs, tubers, cuttings.~Sexual Reproduction:• 2 parents• offspring = 50% DNA from each• ↑ variation• requires mate/time/energy~Gametes = sperm + egg.~Zygote = fertilized egg.~Gymnosperms = naked seeds in cones (pine, spruce).~Angiosperms = flowering plants; seeds in fruit.~External Fertilization = outside body (fish, amphibians).~Internal Fertilization = inside body (mammals, birds, insects).GENETICS~Gene = section of DNA controlling trait.~Allele = form of gene.~Discrete Variation = limited choices (blood type, attached earlobes).~Continuous Variation = range of values (height, skin colour).~Humans = 46 chromosomes = 23 pairs.~Dominant = capital letter (B).~Recessive = lowercase letter (b).~Genotype = allele combo.~Phenotype = expressed trait.~BB = homozygous dominant.~Bb = heterozygous.~bb = homozygous recessive.~Nature = genetics.~Nurture = environment.~Epigenetics = environment affects gene expression.~Mutation = DNA change.~Mutagens = UV, X-rays, chemicals. DNA & CHROMOSOMES~DNA = hereditary material.~Chromosome = coiled DNA.~Gene = section of DNA coding for protein.~DNA = double helix. Bases: A ↔ T G ↔ C~Mitosis:• growth• repair• maintenance• 1 division• 2 identical cells~Meiosis:• produces gametes• 2 divisions• crossing over• 4 cells w/ half DNA• increases variation~Fertilization: sperm + egg → zygote → embryo → fetus.~Genetic Engineering = altering genes for desired traits.~GMO crops: ↑ yield, disease resistance, drought tolerance, nutrition. ~Matter = anything with mass & volume~Tiny particles..Spaces between particles, Particles move constantly, Particles attract each other, Heating = faster movement~States of Matter.. Solid = fixed shape & volume Liquid = fixed volume, changes shape Gas = no fixed shape or volume~Pure Substance:
One type of particle, Element or compound~Mixture:
More than one substance~Mechanical mixture = visible parts~Solution = evenly mixed~Elements:Made of one type of atom, Cannot be broken down chemically, Example: Au, O, Fe~ Compounds: 2+ elements chemically combined, Example: H₂O, CO₂~ Periodic Table: Atomic number = protons, Period = row, Group = column, Metals = left, Non-metals = right, Metalloids = staircase~ Physical Change:No new substance,Change in size, shape, state, Example: melting ice~ Chemical Change:New substance formed..
Signs:
Colour change, Gas/bubbles, Precipitate (solid forms), Odour change, Light/heat produced~Chemical Equations: Reactants → Products, Reactants = starting substances, Products = new substances~Endothermic:Absorbs energy
,Feels cold~ Exothermic:Releases energy,Feels warm~ Types of Reactions..
Formation
A + B → AB~Decomposition:
AB → A + B~Single Replacement:
A + BC → AC + B~ Combustion:
Fuel + O₂ → CO₂ + H₂O~ Reaction Rate..Faster with: Higher temperature,More concentration, More surface area, Stirring~Catalyst:Speeds up reaction,Not used up~Enzymes = biological catalysts