Biology B2

HideShow resource information
  • Created by: Issynx
  • Created on: 03-11-15 18:18
View mindmap
  • Biology B2
    • Cells
      • Root Hair Cells -Increase surface area
      • White Blood Cells engulf and destroy invading microorganisms
      • Diffusion is the spreading of particles of gas through a substance through the cell membrane
      • Mitochondria - Where energy is released
      • Ribosomes - Where protein synthesis occurs
      • Chloroplasts absorb light energy to make food in a plants (with Chlorophyll)
      • Cells constantly replace substance that are used up and remove other substances
    • Tissues and Organs
      • Muscles tissue contracts so we can move
      • Glandular tissues produces hormones and enzymes
      • Epithelial tissue covers organs
      • Organs are made of tissues
        • Stomach is made of muscle, epithelial and glandular tissues
      • Example of an organ system : Digestive System
      • Plant organs are: Stems, Roots and Leaves.
      • Examples of Plant Tissues are
        • Epidermal Tissues:cover the plant
        • Mesophyll: Where Photosynthesis takes place
        • Xylem and Phloem: Transport substances
    • Photosynthesis
      • Carbon Dioxide + Water = Glucose + Oxygen
      • The glucose may be changed into insoluble starch and stored
      • Used by the plant during respiration to provide energy
      • Plants use nitrate ions from the soil to produce proteins
      • Glucose may be used to:
        • Produce fats and oils
        • Produce cellulose to strengthen cell walls
        • Produce proteins
      • Temperature, Carbon Dioxide concentration and Light Intensity all effect it
    • Distribution of Organisms
      • Physical factors that effect organisms:
        • Temperature
        • Nutrients
        • Light
        • Water
        • Oxygen and Carbon Dioxide
      • Sampling with quadrat finds the mean of a species in a certain area by repeating several times in an area
    • Proteins
      • Long chains of amino acids, allow molecules to fit into the protein
      • Enzymes are proteins that are shaped so i specific substrate can fit into it to cause a chemical reaction
      • High temperatures will change the shape of an enzyme so it wont work (denatured)
        • Different enzymes work best at different temperature and pH levels
      • Different types of enzymes:
        • Protease digests proteins and produces amino acids
        • Lipase digests lipids and produces fatty acids and glycerol
      • Proteins can be used in biological detergents, baby food and  in slimming foods as isomerase
        • Isomerase converts glucose syrup into fructose syrup which is sweeter and can be used in small quantities
      • Where different enzymes are produced:
        • Salivary glands produce amylase which starts to digest carbs
    • Cell Division & Inheritance
      • Body cells contain two sets of 23 chromosomes
      • Gametes are sex cells, they only have one set of 23 chromosomes
      • Mitosis
        • A copy of each chromosome is made
        • The cell  divides once to produce two body cells
        • New cell contains exactly the same genetic information as the parent cell
      • Meiosis
        • Occurs in the testes and ovaries to produce gametes
        • Each chromosome replicates itself and divides for the first time with copies on opposite sides
        • Copies then split up and the cell divides again to create 4 gametes with half the number of chromosomes as the parent cel
      • Females sex chromosomes are identical (X)
      • Males sex chromosomes Y is much shorter than X
      • Half the sperm carry X to make a girl and half carry Y to make a boy
    • Alleles and Genetics
      • Genes have different forms called alleles
      • If alleles are different one will be dominant and one will be recessive
      • The recessive allele will only control the gene if it is present in both chromosomes in a pair
      • Key Terms:
        • Genotype - the combination of alleles
        • Homozygous - 2 copies of the same allele e.g BB or bb
        • Heterozygous - two different alleles e.g Bb
        • Phenotype - The characteristic shown due to the allele combination
      • Stem cells have the ability to develop into any kind of cell
      • Stem cells can be used to treat conditions as they can replace other cells
      • Some times stem cells may be used for research from embryos
        • For: Helps people who are living
        • Against: Embryos should be used as they could damage a potential human life
      • Polydactylyl is caused by a dominant allele
      • Cystic Fibrosis is caused by a recessive allele
    • Speciation
      • Fossils are rare because most organisms were soft bodied and didnt leave traces. Also they may have been destroyed by geological activity
      • Extinction
        • Changes to environment
        • New predators and competitors
        • Catastrophic events
      • New diseases
      • New species happen as a result of isolation
      • Genetic Variation - each population has a wide range of alleles
      • Natural Selection - organisms with desired characters will survive
      • Speciation - Populations become so different interbreeding becomes unsuccessful
    • Respiration and Excersize
      • Aerobic
        • Glucose + Oxygen = Carbon Dioxide + Water + Energy
        • Takes place continuously in organisms
        • Most reactions take place in the mitochondria
        • Energy may be used to:
          • Build larger molecules
          • Allow muscles to contract
          • Maintain steady body temp
      • Anaerobic
        • Glucose = energy + lactic acid
        • Not enough oxygen means anaerobic respiration will take place
        • Lactic acid is the product of a incomplete breakdown of glucose
        • Less energy
      • Heart rate increases and so does rate of breathing
      • Bloodflow to muscles increases
      • Muscles store glucose as glycogen until needed for energy

Comments

Issynx

This mind map includes all the key points from the AQA syllabus. (Information from Collins Revision AQA GCSE Biology Essentials - Revision Guide) I suggest you purchase this!

Similar Biology resources:

See all Biology resources »See all All of B2 resources »