Paper 1

• The cell membrane is a selectively permeable barrier that surrounds the cell and regulates the movement of substances in and out of the cell.
• Mitochondria produce energy through aerobic respiration.
• The nucleus is the control centre of the cell, containing DNA.
• Chloroplasts are responsible for photosynthesis, which converts light energy into chemical energy.
• Ribosomes synthesize proteins using information from DNA and RNA.
• DNA is two strands coiled to form a double helix strand linked by a series of complimentary base pairs join together by weak hydrogen bonds
• A genome is the entire genetic material of an organism
• Ethanol is a substance that causes DNA to precipitate
• A gene is a section of DNA that codes for a specific protein.
• DNA Practicle -Mash or chop fruit or vegetable (e.g kiwi) and mix with salt to clump up the DNA and detergent to break drown the cell membrane and help release the DNA from the nuclei.-Add protease enzyme to the filtered mixture to break down protein. -Add ice cold ethanol carefully down inside the test tube. The ethanol precipitates the DNA forming a fibrous white solid. -Use a glass rod to collect the DNA sample
• These are the 4 bases pairs of DNA Andenine, Thymine, Cytosine, Guanine
• The four bases pair up as follows Adenine always pairs with thymine and cytosine always pairs with guanine
• Mutation is a random change to the base sequence in DNA, which result in genetic variation
• The three types of Gene mutation is insertion, deletion And substitution
• insertion mutation is an extrase base added in
• Substitution mutation is wrong based match
• The deletion mutation is a base removed
• The human genome project is scientific research project involving data of scientist across the globe, which successfully map the entire genome
• Advantage of mapping of genome is

  1-search for genes linked to different diseases,

  2-understand inherited disorders and treatment

  3- trace human migration patterns from the past
• Nucleotide is a monomer of DNA
• DNA nucleotides are made up of common sugar, phosphate group and one of four bases
• Did two stages of protein synthesis is transcription and translation
• Transcription involves the formation of mRNA from a DNA template
• The difference between mRNA and DNA is mRNA is single-stranded where a DNA is double-stranded mRNA uses you as DNA uses T
• Translation involves a ribosome joint amino acid in a specific order, dictated by mRNA to form a protein
• The two types of variations are genetic and environmental
• And allele is each different version of a gene
• Homozygous is when both inherited alleles are the same
• Heterozygous is when the all is different example, one is recessive and one is dominant
• Genotype is the set of individual collection of genes
• Phenotype what the person looks like a.k.a. physical characteristics
• mRNA strand is then used to make proteins by translation. mRNAleaves the nucleus, mRNA joins to ribosomes, tRNA joined to mRNA
• genes code for protein as a sequence of three base in a gene form a triplet. Each triplet code for an amino acid. The order of amino acid determines the structure and function of proteins formed.
• How can plasmid be gentically modify a bacteria ce to contain a human gene?

  remove the human gene. The plasmid is cut using restrictive enzyme and the gene is added to plasmid
• Advantage and disadvantage of the use of biofuel?


  + reduces co2 when growing

  + it’s is renewable

  • reduces food production
  • reduces biodiversity
• What are the risk of selective breeding?

  reduces Gene pool

  inbreeding- prone to disease or inherited defects

  less variation within a population
• Why are plants bred for ?

  better quality of food

  coping with environmental conditions- diseases

  increases yield

  Fast growth
• advantage of GM ‘gold rice’?

  produces vitamin A which helps to see
• Disadvantage of GM ’gold rice‘?

  expensive

  some people say it’s bad for health
• Explain why mitochondrial DNA is used rather than nuclear DNA?

  higher abundance

  high mutation rate