Inheritance,Variation and Evolution

Cards (87)

  • Chromosomes are really long molecules of DNA
  • DNA is a polymer of nucleotides and forms a double helix shape
  • A gene is a code for a specific protein
  • Every organism has a genome which is the entire set of genetic material in an organism
  • Understanding the genome is important for inherited disease cause and treatments and population migrations
  • DNA is made up of nucleotides that consist of a base, sugar and phosphate
  • A and T and C and G pairings are called complimentary base pairings
  • Non-coding parts of DNA switch genes on and off
  • mRNA carries genetic code to the ribosomes to be translated into a protein
  • mRNA is made by copying DNA and acts as a messenger between DNA and ribosomes
  • Proteins have many functions including enzymes, hormones and structural proteins such as collogen
  • Mutations are random changes to the genetic code
  • Mutation chances are increased when exposed to certain types of radiation or substances
  • Most mutations have little effect on the gene
  • If there is a mutation within non-coding parts of genes, it can alter how genes are expressed
  • There are 3 different kinds of mutations: Insertions, Deletions and Substitutions
  • Insertion is where a new base has been inserted into the genetic code which changes the way the code is read
  • Bases code in threes
  • Deletion is where one or more bases are removed from the genetic code
  • Substitution is where a base has been swapped out for another
  • Induced mutations are caused by external factors such as radiation or chemicals
  • Spontaneous mutations happen when errors occur during DNA replication
  • Sexual Reproduction produces genetically different offspring
  • Each gamete in humans contains 23 chromosomes
  • Asexual Reproduction produces genetically identical cells
  • In Asexual Reproduction there is only 1 parent
  • Asexual Reproduction is the division of cells by mitosis
  • Gametes are produced by meiosis
  • The cell produced by a gamete fusion replicates itself
  • Sexual Reproduction increases variation in a population
  • Selective Breeding can be used to speed up natural selection
  • Asexual Reproduction only needs one parent therefore uses less energy, is faster and produces more offspring, which are all genetically identical
  • Some organisms can reproduce both sexually and asexually
  • Malaria parasites reproduce sexually in the mosquito and asexually inside the human host
  • Strawberry plants reproduce asexually through runners
  • Males have XY chromosomes and females have XX chromosomes
  • All eggs have one X chromosome
  • Genetic Diagrams show possible gamete and allele combinations
  • Some characteristics are controlled by a single gene
  • All genes exist in different versions called alleles