Inheritance, variance and evolution

• Polydactyly is a dominant disorder.
• Cystic fibrosis is a recessive disorder.
• During genetic engineering, the human insulin gene is insured into the loop of DNA called a plasmid.
• In genetic engineering, at what point is the gene transferred to the cell of an organism?


  Early stages of development
• What name is given to the loops of DNA in the cytoplasm of bacteria?

  Plasmids.
• Some mutations in genes can lead to changes in the phenotype of an organism. What are these known as?


  Variation
• Fossil footprints form most easily in damp sediments.
• Heterozygous is when an individual has two different alleles if a gene.
• What is the allele that is expressed in a heterozygous individual called?


  Dominant
• Which domain from the three-domain system includes primitive bacteria that usually live in extreme environments?

  Archaea
• The genetic makeup of an organism is called the genotype.
• The international system used to name species is called binomial nomenclature.
• An advantage of asexual reproduction is that it produces offspring quickly.
• Male and female gametes have 23 chromosomes.
• Reproduction without the need for sex cells is called asexual reproduction.
• Apart from being quick and easy, another advantage of taking cuttings over other cloning techniques is that it is less expensive.
• Some early fossils have been destroyed by volcanic activity.
• An enucleated cell is one that's had it's nucleus removed.
• A diploid nucleus is used in adult cell cloning
• An organism that has DNA form another species is called transgenic
• Micropropagation is using tissue cultures to clone a plant
• How many genes linked to diseases has the HGP found?

  2,000
• Geographical isolation is when a species is separated
• Ethene gas is used to ripen fruit and vegetables
• Base A is complementary to Base T
• Base C is complementary to Base G
• Malarial parasites reproduce asexually in humans, but sexually in mosquitos.
• Many fungi reproduce asexually by spores but also sexually to give variation.
• Plants produce seeds sexually, but also reproduce asexually by runners or bulb division.
• DNA is contained in chromosomes.
• The human genome can:

  • Search for genes linked to different types of disease
  • Understanding and treating inherited disorders
  • Tracing human migration patterns
• Proteins are synthesised on ribosomes
• Gregor Mendel carried out experiments on pea plants to discover inheritance
• Gametes are sex cells
• Meiosis:

  1. Chromosomes in diploid cell (23 pairs) copied
  2. Similar chromosomes pair up and genes are swapped between them
  3. Cell divides to produce two diploid cells
  4. These divide again to produce 4 haploid cells (gametes)
• An advantage of sexual reproduction is that offspring can become better adapted to environment.
• An advantage of asexual reproduction is that it only requires one parent.
• Genome - entire genetic code in an organism
• Genotype - an organisms specific genetic code
• Phenotype - how an organism's genetic code is expressed in physical characteristics