Combined paper 2

• What is a synapse?

  The gap between neurons
• How are hormones transported around the body?

  Through the bloodstream
• Describe the steps in meiosis

  • Genetic information is copied, cell divides twice to form four gametes, each with a single set of chromosomes. All gametes are genetically different
• What is cystic fibrosis?

  • A disorder of the cell membrance

  • caused by a recessive allele
• Define fossil

  Remains of an organism found in rocks
• Who developed the “3 domain system”?

  Carl Woese
• Define biodiversity

  The variety of all the different species of organisms on earth, or within an ecosystem
• How is the structure of a neurone adapted to its function?

  Very long to transmit impulses over long distances and insulated.
• How is type 2 diabetes treated?

  Must be controlled through a carbohydrate controlled diet, and excercise
• Define asexual reproduction

  • Involves only one parent

  • No fusion of gametes

  • Only mitosis involved
• What is polydactyly?

  A dominant condition involving the growth of extra digits (fingers or toes)
• State 2 sources of evidence for evolution

  • Fossil records

  • Antibiotic resistance in bacteria
• What improvements led to the new model of classification?

  Better microscopes and better understanding of biochemical processes
• Describe the main processes in the carbon cycle

  • Photosynthesis produces glucose, respiration converts glucose to carbon dioxide

  • Feeding passes food through the ecosystem

  • Decay

  • Combustion
• Sequence the pathway of a signal through the reflex arc

  Stimulus -> Receptor -> Sensory neurone -> Relay neurone -> Motor neurone -> effector -> Response
• How is type 1 diabetes treated?

  Can be controlled in insulin injections
• Name the gametes in plants

  Pollen, ovum (egg)
• Define phenotype

  The characteristics that are expressed through the genes
• Sequence the steps in genetic engineering

  • Enzymes are used to isolate the gene

  • Gene is inserted into a vector (plasmid or virus).

  • Vector is used to insert gene into required cells.

  • Genes are transferred at an early stage of development
• State the 2 parts of the binomial system

  • Species

  • Genus
• Describe the relationship between predators and prey in a stable community

  The numbers of predators and prey rise and fall in cycles -> predators lagging behind the prey
• All control systems include what 3 parts?

  Receptors, coordinator, effector
• Describe the difference between type 1 and type 2 diabetes

  Type 1: pancreas fails to produce insulin

  Type 2: body doesn’t respond to insulin produced
• Name the gametes in animals

  Sperm and Egg
• Define Genotype

  The combination of alleles present in the genome
• State 2 reasons why people are opposed to genetic modification

  • Due to the potential effects on wild flowers and insects

  • effects on human health have not been fully explored
• State the 7 levels of organisation.

  • Kingdom

  • Phylum

  • Class

  • Order

  • Family

  • Genus

  • Species
• Define the term consumer

  An organism that eats other orgamisms
• List 3 factors that are controlled by homeostasis.

  • Body temperature

  • Blood glucose

  • Water levels
• Name the molecule that is used as a store of glucose.

  Glycogen
• Define sexual reproduction


  The fusion of male and female gametes
• Define heterozygous

  Alleles are different
• Give 2 examples of how plants have been genetically engineered.

  • Resistance to attack by insects

  • Increased yields
• Who developed the traditional method of classification of living things

  Carl Linnaeus
• Why are plants known as producers?

  Because they synthesise molecules such as glucose
• What is the role of homeostasis

  Regulation of internal conditions to maintain optimal conditions
• Name the hormone produced to raise blood glucose

  Glucagon
• Describe the role of thyroxine


  • Stimulates the basal metabolic rate

  • Plays an important role in growth and development
• Define homozygous


  Both alleles are the same
• What does genetic engineering involve?

  • Genes are ‘cut out’ using enzymes and transferred to other organisms using vector (usually a plasmid or virus)