biology paper 2

• Another word for sex cells

  gametes
• state the 2 animal gametes

  sperm and egg cells
• state the 2 plant gametes

  pollen and egg cells
• number of parents involved in sexual reproduction

  2
• number of parents involved in asexual reproduction

  1
• describe the cells produced by mitosis

  2 genetically identical daughter cells ( diploid )
• describe cells produced by meiosis

  4 genetically different daughter cells ( haploid )
• what is mitosis used for 


  growth and repair
• what is meiosis used for

  production of gametes
• define a diploid cell

  cell with complete set of chromosomes
• define a haploid cell

  cell with half a set of chromosomes
• how many divisions occur in mitosis

  1
• how many divisions occur during meiosis

  2
• are haploid or diploid cells produced during mitosis

  diploid
• are haploid or diploid cells produced during meiosis

  haploid
• state the name of the genetic material found in nucleus of a cell

  DNA
• Describe the structure of a DNA

  polymer made of 2 strands forming a double helix
• state the name given to the structures where DNA is arranged and stored

  chromosomes
• state the name of a small section of DNA

  gene
• what does a gene code for

  sequence of amino acids which join to form a specific protein
• define the human genome

  all of the DNA found within a human
• 3 reasons for mapping human genome

  locating disease causing genes , treating inherited diseases , tracing human migration patterns
• Define Homozygous

  two of the same allele eg HH hh
• Define Heterozygous

  2 different alleles Hh
• Define dominant

  the allele thats always expressed
• Define recessive

  expressed only if 2 of this allele are present
• Define Genotype

  The 2 alleles present
• Define Phenotype

  the characteristic expressed e.g blue hair
• is cystic fibrosis caused by a dominant or recessive allele

  recessive
• is Huntingdon's caused by a dominant or recessive allele

  Dominant
• State the location and function of the cerebral cortex

  Outer section - perception , memory , language
• State the location and function of the cerebellum

  Base of the brain - balance & coordination of voluntary movements
• state the location and function of the medulla

  In the brain stem - controls involuntary functions e.g breathing
• why is it difficult to investigate brain function

  its very complex and very delicate
• state 3 ways of investigating the brain functions & regions

  brain damage patients , electrical stimulation of the brain , MRI scanning
• state 2 changes that can occur in the eye

  accommodation ( for focusing on near/far objects ) , adaptation to dim/bright light
• state 2 things the eye organ is sensitive to

  light intensity and colour ( wavelengths )
• state the name of the coloured part of the eye that expands in bright light and contracts in dim light

  iris
• state the name of the hole infront of out eye that allows light in

  pupil
• what happens to the size of the iris and pupil during bright light

  Pupil = small , Iris = big