Topic 6 - Inheritance, Variation and Evolution

• What does DNA stand for?

  deoxyribonucleic acid
• What structure does DNA have

  double helix, made of 2 strands
• Where is DNA found in the human cell?

  chromosomes in the nucleus
• How many chromosomes are there?

  46 (23 pairs)
• What is the 23rd pair of chromosomes role

  sex chromosomes
• What chromosomes do women have?

  XX
• What chromosomes do men have?

  XY
• What is a gene?


  segment of DNA that codes for a protein
• How can DNA code for proteins?

  by coding for the sequence in which amino acids are joined together
• What does the term genome mean?

  The entire set of genetic material in an organism
• What are alleles?


  Different forms of a gene
• What does genotype mean?


  genetic make up of an organism
• What does phenotype mean?


  Physical appearance of a genetic trait
• What is a dominant allele?

  A form of a gene that is fully expressed, even when two different alleles are present
• What is a recessive allele?


  An allele that is masked when a dominant allele is present.
• When is a recessive allele expressed?


  When there are two recessive alleles present
• What does homozygous mean?


  two of the same alleles
• What does heterozygous mean?

  two different alleles
• How do animals reproduce?

  sexual reproduction
• What process is used to create gametes


  meiosis
• What is the fusion of male and female gametes

  fertilization
• What is a haploid cell?


  a cell that contains one set of chromosomes (23)
• What is a diploid cell?

  A cell with two sets of chromosomes (46)
• How many parents are involved in asexual reproduction


  One
• What is the result of asexual reproduction?

  genetically identical offspring
• what process is used in asexual reproduction

  mitosis
• What process is used in sexual reproduction


  meiosis
• What process do bacteria use in asexual reproduction


  Binary fission
• During meiosis how many times does the cell divide?

  twice
• How many cells are produced via meiosis?

  4
• How would you describe the genotype AA

  homozygous dominant
• How would you describe the genotype Hh

  heterozygous
• How would you describe the genotype dd

  homozygous recessive
• What is a punnet square?


  a diagram that is used to predict the outcome of generation

  
• What condition is cystic fibrosis? (dominant or recessive)

  recessive
• What genotype would result in an individual having cystic fibrosis?

  Homozygous recessive
• What does the term carrier mean?

  refers to a heterozygous individual that has the allele for the recessive trait but doesn't display it.
• What is polydactyly?


  A genetic disorder where a baby's born with extra fingers or toes.
• What does an inherited disease mean?

  It can be inherited from an individual's parents
• What allele is polydactyl caused by?


  dominant