B6- Inheritance, Variation and Evolution

• What is meiosis?

  Formation of four non-identical cells
• What is mitosis?

  Formation of two identical cells
• What does sexual reproduction involve?

  Joining of male and female gametes
• What are the gametes in animals?

  Sperm and egg cells
• How are gametes formed?

  By meiosis
• How many chromosomes does a normal cell have?

  46 chromosomes
• How many chromosomes does each gamete have?

  23 chromosomes
• What happens during fertilization?

  Gametes fuse to form a cell with 46 chromosomes
• What is asexual reproduction?

  Involves one parent without gametes
• What process forms identical cells in asexual reproduction?

  Mitosis
• What do clones refer to in asexual reproduction?

  Genetically identical organisms
• Name an organism that reproduces asexually.

  Bacteria
• What is the advantage of sexual reproduction?

  Produces variation in offspring
• What is a survival advantage?

  Characteristic allowing survival in changing environments
• What is selective breeding?

  Breeding organisms for desirable traits
• How do malarial parasites reproduce?

  Sexually in mosquitoes, asexually in humans
• How do some fungi reproduce?

  Both sexually and asexually through spores
• What is pollination in plants?

  Pollen reaching egg cells in flowers
• How do strawberry plants reproduce asexually?

  By producing runners
• What is the structure of DNA?

  Polymer made of two strands in a double helix
• What are chromosomes made of?

  Long strands of DNA
• What is a gene?

  A section of DNA coding for a protein
• What is the human genome?

  All genes coding for proteins in humans
• What is the role of DNA in protein synthesis?

  Contains the genetic code for proteins
• What is the process of protein synthesis?

  Producing proteins from DNA instructions
• What is mRNA?

  A template of the original DNA strand
• What happens at the ribosomes during protein synthesis?

  mRNA bases are read to code for amino acids
• What determines the type of protein produced?

  The order of amino acids in the chain
• What are mutations?

  Changes in the sequences of bases in DNA
• What is a dominant allele?

  Only one copy needed for expression
• What is a recessive allele?

  Two copies needed for expression
• What is homozygous?

  Both inherited alleles are the same
• What is heterozygous?

  One dominant and one recessive allele
• What is a genotype?

  Combination of alleles an individual has
• What is a phenotype?

  Physical characteristics observed in an individual
• What do family trees show?

  Inheritance of phenotypes over generations
• What is a single gene cross?

  Probability of offspring genotypes and phenotypes
• What is a Punnett square used for?

  To predict offspring genotypes and phenotypes
• What do uppercase letters represent in genetics?

  Dominant characteristics
• What do lowercase letters represent in genetics?

  Recessive characteristics