Inheritance, Variation, 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
• What are the gametes in flowering plants?

  Pollen and egg cells
• How are gametes formed?

  By meiosis, producing non-identical cells
• How many chromosomes does a normal cell have?

  46 chromosomes
• How many pairs of chromosomes are in a normal cell?

  23 pairs of chromosomes
• What happens during fertilization?

  Gametes fuse to form a cell with 46 chromosomes
• What is the result of genetic information mixing?

  Variation in the offspring
• What does asexual reproduction involve?

  One parent with no gametes joining
• How are identical cells formed in asexual reproduction?

  Through mitosis
• What is the outcome of asexual reproduction?

  Clones that are genetically identical
• Name an organism that reproduces asexually.

  Bacteria
• What is meiosis used for?

  To form gametes in reproductive organs
• How many copies of chromosomes do gametes have?

  One copy of each chromosome
• What happens to chromosomes during meiosis?

  They are shuffled, producing genetic variation
• What is the normal number of chromosomes in a fertilized cell?

  46 chromosomes
• What happens after fertilization?

  The cell divides by mitosis to form many copies
• What are the advantages of sexual reproduction?

  • Produces variation in offspring
  • Increases survival advantage in changing environments
  • Decreases extinction risk for species
• What are the advantages of asexual reproduction?

  • Only one parent needed
  • Faster reproduction in favorable conditions
  • Produces many identical offspring quickly
• How do malarial parasites reproduce in humans?

  Asexually in the liver and blood cells
• How do some fungi reproduce?

  By releasing spores that can be sexual or asexual
• How do strawberry plants reproduce asexually?

  By producing runners
• How do daffodils reproduce asexually?

  By growing from bulbs
• What is the structure of DNA?

  A 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 that codes for a protein
• What does the genome consist of?

  All genes coding for proteins in an organism
• How has studying the human genome helped medicine?

  Improved understanding of diseases and treatments
• What role do proteins play in the body?

  Carry out various functions based on shape
• What are enzymes?

  Biological catalysts that speed up reactions
• What happens when mutations occur in DNA?

  They change the sequences of bases
• How many pairs of chromosomes do humans have?

  23 pairs
• What do the chromosomes in each pair control?

  22 control characteristics
• What is unique about the 23rd pair of chromosomes?

  They carry sex determining genes
• How do Y chromosomes compare to X chromosomes?

  Y chromosomes are much smaller
• What are the two possible chromosomes in the 23rd pair?

  X and Y chromosomes
• What happens during meiosis regarding sex chromosomes?

  One sex chromosome goes into each gamete
• What chromosomes do females pass on in their eggs?

  Only X chromosomes