BIOLOGY: Inheritance, Variation and Evolution

• What are the two types of reproduction discussed?

  Sexual and asexual reproduction
• What is mitosis?

  A type of nuclear division for identical cells
• What is the purpose of mitosis?

  Growth, repair, replacement, and asexual reproduction
• What is meiosis?

  A type of nuclear division for different cells

  
• What does meiosis produce?

  Gametes that are genetically different
• What is sexual reproduction?

  Fusion of two gamete nuclei to form a zygote
• What are the gametes in animals?

  Sperm cells and egg cells
• What are the gametes in flowering plants?

  Pollen cells and egg cells
• What is fertilisation?

  Fusion of gamete nuclei from different parents
• How are gametes formed?

  Through meiosis
• What is asexual reproduction?

  Reproduction without sex cells or fertilisation
• What is the result of asexual reproduction?

  Genetically identical offspring (clones)
• What type of cell division is involved in asexual reproduction?

  Only mitosis
• What happens during meiosis in reproductive organs?

  Cells divide to form gametes

  
• Why must the number of chromosomes be halved in gametes?

  To prevent double chromosome number in zygote
• What is reduction division in meiosis?

  Halving chromosome number from diploid to haploid
• How many haploid cells does meiosis produce?

  Four haploid cells

  
• What occurs during the first division of meiosis?

  Chromosome pairs line up and are pulled apart

  
• What occurs during the second division of meiosis?

  Chromosomes line up and arms are pulled apart

  
• What is the importance of meiosis?

  Produces gametes and increases genetic variation
• How does meiosis increase genetic variation?

  By forming new combinations of chromosomes
• What happens at fertilisation?

  Gametes join to restore normal chromosome number
• What is a zygote?

  A fertilised egg cell
• What happens to the zygote after fertilisation?

  It divides by mitosis to form an embryo
• What is cell differentiation?

  Process of cells becoming specialised
• What is the genome?

  The entire set of genetic material
• What is DNA?

  A molecule containing instructions for growth
• What is the structure of DNA?

  Two strands forming a double helix

  
• Where is DNA contained?

  In structures called chromosomes

  
• What are genes?

  Short lengths of DNA that code for proteins
• What do genes control?

  Characteristics by coding for proteins
• What was the Human Genome Project?

  International effort to determine human DNA sequence
• Why is the Human Genome Project important?

  Improves understanding of diseases and treatments
• How does the human genome help study migration patterns?

  Shows small differences in genomes among populations
• What is monohybrid inheritance?

  Inheritance of characteristics controlled by a single gene
• What are alleles?

  Different versions of a gene
• What is the phenotype?

  Observable characteristics of an organism
• What is the genotype?

  The combination of alleles controlling characteristics
• What is a dominant allele?

  Only needs one parent to show in phenotype
• What is a recessive allele?

  Needs both parents to show in phenotype