Cell division and stem cells

• What is the process by which cells divide for growth and repair?

  Mitosis
• What type of cell division produces gametes for sexual reproduction?

  Meiosis
• What do stem cells do during the development of organisms?

  They differentiate into specialised cells
• What is the structure made of DNA that codes for all the characteristics of an organism?

  Chromosome
• How many chromosomes does each human body cell contain?

  46 chromosomes
• What is the basic unit of genetic material inherited from our parents?

  Gene
• What is the role of a gene in a cell?

  It controls part of a cell's chemistry, particularly protein production
• What is the outcome of mitosis in terms of daughter cells?

  Two daughter cells identical to the parent cell
• What happens to the number of chromosomes during mitosis?

  The number of chromosomes remains constant
• What is cancer in terms of cell division?

  A disease caused by normal cells growing and dividing uncontrollably
• What is a tumour?

  A lump of cells formed as a result of uncontrolled cell division
• What are carcinogens?

  Chemicals or agents that cause cancer
• How do carcinogens cause cancer?

  By damaging DNA, leading to mutations
• Why are older individuals more likely to develop cancer?

  Because several mutations are required for cancer to develop
• What is a risk factor?

  Something that increases the likelihood of developing a disease
• What lifestyle factor is linked with an increased risk of lung cancer?

  Chemical carcinogens in cigarette smoke
• How does a poor diet contribute to cancer risk?

  By increasing fat and salt intake and consuming certain foods
• What is the link between alcohol intake and cancer?

  Alcohol intake is linked with certain cancers
• What industrial factor increases cancer risk?

  Exposure to chemical carcinogens
• What are the key processes of cell division?

  • Mitosis: for growth and repair
  • Meiosis: to produce gametes for sexual reproduction
  • Stem cells differentiate into specialised cells
• What is ionising radiation?

  Radiation that can remove electrons from atoms or molecules
• What environmental factor increases cancer risk?

  Exposure to ionising radiation
• What are the main characteristics of cancer cells compared to normal cells?

  • Cancer cells grow and divide uncontrollably
  • They produce new cells even when not needed
  • They form tumours
• What type of radiation is associated with skin cancer?

  Ultraviolet radiation
• What are the main risk factors for developing cancer?

  • Lifestyle factors (e.g., smoking, alcohol)
  • Environmental factors (e.g., ionising radiation)
  • Genetic factors
• What type of cell division do cells undergo for growth and repair?

  Mitosis
• What type of cell division produces gametes for sexual reproduction?

  Meiosis
• What do stem cells differentiate into during the development of organisms?

  Specialised cells
• What is the process of sexual reproduction?

  • Formation of a new organism
  • Combining genetic material from two organisms
  • Involves male and female gametes
• What is a gamete in males and females?

  Sperm in males and ova/eggs in females
• What is a zygote?

  A fertilised egg cell
• How many chromosomes does each human gamete contain?

  23 chromosomes
• What is the term for the fusion of gametes?

  Fertilisation
• What happens when male and female gametes fuse?

  They form a zygote with 46 chromosomes
• What type of cell division forms gametes?

  Meiosis
• How many gametes are produced at the end of meiosis?

  Four gametes
• What type of cells are produced by meiosis?

  Haploid cells
• What is a key feature of gametes produced by meiosis?

  They are genetically different from each other
• Compare mitosis and meiosis in terms of daughter cells produced.

  Mitosis:

  • Produces 2 genetically identical daughter cells
  • Full set of chromosomes

  
  

  Meiosis:

  • Produces 4 genetically varied daughter cells
  • Half set of chromosomes
• What are the main purposes of mitosis and meiosis?

  Mitosis:

  • Growth
  • Repair of damaged cells

  
  

  Meiosis:

  • Formation of gametes for sexual reproduction