Paper 1

• What is the main content of the nucleus in a cell?

  The nucleus contains genetic information in the form of chromosomes.
• What do chromosomes contain?

  Chromosomes contain coils of DNA.
• What is a gene?

  A gene is a short section of DNA that codes for a protein.
• How many pairs of chromosomes are found in each human cell?

  There are 23 pairs of chromosomes in each human cell.
• What is the total number of chromosomes in each human cell?

  There are 46 chromosomes in total in each human cell.
• How many chromosomes are present in human gametes?

  There are 23 chromosomes in total in each gamete cell.
• What is the diploid number of chromosomes in humans?

  The diploid number of chromosomes in humans is 46.
• What is the haploid number of chromosomes in humans?

  The haploid number of chromosomes in humans is 23.
• What is the cell cycle?

  The cell cycle is a series of steps that the cell undergoes to divide.
• What is mitosis?

  Mitosis is the stage in the cell cycle when the cell divides.
• What happens during interphase?

  During interphase, the cell grows, organelles increase, proteins are synthesized, DNA is replicated, and energy stores are increased.
• What occurs during the mitosis stage of the cell cycle?

  During mitosis, chromosomes line up at the equator and are pulled to either side of the cell.
• What is cytokinesis?

  Cytokinesis is the stage where two identical daughter cells form when the cytoplasm and cell membranes divide.
• Why is mitosis important in multicellular organisms?

  Mitosis is important for growth, development, and replacing damaged cells.
• How many daughter cells are produced by mitosis?

  Mitosis produces 2 daughter cells.
• What type of cells do daughter cells produced by mitosis have?

  Daughter cells produced by mitosis have identical sets of chromosomes to the parent cell.
• What is the genetic relationship between daughter cells and parent cells in mitosis?

  Mitosis produces genetically identical diploid daughter cells.
• What happens to cells after they differentiate in animals?

  Most cells differentiate at an early stage and then lose the ability to differentiate further.
• How do specialized cells in animals reproduce?

  Most specialized cells can replicate themselves by undergoing mitosis.
• How does growth occur in animals?

  Growth in animals occurs via cell division and differentiation.
• What is the role of adult stem cells in animals?

  Adult stem cells can replace specialized cells that cannot divide, like red blood cells.
• How does growth occur in plants?

  Growth in plants occurs by cell division, differentiation, and elongation.
• What is elongation in plant growth?

  Elongation is when plant cells grow longer in a specific direction by absorbing water into their vacuoles.
• What controls the elongation process in plants?

  Elongation is controlled by substances called auxins.
• How do plant cells differentiate?

  Plant cells differentiate when they reach their final position and can re-differentiate if moved.
• What causes cancer in cells?

  Cancer occurs due to small changes in cells that lead to uncontrolled cell division.
• What is a tumour?

  A tumour is a group of cells resulting from uncontrolled cell division.
• Why is it important to monitor growth in organisms?

  Monitoring growth helps check the progress of crops or whether a child is growing normally.
• What are percentiles charts used for?

  Percentiles charts are used to measure the growth rate of an organism.
• How can the growth of babies be measured?

  The growth of babies can be measured using mass, length, or head circumference.
• What does it mean for a baby to be at the 50th percentile for mass?

  A baby at the 50th percentile for mass is heavier than 50% of babies.
• What does it mean for a baby to be at the 25th percentile for mass?

  A baby at the 25th percentile for mass is heavier than 75% of babies.
• What does it mean for a baby to be at the 75th percentile for mass?

  A baby at the 75th percentile for mass is heavier than 25% of babies.
• What can indicate a health problem in babies regarding percentiles?

  Being in a high percentile (e.g., 90th percentile or higher) can indicate a health problem.
• What is a stem cell?

  A stem cell is an undifferentiated cell that can undergo division to produce more similar cells.
• What are embryonic stem cells?

  Embryonic stem cells form when an egg and sperm cell fuse to form a zygote.
• What can embryonic stem cells differentiate into?

  Embryonic stem cells can differentiate into any type of cell in the body.
• How can scientists use embryonic stem cells?

  Scientists can clone embryonic stem cells and direct them to differentiate into almost any cell type.
• What potential medical uses do embryonic stem cells have?

  Embryonic stem cells could potentially replace insulin-producing cells or create new neural cells for diseases.
• What are adult stem cells and where are they found?

  Adult stem cells are found in bone marrow and can form many types of cells, including blood cells.