Cells and control

• What does the nucleus contain?

  Your genetic information
• What are chromosomes made of?

  Coils of DNA
• What is a gene?


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

  23 pairs
• How many total chromosomes are there in each human cell?

  46 chromosomes
• What is the chromosome count in gametes?

  23 chromosomes
• What is the diploid number of chromosomes in humans?

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

  23 chromosomes
• What are the stages of the cell cycle?

  1. Interphase: Cell growth, organelle increase, protein synthesis, DNA replication, energy store increase.

  2. Mitosis: Chromosomes line up at the equator and are pulled apart.

  3. Cytokinesis: Division of cytoplasm and cell membranes to form two identical daughter cells.
• What happens during interphase?

  The cell grows, organelles increase, proteins are synthesized, DNA is replicated, and energy stores increase
• What occurs during mitosis?

  The chromosomes line up at the equator and are pulled to either side of the cell
• What is formed during cytokinesis?

  Two identical daughter cells
• Why is mitosis important in multicellular organisms?

  It is important for growth, development, and replacing damaged cells
• How does asexual reproduction relate to mitosis?

  Asexual reproduction involves one organism replicating its own cells through mitosis
• How many daughter cells are produced by mitosis?

  2 daughter cells
• What type of daughter cells does mitosis produce?

  Genetically identical diploid daughter cells
• How does growth occur in animals?

  Through cell division and differentiation
• What happens to most specialized cells in animals after differentiation?

  They lose the ability to differentiate
• What is the role of adult stem cells in animals?

  They can form many types of cells, including blood cells
• How do plant cells grow longer?

  By absorbing water into their vacuoles
• What are auxins?


  Substances that control the elongation of plant cells
• How do plant cells differentiate?

  They differentiate when they reach their final position in the plant
• What causes cancer?


  Small changes in cells that lead to uncontrolled cell division
• What is a tumour?

  A group of cells resulting from uncontrolled cell division
• How is growth monitored using percentiles?

  • Percentiles charts measure growth rates.
  • For babies, growth can be measured using mass, length, or head circumference.
  • Percentiles indicate how a baby compares to others (e.g., 50th percentile means heavier than 50% of babies).
• What does being in the 75th percentile for mass indicate for a baby?

  The baby is heavier than 25% of babies
• What can a high percentile indicate for a baby?

  It can indicate a health problem
• What is a stem cell?

  An undifferentiated cell that can undergo division to produce more similar cells
• What are the types of stem cells?

  1. Embryonic stem cells: Can differentiate into any cell type.

  2. Adult stem cells: Found in bone marrow, can form many types of cells.

  3. Meristems in plants: Can differentiate into any type of plant throughout life.
• What is therapeutic cloning?

  Producing an embryo with the same genes as the patient to harvest stem cells
• What is the advantage of using stem cells from therapeutic cloning?

  They would not be rejected as they have the same genetic make-up as the individual
• What makes up the Central Nervous System (CNS)?

  The brain and spinal cord
• What functions does the CNS control?

  Consciousness, movements, thoughts, and emotions
• What are the main structures of the brain and their functions?

  • Cerebral hemispheres: Consciousness, memory, intelligence, visual and sensory processing.
  • Cerebellum: Controls fine muscle movements and coordination.
  • Medulla oblongata: Maintains basic autonomic bodily functions (breathing, digestion).
• What is the role of the cerebellum?

  It controls fine movements of muscles and coordination
• What is the function of the medulla oblongata?

  Maintaining basic autonomic bodily functions
• What are CT scans used for?

  To examine brain tissue for injury and disease
• How do CT scans generate images of the brain?

  By firing X-ray radiation at the brain from several angles
• What is the purpose of PET scans?

  To look inside the brain and examine brain function
• How do PET scans work?

  By detecting radioactive tracers in the brain