Unit 2 Multicellular Organisms

    Cards (102)

    • What is mitosis?
      Mitosis is the process of cell division.
    • Why is mitosis important?
      It provides new cells for growth and repair and maintains the diploid chromosome complement.
    • How many chromosomes are present in a human cell?
      There are 46 chromosomes in a human cell.
    • How many chromosomes will each daughter cell have after mitosis?
      Each daughter cell will have 46 chromosomes.
    • What are the main stages of mitosis?
      1. Chromosomes replicate and become visible as two chromatids.
      2. The nucleus breaks down.
      3. Chromosomes line up along the equator, and spindle fibres attach.
      4. Spindle fibres pull chromatids apart to opposite ends of the cell.
      5. Separated chromatids become chromosomes, and nuclear membranes form.
      6. The cytoplasm splits, resulting in two daughter cells.
    • What are stem cells in animals?
      Stem cells are unspecialised cells that can divide to make more stem cells.
    • What potential do stem cells have?
      They have the potential to become different types of cells, such as skin or muscle cells.
    • Where can stem cells be obtained from?
      Stem cells can be obtained from the embryo at a very early stage.
    • What is specialisation in the context of stem cells?
      Specialisation is when a stem cell becomes a specific type of cell.
    • How are cells organized in multicellular organisms?
      • Cells make up tissues, which are groups of cells carrying out similar functions.
      • Different tissues come together to form organs.
      • Organs work together to form systems.
    • What is the nervous system made up of?
      The nervous system is made up of the brain, spinal cord, and nerves.
    • What does the central nervous system (CNS) consist of?
      The CNS consists of the brain and spinal cord.
    • What are the functions of the different regions of the brain?
      • Cerebrum: personality, logic, intelligence, memories
      • Cerebellum: balance and coordination
      • Medulla: breathing and heart rate
    • What are the three types of nerve cells in the nervous system?
      The three types of nerve cells are sensory, inter, and motor neurons.
    • How do sensory neurons function in the nervous system?
      Sensory neurons pass information to inter neurons in the CNS.
    • What role do inter neurons play in the nervous system?
      Inter neurons process information in the CNS and pass it to motor neurons.
    • What do motor neurons do in the nervous system?
      Motor neurons enable a response to occur at an effector, such as a muscle or gland.
    • How do messages travel along neurons?
      Messages travel along neurons as electrical impulses.
    • What are neurotransmitters?
      Neurotransmitters are chemicals that transfer messages between neurons at synapses.
    • What is the arrangement of neurons called?
      The arrangement of neurons is called a reflex arc.
    • What are reflexes?
      Reflexes are rapid, automatic responses that protect the body from harm.
    • Can you give examples of reflex actions?
      Examples of reflex actions include sneezing, coughing, and blinking.
    • What do endocrine glands release?
      Endocrine glands release hormones into the bloodstream.
    • What are hormones?
      Hormones are chemical messengers.
    • What is a target tissue?
      A target tissue has cells with complementary receptor proteins for specific hormones.
    • Which hormones regulate blood glucose concentration?
      Insulin and glucagon regulate blood glucose concentration.
    • Where are insulin and glucagon released from?
      Both hormones are released from the pancreas.
    • When is insulin released?
      Insulin is released when the blood glucose concentration rises.
    • What does insulin instruct the liver to do?
      Insulin instructs the liver to take up excess glucose and store it as glycogen.
    • When is glucagon released?
      Glucagon is released when the blood glucose concentration falls.
    • What does glucagon instruct the liver to do?
      Glucagon instructs the liver to break glycogen down into glucose and put it back into the blood.
    • What are the lungs primarily used for?
      Gas exchange
    • What do alveoli provide for gas exchange?
      A large surface area
    • How do oxygen and carbon dioxide move in the lungs?
      Through thin alveolar walls
    • Where does oxygen move from and to?
      From lungs to blood
    • Where does carbon dioxide move from and to?
      From blood to lungs
    • What is the role of the small intestine?
      Absorbing nutrients from food
    • What structures in the small intestine absorb nutrients?
      Villi
    • What do the thin-walled villi provide?
      A large surface area
    • What do villi contain to absorb nutrients?
      A network of capillaries and lacteals