cell biology

• name key parts of the animal cell

  nucleus, cytoplasm, cell membrane, ribosomes, mitochondria
• name key parts of an animal cell

  (same as animal cell)+ vacuole, cell wall and chloroplasts
• What are the differences between prokaryotic and eukaryotic cells?

  Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and membrane-bound organelles. prokaryotic is also smaller and contains plasmids.
• What is a plasmid?

  A small, circular piece of DNA that is separate from the chromosomal DNA and can replicate independently.
• What are cell walls made from?

  Cellulose fibres
• How is a sperm cell adapted to its function?

  Streamlined shape, tail for movement, lots of mitochondria to release energy, acrosome that release enzymes to digest the cell membrane
• How is a nerve cell adapted to its function?

  Long, branching extensions called dendrites receive signals, while long axons transmit signals over long distances. The axon is insulated by a myelin sheath, which speeds up signal transmission. At the end of the axon, neurotransmitters are released to transmit signals to other cells.
• How is a muscle cell adapted to its function?

  Contains filaments of protein that slide over each other to cause a muscle contraction. Contains many well-developed mitochondria to provide energy for muscular contraction.
• How is a root hair cell adapted to its function?

  Large surface area- increases rate of absorption. Lots of mitochondria. Adapted to take in mineral-ions.
• What is cell differentiation?

  Cell differentiation is the process by which cells become specialized in structure and function.
• What's the difference between magnification and resolution?

  Magnification refers to the increase in the apparent size of an object, while resolution refers to the ability to distinguish between two separate points or objects.
• Why is an electron microscope able to see smaller details than a light microscope?

  Wavelength.- electrons have a shorter wavelength than visible light.
• What does a cell nucleus contain?

  Chromosomes made of DNA
• What are the stages of cell division in the cell cycle?

  The cell undergoes a type of cell division called mitosis. The cell begins to divide, DNA replicates to form 2 copies of each chromosome, the nuclear membrane breaks down, chromosomes line up across the center of the cell, one set of chromosomes is pulled to each end of the cell, the nucleus divides, cytoplasm and cell membranes divide to form 2 identical cells.
• What is a stem cell?

  Undifferentiated cell.
• Where can human stem cells be harvested from?

  Embryos, umbilical cord blood, and adult tissues such as bone marrow and adipose tissue.
• What is meristem tissue in plants?

  Undifferentiated plant tissue responsible for growth and development.
• Which conditions might stem cell treatment be able to help?

  Parkinson's disease, spinal cord injuries, heart disease, diabetes, and certain types of cancer.
• What are some common objections to stem cell use in medical treatment?

  Ethical concerns, religious objections, and destroying potential human life.
• What is diffusion?

  Diffusion is the movement of particles from an area of high concentration to an area of low concentration through a partially permeable membrane, down the concentration gradient.
• What substances move in and out of cells by diffusion?

  Small molecules, such as oxygen and carbon dioxide, move in and out of cells by diffusion.
• How does the concentration gradient affect the rate of diffusion?

  The concentration gradient affects the rate of diffusion by influencing the direction and speed of particle movement from an area of high concentration to an area of low concentration. Greater concentration means faster diffusion.
• How does temperature affect rate of diffusion?

  Temperature increases the kinetic energy of particles, leading to faster movement and increased rate of diffusion.
• How does surface area affect rate of diffusion?

  It increases the rate at which particles can move across the membrane.
• How are alveoli in the lungs adapted to maximize the rate of diffusion?

  Thin walls (one cell thick), large surface area, good supply of blood, moist walls.
• What is osmosis?

  Osmosis is the movement of water molecules from an area of lower solute concentration to an area of higher solute concentration across a partially permeable membrane.
• What is active transport?

  Active transport is the movement of molecules or ions across a cell membrane against their concentration gradient, requiring energy.
• Where does active transport occur in the human body?

  Internal lining of the small intestine- absorption of nutrients into the bloodstream.
• Which substances are moved by active transport in the body?

  Ions, glucose, amino acids, and some vitamins.
• Where does active transport occur in plants?

  Across the root so that plants take in ions from the soil.
• Which substances are moved by active transport in plants?

  Minerals and ions.