Biology paper 1

• Plant and animal cells are what type of cell

  Eukaryotic
• What type of cell is bacterial cells

  Prokaryotic
• What do Eukaryotic cells have?

  Cell membrane, cytoplasm, nucleus
• What do prokaryotic cells have in them?

  Cytoplasm, cell membrane, (no nucleus)
• Function of nucleus 


  Controls the cell
• Function of cytoplasm?


  Where chemical reactions happen
• Function of a cell membrane?


  Controls what goes in and out of the cell
• Function of mitochondria?


  Releases energy via respiration
• Function of ribosomes?


  Protein synthesis
• Function of chloroplast?


  Produces energy via photosynthesis
• Function of a vacuole?

  Contains cell sap
• Function of cell wall?


  Strengthens the cell
• Why are electron microscopes better?

  Increased understanding of sub-celluar structures.

  Higher magnification and resolving power.

  Can study cells in finer detail.
• What are chromosomes?


  Contains DNA molecules.

  Each chromosomes carries a large number of genes.

  In body cells chromosomes are usually found in pairs.
• Describe the steps of the cell cycle

  increases in size, copies its DNA, prepares to divide, and divides (mitosis)
• What are stem cells?

  A stem cell is an undifferentiated cell.
• Stem cells can be used for?


  Cloning
• Stem cells from human embryos can be cloned and made to differentiate into most different human cells.

  Stem cells from adult bone marrow can form many types of cells including blood cells.
• What is the function of meristem tissue in plants?


  Can differentiate into any type of plant cell, throughout the life of the plant.
• Treatment using stem cells can help treat?

  Diabetes

  Paralysis
• What occurs during therapeutic cloning?


  An embryo is produced with the same gene as the patient.

  Stem cells from the embryo are not rejected by the patients body so they may be used for medical treatment.
• What are the risks of using stem cells?

  Transfer of viral infection.

  Some people have ethical or religious objections.
• Stem cells from meristems can be used to?

  Produce clones of plants quickly and economically.
• Reasons to clone?


  Rare species can be cloned to protect extinction.

  Clone plants with special features such as disease resistance, then can produce large number of identical plants for farmers.
• Diffusion?


  The movement of particles from a high to low concentration.
• What is osmosis?


  The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
• What is Active transport?


  Movement of substances from a more dilute solution to a more concentrated solution.
• What are cells?


  The basic building blocks of all living organisms.
• What are tissues?


  A group of cells with a similar structure and function.
• What are organs?


  Structures in the body that perform specific functions.
• What is an organ system?


  A group of organs which work together to form organisms.
• Where is bile made?


  The liver.
• Where is bile stored?


  Gallbladder.
• What does bile do?

  Is is an alkaline to neutralise hydrochloric acid from the stomach.
• What are enzymes?


  A biological catalyst.
• What is the lock and key method?

  Enzymes are folded into complex shapes that allow smaller molecules to fit into them.

  The place where the molecules fit is called the active site.

  The shape of the active site matches the shape of its substrate molecules.
• What does high temperature do to an enzyme?

  Changes the shape.
• What happens if the temperature is too high on the enzymes?

  It denatures.
• Different enzymes work best at different pH values. This is called optimum pH.
• What does amylase do?

  Breaks down carbohydrates into simple sugars.