Bio yr9

• What is the purpose of cell division in mitosis

  sexual reproduction
• meiosis

  explain why chromosomes must duplicate before the cell divides

  • exact copies of each chromosome are made when chromosomes are duplicated (during interphase)
  • means when the cell divides, each new cell gain a full set during mitosis or half a set during mitosis or half a set during meiosis
• Describe how a full set of chromosomes is restored

  Gametes contain half a set of chromosomes, 2 gametes fuse together during fertilisation restoring the full set of chromosomes
• What is global warming and give one reason why it exists.

  the long-term heating of earths surface observed due to human activity (primarily fossil fuel burning)
• Sort the pics below

  stem cell , muscle cell , blood cell

  
• What do meristem cells do?

  clone plants ( can only clone plants)
• What and who do species depend on?

  Each other for food+shelter
• State an example of active transport

  Mineral ions from The soil into the root hair cell
• Name to ways a sperm cell is specialised

  • has a tail to swim around the egg
  • has enzymes to digest the membrane around the egg
• memorise the microscopy Practical 


  Here

  
• Deforestation increases the amount of co2 in the atmosphere.

  Give 2 reasons why

  • trees take in co2
  • less photosynthesis
• State the function of the nucleus 


  Controls and regulates the activities of the cell
• State the function of the cell wall (plant cell) 


  Protects a plant cell and supports structure
• state the function of the vacuole (plant cell)

  Stores harmful substances
• State the function of mitochondria 


  To generate the energy necessary to the power cells
• Function of the cell membrane 


  Controls what enters and exits the cell
• Function of the cytoplasm

  site of chemical reactions( where most chemical reactions take place) responsible for cell shape, material transport like genetic material and products for cellular respiration, and storage.
• Function of chloroplast ( plant cell)

  carries a process called photosynthesis
• Difference between animal Cells and plant cells

  Here

  
• give 3 negative effects of biodiversity

  • deforestation
  • climate change
  • pollution
• What is the site of aerobic respiration

  Mitochondria
• What do unicellular organisms have?

  very high surface area to volume ratio
• What do multicellular organisms have?

  Very low surface area to volume ratio
• What does mitosis produce?

  Cells with 46 chromosomes or 23 pairs
• State a measurable factor of biodiversity

  Genetic biodiversity
• What causes cancer?

  Genetic mutation
• What is worse malignant or benign

  Malignant cells are more likely to metastasise, or travel to other areas of malignant cells
• What do lots of different species mean?

  The ecosystem is less depend on 1 species
• give 2 reasons why it’s important to prevent organisms becoming extinct

  • organisms may produce substances useful to humans
  • duty to preserve for any future generations
• State an example of diffusion

  Oxygen diffuses from alveoli into the bloodstream
• What is biodiversity?

  The variety of all different species of organisms on earth
• 3 phases of the cell cycle

  1. Growth phase
  2. mitosis
  3. cell division
• What do adult stem cells do And where are they found?

  grows blood cells and found in the bone marrow (can on,y differentiate or undifferentiate into some blood cells
• Why are electron microscopes useful?


  They allow u to see and magnify organelles in more detail
• Why are large areas of these forests being destroyed?

  To provide land———- often used for rich fields/grazing ——— land is often used to grow crops which are then used to make biofuels
• what is process is where a cell can form another cell?

  Differentiation
• Difference between prokaryotic cells and eukaryotic cells

  Prokaryotic cells= unicellular, one membrane, bacterium

  eukaryotic cells= multicellular, 2 membranes, consists of many cells e.g plant+animal cells
• Where is mag adjusted?

  Fine focus wheel
• What is biodiversity important for?

  Ecosystems
• 4 ways humans can affect biodiversity….

  Habitat loss, resource exploitation and climate change