Unit 1 Biology

• Describe the function of the cytoplasm


  Where all of the chemical reactions occur
• Describe the function of the vesicles


  Transport materials in the cell and out of the cell
• Describe the function of the nucleolus


  Produces ribosomes and RNA
• Describe the function of the cell wall


  Provides rigidity and protection to the cell
• Describe the function of the chloroplasts

  Site of photosynthesis as they contain chlorophyll
• Describe the function of the plasmodesmata


  A channel through the cell wall the allows transport of materials from one cell to another
• Describe the function of the amyoplasts


  Stores starch and converts starch back into glucose when the plant needs energy
• Describe the function of the vacuole


  Stores water and chemicals for cell use. Also maintains turgor of cell
• Describe the function of the tonoplasts


  Membrane the surrounds the vacuole. Protects the vacuole, isolates it from harmful substances and controls water flow in and out of the vacuole
• Why are gram positive bacteria more susceptible to antibiotics?


  Permeable cell wall whereas gram negative bacteria has a semi-permeable cell wall
• Describe the adaptations found in a palisade cell


  Closely packed together

  Chloroplasts

  Large vacuole
• Explain why the palisade cell has a large amount of chloroplasts

  To absorb lots of light for photosynthesis
• Explain why palisade cells are closely packed together

  To form a continuous layer in the leaf
• Explain why palisade cells have a large vacuole

  To maintain turgor (pushes against the cell wall to maintain rigid shape)
• Describe the adaptations of a root hair cell

  Root hair shape

  Large vacuole

  Thin cellulose walls
• Explain why root hair cells have an elongated section known as the root hair

  Increased surface area for maximum movement of water into the cell
• Explain why root hair cells have a large vacuole

  Contains cell sap with low water potential to encourage water into the cell
• Explain why root hair cells have thin cellulose walls

  Encourage movement of water and minerals into the cell
• Describe the adaptations of a sperm cell

  Undulipodium

  Lots of mitochondria

  Shaped head containing acrosome

  Haploid nucleus
• Explain why a sperm cell has an undulipodium

  To allow the sperm to move to the egg
• Explain why sperm cells contain large numbers of mitochondria

  To produce the large amounts of energy needed for movement
• Explain why sperm cells have a shaped head

  To push through the protective layer of the egg cell
• Explain why sperm cells contain acrosome in the head

  To digest the zona pellucida to allow entry into the egg cell
• Explain why sperm cells have a haploid nucleus

  Contains half the genetic material.
• Describe the adaptations of egg cells

  Contains a haploid nucleus

  Protective outer layer (zona pellucida)

  Corona radiata
• Explain why egg cells have a haploid nucleus

  Contains half the genetic material
• Explain why egg cells have a zona pellucida (protective layer)

  Protects the cell and only allows one sperm cell to enter.
• Explain why egg cells have a corona radiata (two or three layers attached to the zona pellucida)

  Contains all of the proteins needed to develop the fertilised cell
• Describe the adaptations of red blood cells

  No nucleus (mammals only)

  Biconcave shape

  Haemoglobin

  Flexible
• Explain why red blood cells don't contain a nucleus

  Allows for more oxygen to be carried in the cell
• Explain why red blood cells have a biconcave shape

  Increased surface area for gas exchange
• Explain why red blood cells contain haemoglobin

  To bind with the oxygen in order for it to be carried around the body
• Explain why red blood cells are flexible

  To fit through the tiny blood vessels such as capillaries
• Describe the adaptations of white blood cells

  Multi-lobed nucleus

  Enzymes found within the lysosomes
• Explain why white blood cells have a multi-lobed nucleus

  To enable the cell to squeeze through tiny gaps when travelling to the site of infection
• Explain why the lysosomes found within the cytoplasm of white blood cells contain enzymes

  To digest engulfed pathogens
• Name the 3 different types of epithelial tissue

  Squamous epithelial tissue

  Columnar epithelial tissue

  Endothelium tissue
• Describe squamous epithelial tissue

  A lining tissue that is only one cell thick. Made from squamous cells that form a smooth, flat layer.
• Where can squamous epithelial tissue be found?

  As it is a lining tissue it can be found inside alveoli
• How can squamous epithelial tissue be damaged by smoking?

  Inflammation and scarring of tissue

  Tissue gets thicker and produces more mucus

  Diffusion pathway is increased