Biology Revision

Biology Revision

Plant Biology

Transport

Xylem Tissue

  • 1 way transport system
  • Transports water and nutrients from the roots to the shoots

Phloem Tissue

  • 2 way transport system
  • Transports sugary cell sap throughout the plant

Components

Palisade Cells
Palisade cells are the cells containing the most chloroplasts, which contains chlorophyll for photosynthesis. It absorbs the most light in the whole plant.

Spongy mesophyll
The function of the spongy mesophyll is for the occurrence of gas exchange between CO2, a useful gas, and O2, a wasted gas, within the plant.

Stomata / Guard Cells
Stomata: The stomata are the holes which allow for the release of gases wasted in the gas exchange process. Stomata are tiny holes which intake carbon dioxide and get rid of waste oxygen.


Guard cells: Surrounding each stoma, they help to regulate the transpiration (the process of water movement through the plant)

Bioenergetics

Photosynthesis equation
6CO2 + 6H2O + light energy → C6H12O6 + 6O2.
Carbon Dioxide + Water + Light energy → Glucose + Oxygen

Respiration Equation
C6H12O6 + 6O2 → 6CO2 + 6H2O
Glucose + Oxygen → Carbon Dioxide + Water

What is photosynthesis?
Photosynthesis is a plant's way of making its own food. Using chlorophyll, it takes carbon dioxide, light energy and water and turns it into glucose and oxygen by turning the light into its own food.

Cell Biology

Components and Functions - Plant
Nucleus - Contains our DNA and genetic material
Ribosomes - synthesise protein
Mitochondria - conducts respiration for energy
Cytoplasm - chemical reactions
Cell membrane - controls what enters and exits the cell
Cell wall - keeps the rigid structure of the cell
Chloroplasts - contains chlorophyll for the conduction of photosynthesis
Vacuole - contains sticky cell sap which helps with turgidity

Components and Functions - Animal


Nucleus - Contains our DNA and genetic material
Ribosomes - synthesise protein
Mitochondria - conducts respiration for energy
Cytoplasm - chemical reactions
Cell membrane - controls what enters and exits the cell

Diseases

Virus & Bacteria


Virus

  • Chicken pox
  • Influenza (flu)
  • Herpes
  • HIV / AIDS

Bacteria

  • Salmonella
  • Food poisoning
  • Tubercolosis

Structure of a virus

  • Shaped as a hexagon
  • contains viral genome (RNA)
  • strand of genes, not contained in a nucleus - prokaryotic
  • protein coating - can change when needed to halt the process of antivirals

Viruses

  • Smallest type of microbe
  • Recognised as non-living
  • Invade host cells and use cell machinery to make copies of themselves
  • These copies cause cells to burst, releasing virus particles to new cells

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