Topic 1 - The nature and variety of living organisms

• Characteristics of living organisms

  • Movement
  • Respiration
  • Sensitivity (respond to surroundings)
  • Control internal conditions (homeostasis)
  • Nutrition
  • Excretion
  • Reproduce
  • Grow
• What does eukaryotic mean?

  Has membrane bound organelles e.g. animal cell has mitochondria, ribosomes and a nucleus
• What does prokaryotic mean?

  No membrane bound organelles - e.g. bacteria
• Both animal and plant cells contain:

  -Nucleus

  -Controls the activities of the cell

  -Cell membrane

  -Controls entry and exit of substances into the cell

  -Cytoplasm

  -Where chemical reactions take place

  -Mitochondria

  -Where aerobic respiration takes place -release energy

  -Ribosomes

  -Protein synthesis
• Organelles plant cell only:

  • Vacuole - Filled with cell sap contains dissolved sugars, and mineral ions
  • Chloroplasts
  • Carry out photosynthesis
  • Cell wall - Protects and supports the cell, made out of cellulose
• Give examples of different types of plant:


  • Flowering e.g. cereals (such as maize)
  • Herbaceous legume e.g. peas, beans
• Give examples of mammals and insects:

  • Mammals - humans
  • Insects - housefly, mosquito
• Bacterial cell organelles

  :

  A) Ribosome

  B) Cytoplasm

  C) cell membrane

  D) cell wall

  E) nucleoid (DNa)

  F) plasmid

  G) capsule

  
• Plant cell organelles

  :

  A) Ribosome

  B) Cytoplasm

  C) Nucleus

  D) cell membrane

  E) chloroplast

  F) Mitochondria

  G) cell wall

  H) vacuole

  I) starch grain

  
• Animal cell

  :

  A) Mitochondria

  B) cell membrane

  C) Cytoplasm

  D) Ribosome

  E) Nucleus

  
• How are carbohydrates stored in animals

  As glycogen
• How are carbohydrates stored in plants?

  As starch
• How are carbohydrates stored in fungi?

  Glycogen
• What are the 5 kingdoms?

  • Plants - Animals - Fungi - Protoctists - Bacteria
• What does multicellular mean?

  Contains many cells
• Define pathogen


  A microorganism which causes disease
• Cell walls are rigid, providing support to the plant cells.
• Chloroplasts contain chlorophyll which absorbs light energy from sunlight
• Virus Structure:

  -A virus is a small, non-living particle that can only reproduce inside a living cell.

  -A protein coat surrounds DNA or RNA
• Bacteria structure:


  • Cell wall
  • No distinct nucleus - have circular chromosomes (nucleoid) and often plasmids
• Protoctist Structure


  • Variable
  • Can be similar to animal cells (protozoa) or plant cells (algae)
• Fungi Structure 


  • Cell wall made of chitin
  • Contain usual organelles (e.g. cytoplasm, cell membrane etc)
  • Hyphae form a network called mycelium
• Virus is uni or multi cellular?


  Unicellular
• Bacteria is uni or multi cellular?

  Unicellular
• Protoctist is uni or multicellular?


  Can be either (most are unicellular)
• Fungi uni or multicellular?


  Can be either
• Viruses are always pathogenic
• Bacteria are sometimes pathogenic
• Protoctists are sometimes pathogenic
• Fungi are sometimes pathogenic
• Give example of a virus:


  HIV (causes AIDS)

  • Influenza
  • Cold virus
  • Measles, mumps, rubella
  • Tobacco mosaic virus (prevents chloroplast production and discolours leaves)
• Give example of a Bacteria:


  • Pneumococcus (causes pneumonia)
  • Lactobacillus bulgaricus (used in yoghurt making)
• Give example of a Protoctist:


  • Chlorella (have chloroplasts, plant-like),
  • Plasmodium (causes malaria)
  • Algae
  • Amoeba (more animal like)
• Give example of a Fungi:


  • Mushrooms
  • Mucor
• Viruses can only reproduce inside another living cell.

  Viruses are Non-living - don’t excrete, respire, move, grow etc
• Fungi use saprotrophic nutrition to obtain nutrients from dead organic matter
• Define saprotrophic nutrition


  The use of digestive enzymes to extracellularly break down dead matter