2 - Organisation of the organism

• Similarities & differences in the three cells:

  A) all three have

  B) all three have

  C) all three have

  D) animal & plant

  E) animal & plant

  F) plant & bacteria

  G) plant

  H) plant

  I) bacteria

  J) bacteria

  
• Cell membrane:

  • a partially permeable layer that forms a boundary around the cytoplasm
  • prevents cell contents from escaping
  • controls what substances enter and leave the cell
• Ribosomes:

  • tiny particles floating freely or attached to membranes
  • responsible for synthesis of proteins from amino acids
• Cytoplasm:

  • jelly-like, containing particles and organelles
  • contains cell organelles (e.g. mitochondria, nucleus)
  • chemical reactions take place here
• Nucleus:

  • round or oval structure containing DNA in the form of chromosomes
  • controls cell division
  • controls cell development
  • controls cell activities
• Mitochondria:

  • circular, oval shaped organelle
  • responsible for aerobic respiration
  • cells with a high rates of metabolism (e.g. liver cells, require large numbers of mitochondria to provide sufficient energy)
• Animal Cell:

  A) nucleus

  B) ribosomes

  C) cell membrane

  D) cytoplasm

  E) mitochondria

  
• Cell wall:

  • Tough, non-living layer made of cellulose; it surrounds the membrane
  • Prevents plant cells from bursting
  • Freely permeable (allows water and mineral ions to pass through)
• Sap vacuole:

  • fluid-filled space surrounded by a membrane
  • contains mineral ions and sugars
• Chloroplasts:

  • Organelles containing chlorophyll
  • Traps light energy for photosynthesis
• Plant Cell

  A) cell wall

  B) nucleus

  C) chloroplast

  D) cell membrane

  E) cytoplasm

  F) large vacuole

  G) mitochondria

  
• Circular DNA:

  • A single circular chromosome
  • Controls cell division
• Plasmids:

  • Small, circular pieces of DNA
  • Contains genes that carry genetic information to help the processes of survival and reproduction of the bacterium
• Bacteria cells:

  A) plasmid

  B) circular DNA

  C) ribosomes

  D) cell wall

  E) cell membrane

  F) cytoplasm

  
• neurons:

  • function = carry electrical impulses to and from the brain and spinal cord
  • special features = often very long and able to conduct electrical impulses, some have a fatty sheath for insulation
• red blood cells:

  • transport oxygen around the body
  • no nucleus; contain haemoglobin; larger surface area; bi concave shape
• ciliated cells:

  • waft mucus with bacteria and dust away from the lungs (located in respiratory tract)
  • tiny hair called cilia that can move mucus
• egg cells:

  • for reproduction
  • large amount of cytoplasm containing yolk droplets made up of protein and fat, nucleus carries genetic information
• sperm cells:

  • for reproduction, achieved by penetrating an egg cell
  • tail to enable the sperm to swim, nucleus carries genetic information
• palisade mesophyll cells:

  • trap sunlight to make food for the plant by photosynthesis
  • column-shaped cells, packed with chloroplasts
• root hair cells:

  • absorb water and mineral ions
  • hair gives a large surface area