Organisation of the organism

• Plant cell viewed in light microscope

  • Cell membrane
  • Cell wall
  • Permanent vacuole
  • Cytoplasm
  • Chloroplast
• Plant cell viewed under an electron microscope

  • Cell membrane
  • Cell wall
  • Permanent vacuole
  • Cytoplasm
  • Chloroplast
  • Mitochondrion
  • Chromosomes
  • Ribosomes
  • Nuclear membrane
• Animal cell viewed in a light microscope

  • Nucleus
  • Cell membrane
  • Cytoplasm
• Animal cell under an electron microscope

  • Nucleus
  • Cell membrane
  • Cytoplasm
  • Ribosomes
  • Vacuole (If have)
  • Mitochondrion
  • Chromosomes
  • Nuclear membrane
• Pictures that can be fitted to type of microscopes called MICROGRAPHS.

  • Light Micrographs (photomicrographs) are coloured images.
  • Electron micrographs are black-and-white images.
• Nucleus

  • Contains the genetic materials which control cell activities
  • Needed for cell division
• Cytoplasm

  • Site of chemical reactions
  • Support internal cell structure
  • Jelly-like substance between cell membrane and nucleus
  • Contain water and dissolved substances e.g. sugars, proteins, salts
  • Most cell activities occur
• Cell Membrane

  • Control which substances enter and leave the cell
  • Seperate cell from the environment
• Ribosomes

  • Site of protein synthesis
  • Small round structures in cytoplasm
  • Attached to the membrane of endoplasmic reticulum or in cytoplasm
• Cell Wall

  • Made of cellulose
  • Provide support to the cell
  • Maintain the shape of the cell
  • Protect the cell from injury
• Chloroplast

  • Contains chlorophyll to absorb sunlight and conduct photosynthesis
• Large Permanent Vacuole

  • Contains cell sap
  • Store materials
  • Help support the shape of the cell
  • Small vacuole = Vesicles
  • Fluid-filled space
  • Cell sap contains sugars, mineral ions and amino acid
• Common features between plant and animal cells

  1. Cytoplasm
  2. Cell Membrane
  3. Nucleus
  4. Ribosomes
  5. Mitochondria
• Nuclear Membrane

  • An outer covering that seperates the nucleus from cytoplasm
  • Has pores that allow substances to enter and leave the nucleus
• Chromosomes

  • Thread-like structures within the nucleus
  • Human body cell contains 46 chromosomes
  • Made up of protein and deoxyribonucleic acid (DNA)
  • DNA carries information in the format genes
• Mitochondria

  • Where aerobic respiration takes place and release energy
  • Inner membrane
  • Folded to increase surface area for aerobic respiration
  • Outer membrane
• Organelles present only in plant cells

  1. Chloroplast
  2. Cell wall
  3. Large permanent vacuole
• Differences between animal cells and plant cells

  ANIMAL CELLS

  • No cell wall
  • No chloroplast
  • No large permanent vacuole
  • Irregular shape
  • Smaller in size
  • Carbohydrate stored in the form of glycogen

  PLANT CELLS

  • Have cell wall
  • Have chloroplast
  • Have large permanent vacuole
  • Fixed shape
  • Larger in size
  • Carbohydrate stored in the form of starch
• Bacteria Cell

  • Cell wall made of peptidoglycan or murein
  • Cytoplasm
  • Cell membrane
  • Circular loop of DNA (Chromosomal DNA)
  • Plasmid (contain additional genetic information that gives the bacterium unique qualities)
  • Ribosomes
  • Flagellum
  • No nucleus or membrane-bound structures
• Differentiation is a process by which a cell becomes specialised for a specific function.
• Examples of specialised cells (ANIMAL CELLS)

  • Ciliated cell
  • Nerve cell
  • Red blood cell
  • Sperm cell
  • Ovum cell
• Examples of specialised cells (PLANT CELLS)

  • Root Hair cell
  • Palisade Mesophyll cell
• Ciliated cells

  A) Cilia are extensions of the cell membrane

  B) MUCUS

  C) Cytoplasm

  D) Mitochondrion

  E) Nucleus

  F) Cell membrane

  
• Ciliated Cells

  • Functions
  • Move mucus in trachea and bronchi.
  • Adaptations
  • Hair-like structure called cilia to beat to move the mucus.
• Neurone / Nerve cell

  • Function
  • Send nerve impulses
  • Adaptations
  • Long nerve fiber
  • Axon insulated with myelin sheath which speed up the transmission of impulse

  A) Cell body

  B) Ribosome

  C) Dendrites

  D) Nucleus

  E) Cell membrane

  F) Cytoplasm

  G) Axon

  H) Myelin sheath (made from schwann cells)

  I) Nerve ending

  
• Red Blood Cell

  • Function
  • Transport oxygen throughout the body
  • Adaptations
  • Biconcave disc shape to increase surface area for efficient diffusion of oxygen
  • No nucleus, to make more space for haemoglobin
  • No mitochondria, stop the red blood cells from using up all the oxygen for themselves
  • Contains haemoglobin that binds to oxygen

  A) Cytoplasm containing hydrogen

  B) Cell membrane

  C) Biconcave shape due to lack of nucleus

  
• Sperm Cell

  • Function
  • Reproduction
  • Adaptation
  • Head has nucleus carrying genetic information
  • Have a tail to swim
  • Acrosome in head contains digestive enzyme to penerate ovum
• Sperm Cell

  • Function
  • Reproduction
  • Adaptation
  • Head has nucleus carrying genetic information
  • Have a tail to swim
  • Acrosome in head contains digestive enzyme to penetrate ovum
  • Many mitochondria releasing energy for it to swim

  A) HEAD

  B) ACROSOME

  C) Cell membrane

  D) Nucleus

  E) Mid-piece

  F) Cytoplasm

  G) Tail/Flagellum

  H) Mitochondria

  
• Ovum Cell

  • Function
  • Reproduction
  • Adaptation
  • A lot of cytoplasm which has nutrients for embryo to grow
  • Nucleus containing genetic information
  • Cell membrane changes after fertilization, prevent other sperm from entering the egg

  A) Follicle cell

  B) Cytoplasm

  C) Nucleus

  D) Mitochondrion

  E) Cell membrane

  F) Zona pellucida

  G) Yolk droplets

  
• Root Hair Cell

  • Function
  • Absorb water and minerals from the soil
  • Adaptations
  • Root hair increase surface area for absorption
  • Walls are thin to absorb water and minerals efficiently

  A) Ribosomes

  B) Mitochondrion

  C) Nucleus

  D) Cytoplasm

  E) Vacuole

  F) Root hair

  G) Cell wall

  H) Cell membrane

  
• Palisade Mesophyll Cell

  • Function
  • Photosynthesis
  • Adaptation
  • Long cylindrical shape for large surface area to absorb sunlight
  • Contain many chloroplasts to absorb maximum sunlight for photosynthesis

  A) Cytoplasm

  B) Ribosomes

  C) Nucleus

  D) Chloroplasts

  E) Mitochondrion

  F) Cell wall

  G) Vacuole

  
• Cells are basic functional and structural units in a living organism.
• Tissues are groups of cells of similar structure working together to perform the same function.
• Organs are made from different tissues working together to perform the same function.
• Organ systems are groups of organs with related functions, working together to perform body functions.
• Examples of organ system

  • Shoot system

  Examples of organs

  • Leaf, stem, flower, fruit

  Examples of tissues

  • Epidermis mesophyll
  • Xylem
  • Phloem
• Examples of organ system

  • Root System

  Examples of organs

  • Root, Tuber

  Examples of tissues

  • Ground Tissue
  • Xylem
  • Phloem
• Examples of organ system

  • Digestive system

  Examples of organs

  • Oesophagus, stomach, small intestine, large intestine

  Examples of tissues

  • muscle
  • connective
  • nerve
  • epithelial
• Cell -> Tissue -> Organ -> Organ system -> Organism
• Stomach

  • contains gland tissue, muscle tissue and nerve tissue
  • gland tissue secretes enzymes to digest food
  • muscle tissue contracts to churn and mix food with enzymes
  • nerve tissue detects presence of food