GCSE B2.1 Cells, tissues and organs

GCSE B2.1 Cells, tissues and organs

1. 1.1 Animal and plant cells

   • All living things are made from cells
   • Most cells have some structures in common
     • Plant cell
       • Nucleus
       • Cytoplasm
       • Cell membrane
       • mitochondria
       • Ribosomes
     • Animal cell
       • Ribosomes
       • Mitochondria
       • Cell membrane
       • Cytoplasm
       • Nucleus
       • Cell wall
       • Chloroplasts
       • Permanent vacuole
   • Plant and animal cells are different because they have different fuctions

2. 1.2 Bacteria and yeast

   • Bacteria
     • Bacterial cells contain
       • Cell membrain
       • Cell wall
       • Cytoplasm
       • Plasmids
       • Flagella
     • No nucleus so the genetic material is stored in the cytoplasm
     • When bacteria multiplies it forms a colony
   • Yeast
     • Single-celled organism
     • Yeast cells contain
       • Nucleus
       • Cytoplasm
       • Membrane
       • Cell wall

3. 1.3 Specialised cells

   • As an organism matures, each cells develops to have their own fuction
   • There are many different types of cell
     • Root hair cell
     • Sperm cell
   • Look at the structures of the cell for a clues about its function

4. 1.4 Diffusion

   • Molecules in gases and liquids move around randomly because of the amount of energy they have
   • Diffusion is the spreading out of gas, or any substance in a solution
   • Concentration gradient - the difference in concentration between two areas is called the
   • Because particles more randomly, there will be a net movement from an area of high concentration to an area of low concentration
   • The larger the difference in concentration, the faster the rate of diffusion

5. 1.5 Tissues and organs

   • Tissues
     • A tissue is a group of cells with a similar structure and function
     • Animal tissues
       • Muscle tissue - contracts to bring about movement
       • Glandular tissue - produces substances like enzymes or hormones
       • Epithelial tissue - Covers some parts of the body
     • Plant tissues
       • Epidermal tissue - Covers the plant
       • Mesophyll - can photosynthesise
       • Xylem and phloem - transport substances around the plant
   • Organs
     • Organs are made of tissue
     • The stomach is an organ made of muscular, glandular and epithelial tissues

6. 1.6 Organ systems

   • Groups of organs work together to make an organ system
     • One example is the digestive system
       • The digestive system turns insoluble molecules into soluble molecules so it can be absorbed into the blood