GCSE KS4 Key Concepts of Bio

Important People

• robert brown discovered the nucleus
• robert hooke was the first to discover the cell
• Anton von leuwenhuek was the first to discover cells in living tissue

new cells are always formed from the pre-existing cells

cells are structural and functional units of life

• cell theory was postulated by Matthias Schleiden and Theodore Schwann.
  • Theodore Schwann looked at animal cells

Inside the Nucleus

• cells - nucleus - chromatin - chromosome - histone and dna - gene
• during cell division, chromatin structure condenses to become chromosome
• two protein structures in chromosome; histone protein and DNA.
• The dna is coiled around the histone protein. This is the chromosome.

Inside Chloroplast:

Thylakoid- contains chlorophyll; Light reaction takes place

Stroma - enzymes are present; helps dark reaction and synthesis of food

Magnification

light microscopes have limited resolution and magnification

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