WHAT IS A CELL?
Cells are the building blocks of all things living. A blood cell is about 2 micrometers long and could fit over 60,000 on the head of a pin. "The cell theory states that: -All living things are made of cells (one or more) -The cell is the basic unit of life -Cells arise from pre-existing cells. The modern cell theory includes the ideas that: -Energy flows occur within cells -DNA is passed from cell to cell -All cells have the same basic chemical composition."
3 MAIN TYPES OF CELLS.
Animal, plant and fungi are the 3 main groups of the Eukaryotic cellular division. Eukaryotes are the cells that have Mitochondria, a nucleus and have evolved to be multicellular (although some are still single celled).
Fungi cells have: -a cell wall, -a nucleolus ("The nucleolus is the nuclear subdomain that assembles ribosomal subunits in eukaryotic cells."), -a nucleus (control centre of a cell), -mitochondria (Powerhouse of the cell), -vacuoles (contain water) -and cytoplasm (the liquid the organelles float in). An animal cell has: -lysosomes (breaks down complex chemicals), -nucleus, -Golgi complex (packages proteins for export out of the cell), -rough endoplasmic reticulum (makes proteins), -smooth endoplasmic reticulum (makes fats and oils) -and ribosomes (makes proteins). A plant cell has: -a cell wall, -a vacuole, -a nucleus, -a nucleolus, -ribosomes, -cytoplasm, -Rough endoplasmic reticulum, -Smooth endoplasmic reticulum, -mitochondria, -Golgi complex -and chloroplast. |
PLANT CELLFUNGAL CELL
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HOW DO PROKARYOTIC AND EUKARYOTIC CELLS REPRODUCE?
Prokaryotic cells ,the other division of cell type (e.g bacterial cells), have no nucleus, no mitochondria but instead have a free floating strand of DNA or RNA. They reproduce through a process called binary fission. In a prokaryotic cell there is 1 strand of free floating DNA in the cytoplasm. In binary fission that single strand of DNA is the first thing to duplicate which after duplicating attaches itself to the plasma membrane. Then the 2 chromosomes go to opposite ends of the cell. The plasma membrane in the middle of the cell grows inwards until it closes to separate the cell into 2 sections, each with everything a cell could need. The cell then "fissions" at the centre forming 2 new cells.
The life of a eukaryotic cell is categorized into 2 main sections, the inter phase and the cell division. In the inter phase, the cell grows, takes in nutrients and proteins and duplicates its chromosomes. During the cell division phase the nucleus splits in a process called mitosis. Then the divided nuclei are established in different cells in a process called cytokinesis.
The life of a eukaryotic cell is categorized into 2 main sections, the inter phase and the cell division. In the inter phase, the cell grows, takes in nutrients and proteins and duplicates its chromosomes. During the cell division phase the nucleus splits in a process called mitosis. Then the divided nuclei are established in different cells in a process called cytokinesis.