Cells
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Cells are the building blocks of life
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Cellular theory
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All living organisms are made and comprised of cells
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The simplest organism→ single cell
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More complex organisms like animals and plants are made of many cells, this is called
mutli-cellular
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In multicellular organisms, they have specialised cells to carry out different types of
functions
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Nucleus
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Largest organelle
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Controls the activity of the cell
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Contains chromosomes which carry your genes
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The genes determine which proteins the cell can make
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Components present inside the cell is called organelle
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Nucleus → chromosomes → DNA
Cell surface membrane/Plasma membrane
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It is selectively permeable
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Forms a boundary between the cytoplasm and thee outside of the cell
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Some chemicals can pass through it, this barrier and the cell and control what comes in and
out of the cell
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Cytoplasm
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Jelly like substance which contains all of the organelles
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Many chemical reactions called metabolic reactions take place here
Mitochondria
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Process of respiration takes place here and it is the powerhouse of the cell
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Cells like cells in heart or muscle cells that have more demand for energy usually have more
mitochondria
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Cell wall
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Found only in plant cells
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Plant cell swells up but cannot burst due to cell wall and that stage is called turgid
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It is made of cellulose, which is a non-living material
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It is freely permeable
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It is rigid, so it helps the cell keep its shape
Chloroplast
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Not present in fungi or animal cell only present in plant cells
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Contains chlorophyll
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Chlorophyll is a green pigment, it absorbs light energy to make food in the process of
photosynthesis
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Vacuole
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Found only in plant cells
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Filled with cell sap
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Cell sap is a store of dissolved sugars, minerals, ions and other solutes(sodium chlorine)
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Helps keep the cells shape
Ribosomes
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Protein synthesis take place (produces proteins)
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Found in all kind of cells
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Extremely microscopic
Endoplasmic reticulum
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Rough(presence of ribosomes)
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Smooth(absence of ribosomes)
Types of cells
● Ciliated cell
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Found in the lining of the trachea and bronchi
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Moves mucus upwards
Root hair cell
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Found near the ends of plant roots
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Absorb water and mineral salts
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Increase surface area so more water and mineral can be absorbed
Xylem vessels
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Found in roots, stems and leaves(vascular bundle)
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Transport water and mineral salts(from root to other parts)
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Helps with support
Palisade mesophyll cells
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Found beneath the epidermis of a leaf
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Helps in photosynthesis
Nerve cells
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Found throughout bodies of animals
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Transmit information in the form of electrical impulses
Red blood cells
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Found in the blood of mammals
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Transports oxygen
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To absorb oxygen, it needs more surface area therefore does not have a nucleus
Sperm and egg cells
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Found in testes and ovaries
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Fuse together to produce a zygote
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Sperms are produced by process of spermatogenesis
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Ovary or egg cells are produced by the process of ovagenesis
Plant cells
Animal cells
Have cellulose cell wall outside the cell membrane
Have no cell wall
Have a cell membrane
Have a cell membrane
Have cytoplasm
Have cytoplasm
Have a nucleus
Have a nucleus
Often have chloroplasts containing chlorophyll
Have no chloroplasts
Often have large vacuoles containing cell sap
Have only small vacuoles
Often have starch grains
Don't have starch grain;sometimes have glycogen
granules
Often regular in shape
Often irregular in shape
Type of cell
Where is it found
Function
Ciliated cell
Lining in the trachea and bronchi
Move mucus upward
Root hair cells
Near the ends of plant roots
Absorb water and mineral salts
Xylem vessels
In stems, roots and leaves of
plants
Transport water and mineral
salts; help in support
Palisade mesophyll cells
Beneath the epidermis of a leaf
Photosynthesis
Nerve cells
Throughout bodies of animals
Transmit info in the form of
electrical impulses
Red Blood Cells
In the blood of mammals
Transport oxygen
Sperm and egg cells
In testes and ovaries
Fuse together to produce zygote
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