2: Organisation of the organism Flashcards
Describe the structure of a plant cell
Cell wall, cell membrane, nucleus, cytoplasm, chloroplasts, ribosomes, mitochondria, vacuoles
Describe the structure of an animal cell
Cell membrane, nucleus, cytoplasm, ribosomes, mitochondria,
What is the difference between structures of a plant and animal cell?
Animal cells do not have chloroplasts, vacuoles, and a cell wall
Describe the structure of a bacterial cell
Cell wall, cell membrane, cytoplasm, ribosomes, circular DNA, plasmids
What is the function of a cell wall?
- stops cells from bursting when they fill with water
- gives shape to cells
- allows water and dissolves substances to pass through freely
What is the function of a cell membrane?
- forms a barrier between the cell and its surroundings
- keeps contents of cell inside
- allows simple substances to enter and leave the cell (e.g. o2, co2 and h2o)
- controls movement of other substances in and out of the cell (e.g. glucose)
- often described as partially permeable
What is the function of a nucleus?
contains cell DNA in form of chromosones which codes for proteins = controls activities and cell division
What is the function of cytoplasm?
jelly-like material WITHIN cell in which reactions occur & contains organelles (enclosed by cell membrane)
What is the function of chloroplasts?
site of photosynthesis, allows plants to converts light energy to glucose
What is the function of ribosomes & RER?
surrounds nucleus + ribosomes are attached. ribsomes ARE THE SIGHT for protein syntheis
What is the function of mitochondria?
site of respiration & provides energy to function
What is the function of a vacuole?
fluid-filled sac (containing salts, sugars & amino acids), which helps maintain shape & firmness of cell
What is the function of circular DNA?
contains the cells’ DNA in the form of a circular loop of DNA (bacterial chromosone) -> controls cell division and development and controls the activities of the cell
What is the function of plasmids?
small rings of DNA -> contains a few genes for chemicals that might help bacterial survival, eg, antibiotic resistance genes
What happens during the division of existing cells?
New cells are produced
What is the function of ciliated cells?
The movement of mucus in the trachea and the bronchi
What is the function of root hair cells?
Absorption
What is the function of palisade mesophyll cells?
Photosynthesis
What is the function of neurones?
Conduction of electrical impulses
What is the function of red blood cells?
Transport of oxygen
What is the function of sperm and egg cells (gametes)?
Reproduction
What is a cell?
It makes up all living organisms and the tissues of the body
What is a tissue?
Many cells with similar structures working together and performing the same (shared) function
What is an organ?
Several tissues working together to perform specific functions
