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Key concepts in biology 1 - Coggle Diagram
Key concepts in biology 1
Cells
Eukaryotes
Animal and plant cells
Genetic material enclosed in a nucleus
Have a cell membrane
Prokaryotic
single celled organisms
genetic material isn't in a nucleus, in a single loop of DNA
Much smaller than Eukaryotic cells
Have a cell membrane and a cell wall
Subcellular structures
Animal cells
Cell membrane - Controls what goes in (oxygen) and what goes out (Carbon dioxide) of the cell. Holds it together
Cytoplasm - Gel like substance when most of the chemical reactions take place, contains enzymes which speed up the rate of reaction. Organelles are found in it
Mitochondria - Site of aerobic respiration, energy released from glucose is used to fuel the cells reactions
Ribosomes - Site of Protein synthesis, enzymes are made
Nucleus - Contains genetic material arranged in chromosomes than controls the activities of the cell, Enclosed in a nuclear membrane
Plant cells
Usually have what's in an animal cell, but some extra things as well
Chloroplasts - contain chlorophyll, which absorbs the light needed for photosynthesis, site of it aswell
Cell wall - made from cellulose which strengthens the cell
Large permanent vacuole - contains cell sap, weak solution of sugar and salts. Gives the cell its shape and improves cell's rigidity
Bacterial cells
Cell membrane
Ribosomes
Cell wall - used for protection, not made from cellulose
Plasmid DNA - Extra circles of SNA, contain addition genes like drug resistance
Chromosomal DNA - A single loop of DNA that lies free in the cytoplasm
Cytoplasm
Flagellum - Some have them, used to help the bacterium move away from harmful substances like toxins, or towards beneficial things like nutrients
Order of systems
Cell: smallest unit of a licing organism
Tissue: a group of cells with a similar structre and function
Organ: made of more than one type of tissue which work togethter to perform a particulr job
System: composed of a variety of different organs which work toether to perform a perticular function in the body
Specialised cells adaptions
Sperm cells
Flagellum, allows the sperm cells to swim to the egg cell
Has many mitchondria: release energy needed to propel the sperm
Haploid nucleus: Has 23 chromosomes, fuses with the egg nucleus to form a diploid zygote
Acrosome: contains enzymes to digest a way through the egg cell membrane
Produced in large numbers to increase fertilization chance
Egg cells
Contains nutrients in the cytoplasm to supply the growing embryo
Haploid nucleus that can fuse with another haploid nucleus form the sperm to form a siploid zygote
After fertilization, the membrane changes structure to stop any sperm getting in, it becomes impermeable
Large size and cyloplasm to allow quick, repeated division as the embryo grows
Ciliated epithelial cells
Have cilia in the top surface of the cell. The cilia traps potentially dangerous substances, and moves them back up to the throat were it can be swallowed
Protects the body against disease
Plant specialised cells
Root hair cells
Specialised to take up water by osmosis and mieral ions by active transport from the soil as they are found in the tips of roots
Have large surface area, meaning that there is more space for water absorbtion
Mitochondia to provide energy from respiration for the active transport of mineral ions into the root hair cell
Xylem cells
Specialised to transport water and mineral ions up the plan from the roots to the shoots
Upon formation, a chemical called lignin is deposited, causing the cell to die. They then become hollow and are joined end-to-end to form a continuous tube so water and mineral ions can move through
Lignin is desposited in spirals which helps the cells withstand the pressure from the movement of water
Phloem cells
Specialised to carry the products of photosynthesis from sources to sinks
Cell walls of each cell form structures called sieve plates when they break down, allowing the movement of substances from cell to cell
Despite losing many sub-cellulr structures, the energy these cells need to be alive is supplied by the mitochondria of the companion cells