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Biology - Coggle Diagram
Biology
Cells
Multicellular cells
- Living things are made out of many cells, known as multicellular organisms
- Trillions of cells work together to keep the organism alive
- There are different types of these cells that perform different jobs
Cell theory
- Smallest basic functional unit of life
- Too small to be seen with the naked eye, must use a microscope
- Some organisms only consist one cell, they are consider unicellular organisms; they can include bacteria, amoebas and yeast
- Multicellular consists of multiple cells
- Cells arise from pre-existing cells
- Energy flows within cells
- DNA (Heredity information) is passed from cell to cell
- All cells have the same basic chemical composition
Levels of organisation
- Multicellular organisms consists of many different parts
- These parts all work together
- Each part does a specific job
- The levels of organisation between individual cells and the whole organism are as follows
- Cells
- Tissue
- Organ
- Organ system
- Organism
Cell Types
Eukaryotic cells
- Have a true nucleus containing DNA and membrane bound organelles
- Plant and Animal cells fall into this group
Prokaryotic cells
- No true nucleus
- DNA is coiled up in a region called the nucleoid
- Bacteria and simple algae or some examples
Organelles:
- Cell membrane
- Cell wall
- Nucleus
- Cytosol
- Mitochondria
- Vacuole
- Chloroplast
- Centrosome
- Ribosome
- Smooth endoplasmic reticulum
- Rough endoplasmic reticulum
- Golgi body
Specialized cells
- Each type of cell needs different structures to carry out its job effectively
- Cells vary widely with respect to; shape, size, number of organelles, types of organelles
Specialization allows an animal to survive and adapt to the environmentIn humans:
- Red blood cells
- Intestinal lining cells
- Fat cells
- Sperm
- White blood cells
- Nerve cell
In plants:
- Guard cells
- Xylem cells
- Root hair cells
Stem Cells
What are Stem cells
- Two groups:
- Tissue specific, also known as adult stem cells
- Pluripotent, including embryonic stem cells and iPS cells
Tissue Specific
- Reside in adult tissue
- Can only give rise to cells of that tissue
- Considered multipotent
Embryonic
- Derived from a small group of cells in the early embryo
- iPS cells are pluripotent, can become every cell in the body
In Medicine
- Stem cell therapy, otherwise known as regenerative medicine
- Promotes the repair response of diseased, dysfunctional or injured tissue
Mitosis
What it is
- The process in which cells divide
- Can be seen as injuries healing or body growing
- Creates identical cells
Process
Interphase
- Cells process on a daily basis
- Growth
- DNA Replication
- Carrying out normal cell functions
- What cells will be doing majority of time
Prophase
- Nucleus is still present
- Chromosomes are condensing
Metaphase
- Nucleus disassembles
- Chromosomes line up on the equator of cell
Anaphase
- Chromosomes are split, sister chromatids are seperated
- Move to opposite sides of the cell
- Centriole creates spindles that grab onto chromsome and moves them along
Telophase
- New nuclei are forming on both sides of cell
- This creates two new cells
Cytokinesis
- The final separation
- The cell is split into two cells by splitting the cytoplasm
Microscopes
What is it
- An instrument that uses lenses to make smaller objects appear larger
- Magnification - the process of making an object appear larger
- Different types of microscopes are suited for specific types
- An object under a microscope is known as a specimen
Types of microscopes
Stereo Light
- 300x magnifcation
- Looks at whole parts of large specimens
- Uses two images to make a 3d image
- Bounces light on specimen and outside specimen to view it
- Cannot view structures inside specimens
Compound Light
- Up to 2000x magnification
- Can view thin slices, can be living cells
- Light bounces through slice back into viewer's eye
- Can view cell structure
- Can only view slices of objects
Electron
- 2000000x magnification
- Looks at Non-living specimens
- Outer detail or inner structures can be seen
- Shoots beams of electrons that bounce off specimens
- Costly
- Only views non-living specimen
Measuring
Number conversion
- Use micrometres (µm) and nanometres (nm)
Magnification and FOV
- Area seen through a microscope is a field of view (FOV)
- As magnification increases, FOV decreases
- Magnification and FOV have an inverse relationship
Estimating by comparison
- Calculating FOV indirectly by use of an equation
- Length of small object = length of large object / number of small objects
- The Large object is the FOV, the small object is the specimen
- FOV is measured as a diameter
Magnification
- Eyepiece, ocular lens has a magnification of 10x
- Objective lens has magnifications of 4x, 10x and 40x
- Both multiply together to give total magnifcation, or power
Germination
A seed
- Small embryonic plants inside husk
- Seeds are the reproductive part of a plant
- Seeds can be defined as encapsulated plant embryos
Parts
- Endosperm, food reserves
- Cotyledons, rudimentary leaves
- Seed coat, protective outer covering of a seed
- Embryo, what will become the new plant
- Food supply, provides energy and nutrients
Monocot or Dicot
Monocot
- 1 primary leaf
- Looks like grass
- Examples: Corn, Wheat
Dicot
- 2 leaves
- Examples: Beans, peas
Germination
Process
- Imbibtion - Water fills seed
- Water activates enzymes that begin plant growth
- Seed grows a root to access water
- Seed grows shoots that grow towards the sun
- Shoots grow leaves and begin photmorphogenesis
Germination
- The sprouting of a seed, spore or other reproductive body
- Usually after a period of dormancy
- The absorption of water, the passage of time, chilling, warming, oxygen, light exposure may all operate in beginning the process
Requires:
- Oxygen, for aerobic respiration
- Water, to metabolically activate seed
- Temperature, requires certain temperature conditions
- pH - Sustainable soil pH level to sprout
Others
- Fire
- Freezing
- Digestion
- Washing
- Scarification
Living or Non Living
Acronym 'Mrs Gren' for the characteristics of something that is living
M - Movement
R - Respiration
S - Sensitivity/stimulus
G - Growth
R - Reproduction
E - Excretion
N - Nutrition