Living Organisms And Cell Structure Flashcards
What characteristics do all living organisms share ?
They all require nutrition
They all respire
They all respond to their surroundings
They all excrete their waste
They all move
They control their internal conditions
They reproduce
They grow and develop
Common features of plants
Multicellular
Contain chloroplasts/ can photosynthesise
Cell wall made from cellulose
Store carbohydrates as starch or sucrose
E.g. maize - used for cereals
What does mitochondria do
Generates most of the cells chemical energy needed to power the biochemical reactions
What does a vacuole do
Stores carbohydrates as starch or sucrose
Common features of an animal cell
Multicellular
Don’t contain chloroplasts so don’t photosynthesise
No cell wall
Have nervous coordination
Can move from one place to another
Store carbs as glycogen
Example- mammals
Common features of fungi cells
Multicellular
Don’t have chloroplasts so don’t photosynthesise
Cell wall made from chitin
Thread like structures called hyphae which form a network called mycelium
Saprotrophic nutrition - extra cellular secretion of enzymes onto dead matter
Example - yeast used in beer and bread making
Common features of protoctists
Microscopic single called organisms
Some have animal cell properties ( amoeba )
Some have plant cell properties ( chlorella )
A pathogenic example is plasmodium which causes malaria
Common features of a bacteria
Microscopic single called organisms
Have a cell wall, cell membrane, cytoplasm and plasmids
Don’t have a nucleus but to have a circular chromosome of DNA
Some carry out photosynthesis but most feed off dead matter
Example is a lactobacillus which is used in the production of yoghurt from milk
Common features of viruses
Non living organisms
Parasitic and only reproduce inside living cells
Infect every type of living organism
No structure but have a protein coat and contains 1 type of nucleic acid either DNA or RNA
Example - tobacco mosaic virus - caused discolouring of leaves in a tobacco plant
What are the levels of organisation and an example of each
Organelle level - mitochondria
Cell level - heart muscle cell
Tissue level - heart muscle tissue
Organ level - heart
Organ system level - circulatory system
Organism level - deer
What is the importance of cell differentiation
Allows organisms to develop cells necessary to grow and develop as specialised cells that can undertake and carry out specific functions
Advantages of stem cells in medicine
Great potential to treat a wide variety of diseases from diabetes to paralysis
Organs developed from a patients stem cells reduces risk of organ rejection and the need to wait for an organ donor
Adult stem cells are already used in a variety of treatments acting as proof of benefits
Disadvantages of stem cells in medicine
Stem cells cultured in a lab could become infected with a virus which could be transmitted to the patient
There is a risk of cultured stem cells accumulating mutations that can lead to them developing into cancerous cells
Low numbers of stem cell donors
