1 - Structures and Functions in Living Organisms Flashcards Preview

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Flashcards in 1 - Structures and Functions in Living Organisms Deck (45)
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What are the characteristics of all living organisms?

M - move
R - respiration
S - sensitivity
C - control
G - growth
R - reproduction
E - excreting
N - nutrition


What is in an animal cell?

Cell membrane


What is in a plant cell?

Cell membrane
Cell Wall


What is the function of a nucleus?

An organelle which contains the genetic material that controls the cell's activity. Surrounded by its own membrane


What is the function of a cell membrane?

Forms the outer surface of the cell and controls what goes in and out


What is the function of cytoplasm?

A gel-like substance where most of the cell's chemical reactions happen. Contains enzymes which control these reactions


What is the function of chloroplasts?

Contains a green substance called chlorophyll which enables photosynthesis


What is the function of a cell wall?

A rigid structure made of cellulose which surrounds the cell membrane. Supports and strengthens the cell


What is the function of a vacuole?

A large organelle that contains cell sap (a weak solution of sugars and salts). Also helps to support the cell


What is the function of cells?

They are specialised to carry out a particular function and their shape, size and strength can vary (e.g.. red blood cells carry oxygen)


What are tissues?

A group of similar cells that work together to carry out a particular function. Can contain more than one cell type (e.g. xylem tissues carry water in plants)


What are organs?

A group of different tissues that work together to perform a function (e.g. lungs in mammals)


What are organ systems?

Organs work together to form organ systems. Each system does a different job (e.g. in mammals the digestion system is made up of organs such as the stomach and intestines)


What are typical plant features?

- Multicellular
- Contain chloroplasts for photosynthesis
- Have cell walls made of cellulose
- Store carbohydrates as sucrose or starch


What are examples of plants?

- Cereals (e.g. maize)
- Herbaceous legumes (e.g. peas and beans)


What are typical animal features?

- Multicellular
- No chloroplasts
- No cell walls
- Most have some kind of nervous coordination meaning they can respond rapidly to changes in their environment
- Can move from one place to another
- Store carbohydrates in the form of glycogen


What are examples of animals?

- Mammals (e.g. humans)
- Insects (e.g. houseflies or mosquitos)


What are typical fungi features?

- Some are single-celled
- Others have a body called a mycelium which is made from hyphae that contains lots of nuclei
- Cannot photosynthesise
- Cell walls made of chitin
- Feed by saprotrophic nutrition
- Store carbohydrates as glycogen


What are examples of fungi?

- Yeast (single-celled fungi)
- Mucor (multicellular and has a mycelium and hyphae


What is saprotrophic nutrition?

When an organism secretes extracellular enzymes into the area outside their body to dissolve their food so they can then absorb the nutrients. Fungi sometimes feed this way.


What are typical protoctists features?

- Single-celled
- Microscopic
- Some have chloroplasts and are similar to animal cells
- Look like a fish with string as a tail


What are examples of protoctists?

- Chlorella (plant-cell-like)
- Amoeba (animal-cell-like and lives in pond water)


What are typical bacteria features?

- Single-celled
- Microscopic
- No nucleus
- Circular chromosome of DNA
- Some can photosynthesise
- Feed off other organisms (both living and dead)
- Look like a sideways plant cell with a 'dog' DNA strand


What are examples of bacteria?

- Lactobacillus bulgaricus (used to make milk go sour and turn into yoghurt, rod shaped)
- Pneumococcus (round in shape)


What are typical virus features?

- Particles, rather than cells
- Smaller than bacteria
- Parasite (can only reproduce inside living cells)
- Infect all types of living organisms
- Come in loads of shapes and sizes
- no cellular structure (protein coat around some DNA or RNA)
- Hexagon with protein squiggle inside


What are examples of viruses?

- Influenza virus
- Tobacco mosaic virus (makes the leaves in tobacco plants discoloured by stopping chloroplasts being produced)


What are pathogens?

Organisms that cause a disease. Can include some fungi, protoctists, bacteria and viruses


What are examples of pathogens?

Protoctists - Plasmodium (causes malaria)
Bacterium - Pneumococcus (causes pneumonia)
Viruses - influenze virus (causes flu) and HIV (which causes AIDS)


What are enzymes?

A biological catalysts - speeds up all the reactions in the body.
It is a protein (made of amino acids) and is specific meaning it will only catalyse one type of reaction.
Optimum temperature is 37*C - above this is becomes denatured


What is a substrate?

A molecule that has been changed in a reaction