Structures and Functions in Living Organisms Flashcards
(26 cards)
Characteristics of living organisms
Movement, Respiration, Sensitivity (response) , Growth, Reproduction, Excretion, Nutrition & Control (homeostasis).
Organelles in animal cells
Nucleus, Cell Membrane & Cytoplasm
Organelles in plant cells
Nucleus, Cell Membrane, Cytoplasm, Cell Wall, Vacuole & Chloroplasts.
Nucleus
Contains genetic material that controls the cell’s activities. It is surrounded by its own membrane.
Cell Membrane
Controls the substances that go in and out of the cell.
Cytoplasm
A gel-like substance. It is where most of the chemical reactions in the cell take place. It contains enzymes that control the reactions.
Chloroplasts
Where photosynthesis takes place. Chloroplasts contain a green substance called chlorophyll which is used in photosynthesis.
Cell Wall
It surrounds the cell membrane, strengthening and supporting the cell.
Vacuole
A large organelle that contains cell sap. It helps to support the cell.
What colour is chlorophyll?
Green
What is cell sap?
A weak solution of sugars and salts.
Why do cell structures vary?
They are specialised to carry out a specific function.
What are tissues made up of and what do they do?
Similar cells and they work together to carry out a specific function.
What are organs made up of and what do they do?
A group of different tissues that work together to carry out a specific function.
Features of plants
- Multicellular
- They have chloroplasts so can photosynthesise
- They have cells walls made of cellulose
- They store carbohydrates as sucrose or starch
Examples of plants
- cereals (e.g. maize)
- herbaceous legumes (e.g. peas and beans)
Features of animals
- Multicellular
- No chloroplasts and they can’t photosynthesise
- No cell walls
- Most have some kind of nervous coordination so can respond to changes in their environment rapidly
- Usually they can move
- Often store carbohydrate as glycogen
Examples of animals
- mammals (e.g. humans)
- insects (e.g. houseflies and mosquitoes)
What do animals store carbohydrates as?
Glycogen
What do plants store carbohydrates as?
Sucrose or starch
Features of fungi
- Some are single-celled
- Others have a body called mycelium
- They can’t photosynthesise
- Cell walls are made of chitin
- Most feed by saprotrophic nutrition
- Store carbohydrate as glycogen
What is mycelium?
A body made up of thread-like structures called hyphae which contain lots of nuclei.
What is saprotrophic nutrition?
Extracellular enzymes are secreted into the area outside the body to dissolve the food. The nutrients are then absorbed.
What do fungi store carbohydrates as?
Glycogen
