Paper 1 - Cells and Organisms Flashcards
Describe organs
A group of different tissues that work together to perform a particular function
What do chloroplasts do?
- In plants only
- Site of photosynthesis
- Contain chlorophyll to absorb light energy
What does the permanent vacuole do?
- In plants only
- It is a sack of plant sap
- Sap contains glucose and water to be used by the plant for aerobic respiraton
What do ribosomes do?
- Site of protein synthesis (where proteins are made)
What do mitochondria do?
- Site of respiration
- Provide cells with ATP energy they require to function
What does the nucleus do?
- Contains genetic material and DNA
- Which controls the cell
Give an example of a prokaryote
- Bacteria cell
Describe organ systems
A group of organs that work together to perform a particular function
Describe organelles
Sub-cellular structures that make up a cell which each have different roles
Describe cells
- Basic structural units that group together to form cell tissues
- Smallest units of life that can replicate independently
Describe organisms
Multiple organ systems working together to form the organism
Give 2 examples of eukaryotes
- Animal cells
- Plant cells
Describe tissues
A group of similar cells that work together to carry out a particular function
What are the levels of organisation?
organelles → cells → tissue → organs → organ systems → organisms
What are the characteristics of living organisms?
M
R
S
C
G
R
E
N
- Movement (independent)
- Respiration
- Sensitivity to surroundings
- Control their internal conditions
- Grow and develop
- Reproductive
- Excrete metabolic waste
- Nutrition is required
Compare prokaryotes and eukaryotes
- Eukaryotes have a nucleus but prokaryotes don’t
- Eukaryotes have mitochondria but prokaryotes don’t
- Prokaryotes have a single strand of DNA containing genes needed to survive/reproduce but eukaryotes don’t
- Prokaryotes have plasmids (extra genes) for antibiotic resistance but eukaryotes don’t
- Prokaryotes have flagella to propel bacteria but eukaryotes don’t
What is the cell wall?
- Plant cells only
- Made of cellulose to strengthen the cell
- Prevents cell from bursting if too much water enters
What is the cytoplasm?
- The site of cellular chemical reactions
What does cell membrane do?
Controls which substances pass into and out of the cell
Describe common features of plants
- multicellular
- contain chloroplasts for photosynthesis
- contain cellulose cell wall
- they store carbohydrates as starch or sucrose
Describe common features of animals
- multicellular
- do not contain chloroplasts so cannot carry out photosynthesis
- no cell wall
- usually have nervous co-ordination
- they can move from one place to another
- they store carbohydrates as glycogen
Describe common features of fungi
- cannot carry out photosynthesis
- body is usually organised into a mycelium made of thread-like structures called hyphae which contain many nuclei
- some are unicellular, some are multicellular
- their cells have walls made of chitin
- they feed by extracellular secretion of digestive enzymes onto food material and absorption of the organic products - saprotrophic nutrition
- they may store carbohydrate as glycogen
Describe common features of protoctists
- microscopic single-celled organisms
- some live in pond water so have features like an animal cell
- Others have chloroplasts and are more like plants
Describe common features of bacteria
- microscopic single-celled organisms
- they have a cell wall, cell
membrane, cytoplasm and plasmid - they lack a nucleus but contain a circular
chromosome of DNA - some bacteria can carry out photosynthesis but most feed off of other living or dead organisms
