Topic 1 Cells (section 2) Flashcards
What is an organelle?
Intracellular structure that carries out a specific function within a cell
What is a cell?
Basic unit from which all organisms are made
What is a tissue?
A group of specialised cells which are adapted to carry out a specific function
What is an organ?
A group of tissues adapted to perform a specific function
What is an organ system?
Group of organs that carry out particular functions
What is an organism?
All organs working together in a living ‘thing’
What is the cytoplasm?
Site of chemical reactions in cell / jelly like substance
What is the cell membrane?
Controls entry and exit of molecules in and out of cell
What is the nucleus?
Controls cell’s activities + contains DNA
What are mitochondria?
Site of aerobic respiration and release ATP
What are chloroplasts?
Site of photosynthesis and contain chlorophyll
What is the cell wall?
Strengthens the cell
stops it from bursting
Made of cellulose
What is the vacuole?
Contains cell sap
Stores water, sugars and waste
Gives cell its shape
What are ribosomes?
Site of protein synthesis
What are the similarities between animal and plant cells?
- both contain nucleus, cytoplasm, cell membrane
- both contain ribosomes + mitochondria
- both are eukaryotes (have a nucleus)
What are the differences between animal and plant cells?
- plant cells have vacuole, chloroplasts and cell wall
- aren’t present in animal cell
Why is cell differentiation important in the development of specialised cells?
Cell differentiation allows cells to develop structures and features that enable them to fulfil specific roles and functions
What is the function and structure of the egg cell?
To be fertilised by sperm cell + transfer genetic material to offspring
1. Contains +++ mitochondria (to release energy in respiration)
- Contains half of mother’s DNA
- Very large - easier to be fertilised
What is the structure and function of sperm?
To swim to + fertilise egg cell, transfer genetic material to offspring
1. Flagellum for swimming, stream lined shape
- +++ mitochondria to release energy via respiration
- Acrosome (tip of sperm) contains digestive enzymes -> break down egg membranes
- Contains 1/2 father’s DNA
What is the structure and function of a red blood cell?
Carries o2 around body
1. Haemoglobin -> carry lots of o2
- Biconcave shape -> large SA:Vol ratio for efficient diffusion
- No nucleus -> can carry more o2
What is the structure and function of a nerve?
Carrie electrical impulses between body + brain
- Long thin shape -> faster + covers longer distance
- Myelin sheath to insulate nerve cells + speed up conduction
What is the structure and function of a ciliated epithelial cell?
To aft mucus out of airways (mucus traps bacteria/dust)
- Cilia on surface- hair like structures
- ++++ mitochondria for energy via respiration
What is the structure and function of a small intestine cell?
Releases digestive enzymes and absorbs nutrients from digestion
- Microvilli - large sa vol ratio for absorption
- +++ mitochondria = energy for active transport
What is the structure and function of a palisade cell?
Carry out photosynthesis
- ++= chloroplasts -> contain chlorophyll and absorb light for photosynthesis
Produces glucose that can be used for respiration
What is the structure and function of a root hair cell?
Absorb water + minerals from soil (water - osmosis, mineral - active transport)
- Shape gives larger surface area : volume ratio for osmosis /active transport
What is the structure and function of a xylem cell?
Transport water + solutes from roots to leaves
- Cells are dead- long continuous hollow tubes for water to travel fast
- Cells contain lignin for strength