B1 Cell Structure Flashcards
Are plant cells eukaryotic or prokaryotic?
Eukaryotic
Are animal cells eukaryotic or prokaryotic?
Eukaryotic
What are eukaryotic cells?
Eukaryotic cells have genetic material (DNA) that forms chromosomes and is contained within a nucleus
What are the feature of an animal cell?
Cell membrane, nucleus, mitochondria, ribosomes and cytoplasm
What are the features of a plant cell?
Cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permanent vacuole, chloroplasts, cell wall
What is the function of the cell membrane?
Controls the movement of substances in and out of the cell
What is the function of the nucleus?
Contains DNA, controls the cell
What is the function of the mitochondria?
Where energy is released through respiration
What is the function of ribosomes?
They are the site of protein synthesis
What is the function of the cytoplasm?
It is a jellylike substance where chemical reactions take place
What is the function of the permanent vacuole?
It contains cell sap
What is the function of chloroplasts?
They contain chlorophyll to absorb light energy for photosynthesis
What is the function of the cell wall?
It is made of cellulose which strengthens the cell
Are bacteria cells prokaryotic or eukaryotic?
Prokaryotic
Are bacteria single-celled or multicellular?
Single-celled
What are the characteristics of bacteria cells?
- Single-celled
- No nucleus - have a single loop of DNA
- Smaller than eukaryotic cells
- Have small rings of DNA called plasmids
What are the features of bacteria cells?
Cell wall, cytoplasm, cell membrane, flagellum, bacterial DNA loop (no nucleus), plasmid DNA rings - bacteria may have more than one of these
What is the equation for magnification?
Image size / actual size
What is the equation for image size?
Actual size x magnification
What is the equation for actual size?
Image size / magnification
What can you see with an electron microscope but not with a light microscope?
Sub-cellular structures, such as ribosomes, that are too small to be seen with a light microscope
What are the features of microscopes?
Uses light to form images, living samples can be viewed, relatively cheap, low magnification, low resolution
What are the features of an electron microscope?
Uses a beam of electrons to form images, samples cannot be living, expensive, high magnification, high resolution
What are the 6 types of specialised cells you need to know about?
Sperm cells, red blood cells, muscle cells, nerve cells, root hair cells, palisade cells
NOT A QUESTION - FOR B1 YOU MUST BE ABLE TO DEFINE THE FOLLOWING TERMS:
Cell membrane, cell wall, chloroplast, chromosome, cytoplasm, DNA, eukaryotic, magnification, mitochondria, nucleus, permanent vacuole, plasmid, prokaryotic, resolution, ribosome
How do cells in animals and plants form different types of specialised cells?
Differentiaton
True or false: animal cells can differentiate throughout their lifetimes
False
True or false: plant cells can differentiate at any stage throughout their lifetimes
True
What is the function of a sperm cell?
To fertilise an ovum (egg)
How are sperms cells adapted?
- Tail to swim to the ovum and fertilise it
- Streamlined
- Lots of mitochondria to release energy from respiration, enabling the sperm to swim into the ovum
What is the function of the red blood cell?
Transport oxygen around the body
How are red blood cells adapted?
- No nucleus so more room to carry oxygen
- Contains a red pigment called haemoglobin that binds to oxygen molecules
- Flat bi-concave disc shape to increase surface area to volume ratio
What is the function of a muscle cell?
To contract and relax to allow movement
How are muscle cells adapted?
- Contains protein fibres which can contract to make the cells shorter
- Contains lots of mitochondria to release energy from respiration, allowing the muscles to contract
What is the function of a nerve cell?
To carry electrical impulses around the body
How are nerve cells adapted for their function?
Branched endings, called dendrites, to make connections with other neurones or effectors
2. Myelin sheath insulates the axon to increase the transmission speed of the electrical impulses
What are the branched endings on the ends of nerve cells called?
Dendrites
What is the function of root hair cells?
To absorb mineral ions and water from the soil
How are root hair cells adapted for their function?
- Long projection speeds up the absorption of water and mineral ions by increasing the surface area of the soil
- Lots of mitochondria to release energy for the active transport of mineral ions from the soil
What is the function of a palisade cell?
To enable photosynthesis in the leaf
How are palisade cells adapted for their function?
- Lots of chloroplasts containing chlorophyll to absorb light energy
- Located at the top surface of the leaf where it can absorb the most light energy
What is the structure of the main genetic material in a prokaryotic cell?
Single loop of DNA
Where is DNA found in animal and plant cells?
In the nucleus
What is the resolution of a device?
The smallest change that a device can measure - this could be many things - distance, time, temperature, volume, etc.
What is the equation for total magnification?
Objective lens magnification x eyepiece lens magnification
