1. Cell Structure Flashcards
What is a eukaryotic cell?
- It has a nucleus.
- They usually have mitochondria.
- In plants cells only they have chloroplasts.
What is a prokaryotic cell?
- bacterial cell
- no nucleus
- genetic material is a single loop of DNA
Differences between prokaryotic and eukaryotic cells
(4)
- much smaller in size
- the genetic material is not enclosed in a nucleus
- the genetic material is a single DNA loop and there may be plasmids
- they do not contain mitochondria or chloroplasts.
What is a nucleus?
Controls all activities of the cell.
What is cytoplasm?
A liquid gel in which most of the chemical reactions take place.
What is cell membrane?
Controls what passes in and out of the cell.
What are mitochondria?
where aerobic respiration takes place
What are ribosomes?
Where protein synthesis occurs and synthesis for all other proteins in the cell.
What is a cell wall?
Made of cellulose it strengthens the cells and gives it support.
What are chloroplasts?
They absorb energy from the sun to make food by photosynthesis.
What is a permanent vacuole?
A space in the cytoplasm filled with cell sap that keeps the cells rigid to support the plant.
What is cell differentiation ?
the process by which a cell changes to become specialised for its job
What are specialised cells?
Cells specialised to carry out a particular function.
What are adaptations of root hair cells?
- long hair that sticks out into the soil which gives the plant a large surface area to increase the rate of absorption.
- They also contain lots of mitochondria, which release energy from glucose during respiration in order to provide the energy needed for active transport
What is the function of a root hair cell?
Enables plants to take in water and mineral salts.
What are the adaptations of a sperm cell?
- It has a middle section full of mitochondria to release energy.
- long tail and streamlined head to help it swim to the egg
- The acrosome in the head contains digestive enzymes so that the sperm can penetrate an egg.
What is the function of a sperm cell?
To fertilise egg cells.
What are the adaptations of red blood cells?
- cytoplasm contains haemoglobin to transport oxygen
- no nucleus - can contain more haemoglobin
- biconcave shape to maximise surface area
What is the function of a red blood cell?
To carry oxygen.
What does a red blood cell NOT have?
A nucleus.
What is the function of a nerve cell?
To send nerve impulses around the body.
what are the adaptations of nerve cells?
They are thin and long. This means they can carry messages up and down the body over large distances.
Nerve cells have branched connections at each end. These join to other nerve cells, allowing them to pass messages around the body.
They have a fatty (myelin) sheath that surrounds them. The fatty sheath increases the speed at which the message can travel.
What is the equation for magnification?
Magnification = size of image (I) / actual size (A)
What are fat cells?
Storage cells. They help animals to survive when food is in short supply.
