Cell Biology Flashcards
(34 cards)
Name the two main types of cell?
Prokaryotic, eukaryotic
Name the two main types of eukaryotes
Plants, animals
Name 3 organelles ALL eukaryotes have.
Cell membrane, cytoplasm, nucleus
Name three organelles prokaryotic cells ALWAYS have
Cell membrane, cytoplasm, cell wall
How is DNA stored in prokaryotic cells?
All DNA is found in a single loop, and there may be one or more smaller rings or DNA called plasmids.
What do nuclei do, and what does it contain?
They contain DNA which controls the cell
What do cell membranes do?
They control what enters and leaves the cell
What do mitochondria do and what do they contain?
They contain enzymes that allow aerobic respiration to occur
What do chloroplasts do and what do they contain?
They contain enzymes and chlorophyll that allow photosynthesis to occur
What do plasmids do and what do they contain?
They contain DNA that enhances the survival of an organism.
What do cells walls do and what do they contain?
They contain cellulose that strengthens the cell.
What does cytoplasm do and what does it contain?
It contains enzymes which allow chemical reactions to take place in the cell
What do ribosomes do and what do they contain?
They contain enzymes which allow protein synthesis to occur
What 5 organelles do most animal cells contain?
Nucleus, Cytoplasm, Cell Membrane, Mitochondria, Ribosomes
What 3 organelles do plants often have that animal cells don’t.
Chloroplasts, Permanent Vacuole, Cell Wall
How are sperm cells adapted to their function?
They have an acrosome which contains enzymes which break down an egg’s wall. They also contain half the amount of chromosomes in the nucleus so that when it fertilises an egg the embryo has one full set of DNA. They contain many mitochondria to provide the cell with enough energy to swim towards the egg, and they a flagellum which makes the cell streamlined so it can swim to the egg faster.
How are nerve cells adapted to their function?
They have a long thin axon, which allows electrical signals to travel very fast without hitting a synapse. They have an insulating myelin sheath which makes the signal travel faster, and they have many dendrites so they can receive signals from many cells.
How are muscle cells adapted to their function?
They are long so can slide over each other easily. They contain lots of mitochondria so the cell has enough energy to contract to cause movement. They contain glycogen which can be converted to glucose for respiration so the cell can contract to cause movement.
How are root hair cells adapted to their function? Explain four ways.
They have a large protrusion which increases surface area so diffusion and osmosis is faster. They have a large permanent vacuole that stores water so there is a larger water concentration gradient for osmosis. They have many mitochondria to provide energy for active transport. They have no chloroplasts to make room for other organelles and because there is no light for photosynthesis underground.
How are xylem cells adapted to their functions? Explain three ways.
They are hollow which allows them to transport water up and down the cell. They contain lignin which strengthens the cell so they can withstand water pressure, and they are dead so they do not use up unnecessary nutrients.
How are phloem cells adapted to their function? Explain two ways.
They have sieve plates which allows them to form tubes which sugar can be transported. They also have almost no organelles so that there is more room for dissolved substances to be transported. This means that the cell must have companion cells to provide it with nutrients.
Explain the importance of cell differentiation.
It allows unspecialised stem cells to become specialised cells, and it allows cells to perform specific functions. This makes it important for growth and development of embryos and seedlings, and for repair of blood and plant tissue.
Explain what happens during cell differentiation?
It acquires different sub-cellular structures to enable it to carry out a certain function.
How have microscopy techniques developed over time?
Light microscopes were invented hundreds of years ago. Light microscopes have developed to be easier to use and have a higher magnification. The invention of electron microscopes increased magnification and resolution.
