Topic 1 - Cell Biology Flashcards
What types of cells are prokaryotic
Bacteria
What type of cells are eukaryotic
Plants and animals
Nucleus
Contains genetic material
Mitochondria
Aerobic respiration takes place here
Cytoplasm
Chemical reactions happen here
Cell membrane
Holds cell together and controlls what goes in and out
Ribosomes
Where proteins are made
Cell wall
It supports the cell
Permanent vacuole (contains)
Cell sap
Chloroplasts (2)
1.contain green chlorophyll
2.where photosynthesis occurs
Name the 5 parts of a bacteria cell
Cytoplasm
Cell membrane
Cell wall
Circular strand of dna
Plasmid
Magnification =
Image size ÷ real size
Millimeter to micrometer to nanometer
×1000
×1000
Differences between light and electron microscopes
1.Light microscopes use light and lenses
2.Electron microscopes use electrons instead of light and have a higher magnification and resolution.
Parts of a light microscopes (6)
Eyepiece
Coarse adjustment knob
Fine adjustment knob
Light
High and low power objective lense
Stage
What to include when drawing a magnified cell (4)
Title
Magnification
Labels
Real length
What is cell differentiation?
Is the process by which a cell changes to become specialised for its job
What is different about the ability to differentiate in plant and animal cells?
Animal cells loose the ability to differentiate at an early stage.
Plant cells don’t ever loose the ability to differentiated
How are sperms cells specialised for reproduction? (3)
It has a long tail and streamline head to help it swim to the egg
Lots of mitochondria to provide energy needed
Carries enzymes in head to digest through the egg cell membrane
How are nerve cells specialised for rapid signalling? (2)
Long to cover more distance
Have branched connections at their ends to connect the other nerve cells to form a network
How are muscle cells specialised for contraction? (2)
They are long so they have space to contract
Contain lots of mitochondria to generate energy needed
How are root hair cells specialised for absorbing water and minerals? (1)
They grow out of the roots which gives the plant a bigger surface area for absorbing water and mineral ions
What is the genetic material in the nucleus called?
Chromosomes
Body cells normally have how many copies of each Chromosome?
2
What are Chromosomes?
Long lengths of a molecule called dna
What do Chromosomes carry?
A large number of genes
What is mitosis?
When a cell reproduces itself by splitting to form two identical
Why do cells use mitosis?
Grow and develop
Replace cells that have been damaged
What happens during the growth and replication stage of the cell cycle?
1) Before it divides the cell has to grow and increase the amount of subcellular structures such as mitochondria and ribosomes.
2) it then duplicates its dna which is copied to form x shaped Chromosomes.
What happens during the mitosis stage of the cell cycle?
1) the Chromosomes line up at the centre of cell
2) cell fibres pull them apart to opposite ends of the cell
3) membranes form around the Chromosomes which become the nuclei of the 2 cells
4) lastly the cytoplasm and cell membrane divide
What is binary fission?
A type of simple cell division used by prokaryotic cells
The process of binary fission:
1) circular dna and plasmids replicate
2) cell gets bigger and dna strands move to opposite ends of the cell
3)the cytoplasm begins to divide and new cell walls begin to form
4) the cytoplasm divides and makes 2 cells. Each one has one copy of circular dna but can have a variable amount of copies of the plasmids
How do you estimate the number of bacteria in a population?
Mean division time
What is the mean division time?
The average time it takes for one bacterial cell to divide into two
