CELLS AND MICROSCOPY PMT Flashcards
State the two types of cells
-Eukaryotic (animal and plants)
-Prokaryotic
what is the difference between a eukaryotic and prokaryotic cell?
A eukaryotic cell contains a nucleus and membrane bound organelles. A prokaryotic cell does not.
how is genetic information stored in a eukaryotic cell?
Within the nucleus, arranged in chromosomes
Other than storing genetic information, what is the function of the nucleus?
controls cellular activities
describe the structure of cytoplasm
- Fluid component of the cell
- Contains organelles, enzymes and dissolved ions and nutrient
What is the function of the cytoplasm?
sight of reactions e.g. first stage of respiration
what is the function of the cell membrane?
Controls the entry and exit of materials in and out the cell
what is the function of mitochondria?
Site of respiration
what is the function of ribosome?
Join amino acid in a specific order
which organelles are found only in plant cells?
- Permanent vacuole
- Cell wall
- Chloroplast
what is the cell wall made of?
Cellulose
What is the function of the cell wall?
- provide strength
- Prevents the cell bursting when water enters by osmosis
what does the permanent vacuole contain?
A solution of salt, sugars and organic acids
What is the function of the permanent vacuole?
supports the cell
What is the function of chloroplasts?
site of photosynthesis
When looking at a cell using a microscope, why do chloroplast appear green?
They contain chlorophyll, which is a green pigment
List the organelles found in prokaryotic cells
- Chromosomal DNA
- Plasmid DNA
- Cell wall
- Cell membrane
- Ribosomes
- Flagella
how is genetic information stored in a prokaryotic cell?
Found free in the cytoplasm as:
- Chromosomal DNA
- Plasmid DNA
what is the prokaryotic cell wall composed of?
Peptidoglycan
what is a flagellum
- Long, rotating, whiplike protrusion
what is a haploid cell?
A cell that contains a single copy of each chromosome e.g. 23 chromosomes in humans
what is a diploid cell?
A cell that contains two copies of each chromosome e.g. 46 chromosomes in humans
what are gametes?
- reproductive cells (e.g. egg and sperm cells)
- they are haploid cells
Describe how egg cells are adapted to their function
-Haploid nucleus contains genetic material
-Mitochondria in cytoplasm produce energy for the developing embryo
-Cell membrane hardens after fertilisation, preventing the entry of other sperm and ensuring the zygote is diploid
Describe how sperm cells are adapted to their function
-Haploid nucleus contains genetic information
-Tail enables movement
-Mitochondria provide energy for tail movement
-Acrosome contains enzymes that digest the egg cell membrane
where are ciliated epithelial cells found?
found lining the surface of structures such as the respiratory tract and uterus
Describe the function of ciliated epithelial cells lining the airways
Move in synchronised waves to beat mucus up to the back of the throat where it can be swallowed
what is magnification
the number of times bigger an image appears compared to the size of the specimen
how can the magnification of an image be calculated
magnification = size of image
——————-
size of specimen
what is resolution
the ability to distinguish between two different points
what are the advantages of light microscopes
- cheap
- easy to use
- portable
- coloured images
what is the advantage of electron microscope
greater magnification and resolution
what are the disadvantages of electron microscopes
-expensive
-large so less portable
-require training to use
-only dead specimens can be used
how do you convert m to mm
x 1000
how do you convert m to um
x 1,000,000
how do you convert m to nm
x 1,000,000,000 (x10^9)
how do you convert nm to m
divide by 1,000,000,000 (x10^-9)
