Topic 1: Key Concepts Flashcards
What are eukaryotes?
Cells which have a nuclei
What are prokaryotes?
Cells that don’t have a nuclei but do have DNA
Examples of eukaryotes?
Plant and animal cells
What 5 sub cellular structures do animal cells have?
Nucleus
Cytoplasm
Ribosomes
Cell membrane
Mitochondria
What 8 sub cellular structures do plant cells have?
Nucleus
Cytoplasm
Ribosomes
Cell membrane
Mitochondria
Cell wall
Chloroplasts
Vacuole
What is an example of a prokaryote?
Bacterial cell
What 5 sub cellular structures do bacterial cells have?
Cell membrane
Ribosome
Chromosomal DNA
Plasmid DNA
Flagellum
What is the function of the nucleus? (Plant and animal cells)
Controls activities of the cell and contains DNA
What is the function of the cell membrane? (Plant, animal and bacterial cells)
Controls what goes in and out of the cell
What is the function of the mitochondria? (Plant and animal cells)
Where aerobic respiration occurs - releases energy
What is the function of the ribosomes? (Plant, animal and bacterial cells)
Where proteins are made in protein synthesis
What is the function of the cytoplasm? (Plant and animal cells)
Where chemical reactions occur
What is the function of the chloroplasts? (Plant cells only)
Where photosynthesis happens - contains chlorophyll to absorb sunlight
What is the function of the vacuole? (Plant cells only)
Keep the cell rigid for support, contains cell sap and water and maintains the internal pressure of the cell
What is the function of the cell wall? (Plant cells only)
Made of cellulose - strengthens the cell and stops it from bursting
What is the function of the chromosomal DNA? (Bacterial cells only)
Controls cells activities and replication
What is the function of the plasmid DNA? (Bacterial cells only)
Can be be passed between bacteria and used for genetic engineering
What is the function of the flagellum? (Bacterial cells only)
Used for movement
What was the first microscope?
A light microscope with a magnification of x30
What is the most modern type of microscope?
Electron microscopes
What are properties of the most modern microscope and why is this beneficial?
Have a higher magnification and resolution than light microscopes
Allowing us to see smaller things in more detail, so we can understand sub cellular structures better now
Advantages of electron microscopes?
High resolution
Can magnify up to x500,000
Possible to investigate a greater field depth
Disadvantages of electron microscopes?
Expensive
require a specialist to use it
Specimen must be fixed in a vacuum and therefore dead
How can you calculate the overall magnification of a microscope?
Eyepiece magnification x objective magnification
Simple conversions (cm, mm, um, nm)?
cm -x10- mm -x1000- um -x1000- nm
nm -÷1000- um -÷1000mm- mm -÷10- cm
How to calculate actual size of an organism?
Actual size = image size/magnification
What is the actual size calculation triangle?
I
——
A | M
What part of the microscope do you look through?
Eyepiece lens
What part of the microscope do you use to get a clear image?
Coarse focus nob
What is the part of a microscope that you put the specimen on?
Stage
What is a specialised cell?
A cell that has a structure adapted to its function
What does an egg cell do?
Carries female DNA and feeds the developing embryo
What are the structures of egg cells that have adapted to their function? What do they do?
Cell membrane - changes structure after fertilisation to prevent more sperm entering
Haploid nucleus - has 23 chromosomes (to form a full set of chromosomes when joined with a sperm cell) and carries genetic material
Cytoplasm - has nutrients to nourish the embryo