Cells B1 Flashcards
What is the nucleus and what does it do in cells?
The nucleus contains DNA in the form of chromosomes and it controls the cell’s activities.
What is a cytoplasm and what does it do in cells?
The cytoplasm is a gel-like substance and it’s where most chemical reactions occur.
What is the mitochondria and what does it do in cells?
Mitochondria are the site of respiration and contain enzymes needed for reactions.
What is the cell membrane and what does it do in cells?
The cell membrane holds the cell together and controls what comes in and out of the cell by providing a barrier. They also contain receptor molecules that are used by hormones.
What is the cell wall and what does it do in cells?
The cell wall is made of cellulose and it provides support for the cell.
What are chloroplasts and what do they do in cells?
Chloroplasts are where photosynthesis occurs and they contain chlorophyll which makes leaves green.
What are ribosomes and what do they do in cells?
Ribosomes are the site of protein synthesis (where proteins are made).
What is the permanent vacuole and what does it do in cells?
The permanent vacuole is a large sac that contains cell sap (mixture of sugars, salts and water) to provide nutrients to the cell when it needs them.
What are 3 sub-cellular structures that are in plant cells but not in animal cells?
Chloroplasts, Cell wall and the permanent vacuole.
What type of cell is a bacteria cell?
Prokaryotic
What type of cells are plant and animal cells?
Eukaryotic
What are 3 differences between prokaryotic and eukaryotic cells?
Eukaryotic cells have nucleus’, whereas prokaryotic don’t.
Eukaryotic are multicellular whereas prokaryotic cells are unicellular.
Prokaryotic cells are much smaller than eukaryotic cells.
What are plasmids and what do they do in cells?
Plasmids carry extra genes (like antibiotic resistance) which the bacteria may need.
What is the flagella and what does it do in cells?
The flagella’s are tail like structures that allow the bacteria to propel themselves and move around.
What is the object in microscopy?
The real object or sample you’re looking at.
What is the image in magnification?
The image is the image you see when you look down the microscope.
What is magnification in microscopy?
Magnification is how many times larger the image is than the object.
What is the equation for finding magnification?
Magnification = Image Size ➗ Object Size
What are some positives of light microscopes?
Light microscopes are small, simple to use and relatively cheap.
What are some negatives of light microscopes?
Light microscopes rely on light and the resolution is limited to 0.2µm (micrometers)
What is the resolution in microscopy?
Resolution is a measure of how detailed the image is.
What are some positives to electron microscopes?
Electron microscopes use electrons instead of light, their maximum resolution is 0.1nm meaning they can see sub-cellular structures. Electron microscopes are 2000x better than light microscopes.
What are some negatives to electron microscopes?
They are very expensive and hard to use.
What is the smallest unit of measurement?
Nanometres (nm)
How many µm is 1000nm?
1µm (➗1000)
How many mm is 1900µm?
1.9mm (➗1000)
What is the eyepiece lens in microscopy?
The eyepiece lens is used to see the image and it also magnifies the image.
What is the objective lens in microscopy?
The objective lens magnifies the image. (There are usually 3 objectives lenses - x4, x10, x40)
What does the stage do in microscopy?
The stage supports the slide.
What does the clip do in microscopy?
It holds the slide in place.
What do the lamps do in microscopy?
The lamp shines light through the slide so the image can be seen more easily.
What do focusing knobs do in microscopy?
Focusing knobs move the stage up and down to bring the image into focus.
What is chromosomal DNA in bacteria cells?
Chromosomal DNA is one long circular chromosome and it controls the cells activities and replication. It floats free in the cytoplasm.
