P1: Cell Biology Flashcards
Explain how a root hair cell is specialised for its function.
-Large surface area so it can absorb large amounts of water and mineral ions.
What is the name of the smallest biological component in the human body?
An organelle
What is the largest biological component in the human body?
An organ system.
What are living organisms made up of?
Cells
Are bacteria cells bigger or smaller than animal and plant cells?
Smaller
State the components of an animal cell.
Cell membrane, ribosomes, nucleus, cytoplasm, mitochondria.
State the components of a plant cell.
Cell membrane, ribosome, nucleus, cytoplasm, mitochondria, chloroplasts, vacuole and cell wall.
Are plant and animal cells prokaryotic or eukaryotic?
Eukaryotic, meaning they have a nucleus.
What do microscopes do?
Magnify the image of a biological specimen so that it appears larger.
What are the names of the two lenses that a microscope uses to magnify something?
The eyepiece and an objective lens.
What is the eyepiece in a microscope?
The lens at the top of a compound microscope.
In a microscope, what is the objective lens?
The lens closest to the specimen.
How do you convert a millimetre to a metre?
Divide it by a thousand
State the equation linking magnification, image size and actual size.
Image size = actual size x magnification.
How do you convert a micrometre to a millimetre?
Divide it by a thousand.
How do you convert a nanometre to a micrometre?
Divide it by a thousand.
What does the coarse focus of a microscope do?
Raises the stage.
What should you place a specimen on before looking at it under a microscope?
A slide
What should you place a specimen on before looking at it under a microscope?
Electron microscope
What are the cons of electron microscopes?
Very expensive and hard to use.
What can you use electron microscopes to study?
Sub-cellular structures.
What are the names of the things the stage in a microscope has to hold the slide in place?
Clips
What is the name of the light below the stage in a microscope?
Lamp. Some microscopes have a mirror instead.
Describe how to use an optical microscope to view a prepared slide (long answer).
-Place the slide onto the stage, using the clips to hold it in place.
-Select the lowest power objective lens, and slowly turn the coarse focussing dial to position the objective lens so it almost touches the slide.
-Look through the eyepiece lens, and turn the coarse focussing dial the other way to increase the distance between the lens and slide again, to bring the object into focus
-Use the fine focusing dial to bring the cells into a clear focus.
What is the name of the microscope part that we look through?
The eyepiece
How do you calculate total magnification?
Eyepiece lens x objective lens.
What is the function of the cytoplasm?
Contains dissolved nutrients and salts. Where many of the chemical reactions happen.
What is the function of the nucleus?
Contains genetic material, including DNA, which controls the cell’s activities.
What is the function of the cell membrane?
Its structure is permeable to some substances but not to others. It therefore controls the movement of substances in and out of the cell.
What is the function of the mitochondria?
Contain the enzymes for respiration, and where most energy is released in respiration.
What is the function of the chloroplast?
Contains the green pigment, chlorophyll, which absorbs light energy for photosynthesis. Contains the enzymes needed for photosynthesis.
What is the function of the ribosome?
Protein synthesis.
What is the function of the cell wall?
Strengthens the cell and supports the plant.
What is the function of the vacuole?
Filled with cell sap to help keep the cell turgid.
Are bacterial cells eukaryotic or prokaryotic?
Prokaryotic.
How do eukaryotic cells divide?
Mitosis.
How do prokaryotic cells divide?
Binary fission.