A Level Biology - Basic components of living systems

Explain what a microscope is and describe its function.

What does cell theory state?

List three advantages of light microscopy.

A compound light microscope has two lenses. What are they and how are they different from each other?

How does a light microscope work?

Name the 4 different ways of preparing a sample and give examples of organisms/cells that can be viewed with each technique.

Explain the benefit of having two lenses in a microscope.

Briefly describe the process of producing a dry mount sample.

Briefly describe the process of producing a wet mount sample.

Briefly describe the process of producing a squash slide sample.

Briefly describe the process of producing a smear slide.

Suggest a reason why a specimen must be thin, with reference to slide preparation.

Suggest a reason why the refractive index (ability to bend light) of the medium should be roughly the same as glass when pe preparing a wet mount.

Suggest a reason why a coverslip must be placed onto a wet mount at an angle.

Define the term 'resolution'.

Define the term 'magnification'

Suggest two things that can limit resolution

Define the term 'diffraction'

Explain why staining is used in microscopy.

Name two examples of positively charged dyes that can be used in the staining of cell components.

Explain how positively charged dyes work, in relation to staining.

Name two examples of negatively cy charged dyes that can be used in the staining of cell components.

Explain how negatively charged dyes work, in relation to staining, which is otherwise known as the negative stain technique.

State two benefits of differential staining.

Which type of cell is the gram stain technique used to separate?

Briefly describe the stages in the gram stain technique.

Suggest why Gram-negative infections are more difficult to treat than Gram-positive infections.

The acid-fast technique is another method of differential staining. Which type of cell is it used to differentiate?

Briefly describe the stages involved in the acid-fast technique.

Name and explain the 4 stages involved in the production of sample slides.

Many of the stains used in the preparation of slides are toxic or irritants. State two precautions you should take when handling these chemicals.

Name some of the rules used in the production of good scientific drawings.

State the equation used to calculate magnification.

How many nanometres (nm) is 1 micrometre?

How many micrometres (um) is 1 millimetre? (mm)

How many millimetres (mm) is 1 metre (m)

Describe what an eyepiece graticule is, and explain its function.

Describe what a stage micrometer is and state the actual size of each division.

State the formula used to find 1 graticule division.

Define the term 'contrast'.

Describe what electron microscopy is and explain its uses.

State three disadvantages of using electron microscopes.

Name the two types of electron microscope.

Explain how a transmission electron microscope works.

Explain how a scanning electron microscope works (SEM).

Explain the importance of the production of a three-dimensional image from a scanning electron microscope.

Suggest a reason for fixation, in relation to the preparation of samples in electron microscopy.

Suggest a reason for dehydration, in relation to the preparation of samples in electron microscopy.

Suggest a reason for the embedding of the sample in resin, in relation to the preparation of samples in electron microscopy.

Suggest a reason for staining with heavy metals, in relation to the preparation of samples in electron microscopy.

State 5 differences between light and electron microscopy.

Define the term 'artefact', giving one example.

State an example of a structure in a cell that is now known to scientists as an 'artefact'.

Define the term 'fluorescence'.

Explain how a laser scanning confocal microscope works.

State why lasers are used to provide illumination in laser confocal microscopy.

Explain why you would see more detail wit an electron microscope than with a light microscope.

Explain the purpose of pinhole aperture in confocal microscopy.

List 5 advantages of laser scanning confocal microscopy.

Name an example of a fluorescent tag.

Explain how GFP can be used to study the production and distribution of proteins in cells and organisms.

Name the two types of cells, and give examples of organisms in each type.

Describe what a prokaryote is.

Describe what a eukaryote is.

Define the term 'metabolism'

What are organelles?

State two functions of membranes.

Draw a typical animal cell

Describe what a 'nucleus' is and its function.

Describe what a 'nuclear envelope' is and its function.

Explain why DNA cannot leave the nucleus and explain how it can be transported out.

Explain how chromosomes are formed.

What is the nucleolus?

State two functions of RNA.

Describe what 'mitochondria' are and explain its function.

Describe the structure of mitochondria.

Describe what a 'vesicle' is, and its function.

Describe what a lysosome is.

State three functions of lysosomes.

What is the cytoskeleton?

State three functions of the cytoskeleton.

Name the three components that make up the cytoskeleton.

Describe the structure of microfilaments, and explain its function.

escribe the structure of microtubules and explain its function.

Microtubules also make up a structure that has a role in the physical segregation of chromosomes in cell division. Name this structure

Explain the function of intermediate fibres.

Explain why the membrane that surrounds the lysosome is so important.

Define the term 'compartmentalisation;.

Explain why cells need to be compartmentalized and describe three examples of compartmentalization within an animal cell.

What are centrioles, and what are their function?

Describe what flagella are, and explain their function.

Describe what cilia are, and explain its function.

Name the two types of cilia, where they can be found and their functions.

Name the three primary organelles responsible for protein synthesis

Describe what the endoplasmic reticulum is, and name the two types and their functions.

Describe what ribosomes are and explain their function.

Describe the structure of the golgi apparatus, and explain its function

What is the difference between the proteins that are packaged into secretory vesicles and lysosomes?

Describe the stages involved in protein synthesis.

Define the term 'exocytosis'.

Describe the structure and function of cell walls found in plants.

Draw a typical plant cell.

Describe the structure and function of a vacuole.

Describe the structure of a chloroplast

Explain the importance of the internal membranes, in relation to photosynthesis.

Explain what is meant by the term 'extremophile', and name some examples of some that still exist today.

To which domain do extremophiles belon to?

Define the term 'cell ultrastructure'

Describe the characteristics making up prokaryotic cells.

Describe the characteristics making up eukaryotic cells.

Suggest why the lack of membrane-bound organelles does not stop prokaryotic cells from making proteins.

Human genomes contain many more genes than bacterial genomes, and they are much longer.

Discuss the way in which this affects the packing of DNA in eukaryotes and prokaryotes.

What is the endosymbiotic theory?

State any evidence that supports the endosymbiotic theory.

Give three functions of plant cell walls.

State similarities and differences between a human cell and a plant root cell.