What are laboratory apparatus .

Laboratory apparatus are the tools required to complete lab work, including test tubes, pipettes, beakers, and graduated cylinders.

Explanation:

The laboratory apparatus depends upon the type of laboratory you are in and the experiment you are going to perform.

For example, if you are in a chemistry laboratory, the common apparatus you need to use are:

Test tube holders, tongs - for holding test tubes and beakers that should not or cannot be touched.

Test tubes - for holding small samples or for containing small-scale reactions.

Test tube stands - for keeping a few test tubes upright

Droppers - for adding a very small amount of liquid, drop by drop

Burettes - for adding a precise volume of a liquid

Pipettes - to dispense small and precise amount of liquid samples

Bunsen burners, hot plates, hot water baths - heat sources

Beakers, Erlenmeyer flasks - to contain reactions or to hold liquid samples

Watch glasses - a cover for beakers; sometimes used as an evaporating dish

Funnels - for funneling or for filtering

Graduated cylinders - to measure an amount of liquid

Volumetric flasks - to make precise dilutions

Wash bottles - for dispensing small quantities of distilled water

Wire gauges, clay triangles - to support a container while it is heating

Clamp stands - to support a piece of equipment or a part of it that is otherwise unstable

Balances - to measure the mass of a reagent or product

Kipp's apparatus - to produce a reagent gas (e.g. H2S) in a controlled manner

Spectrophotometers - to measure the absorbance and transmittance of a liquid sample

Fume hoods - to ventilate harmful gases

Desiccators - to preserve a substance in a moisture-free environment

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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enzyme speed up the reactions