biology

HIS-selective medium

HIS-selective medium is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand HIS-selective medium rather than just read about it. In short: HIS-selective medium is a type cell culture medium that lacks the amino acid histidine. It can be used with bacteria reliant on the expression of a gene encoding proteins involved in histidine expression in order to survive.

Key takeaways

HIS-selective medium belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect HIS-selective medium to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HIS-selective medium from memory before moving on to harder problems.

Reference excerpt

HIS-selective medium is a type cell culture medium that lacks the amino acid histidine. It can be used with bacteria reliant on the expression of a gene encoding proteins involved in histidine expression in order to survive. Only bacteria expressing such genes (such as hisB in Escherichia coli and HIS3 in Saccharomyces cerevisiae) will survive on these media.

References

Worked examples

Example 1 — a first encounter with HIS-selective medium

Start with the simplest possible case. Write down what HIS-selective medium claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to HIS-selective medium before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about HIS-selective medium ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of HIS-selective medium

In research: HIS-selective medium appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses HIS-selective medium in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: HIS-selective medium is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cell culture media, Microbiological media, Microbiology stubs, so understanding it makes those chapters shorter.
In everyday life: Look for HIS-selective medium outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study HIS-selective medium in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HIS-selective medium means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain HIS-selective medium out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HIS-selective medium in simple terms?

Why does HIS-selective medium matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study HIS-selective medium?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on HIS-selective medium.