ArticleslgStudy

biology

SEMA4G

SEMA4G 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 SEMA4G rather than just read about it. In short: Semaphorin-4G is a protein in humans encoded by the SEMA4G gene. Semaphorins are a large family of conserved, secreted and membrane associated proteins which possess a semaphoring (Sema) domain and a PSI domain (found in plexins, semaphorins and integrins) in the N-terminal extracellular portion.

SEMA4G — main illustration
SEMA4G — illustration

Key takeaways

  • SEMA4G belongs to biology; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect SEMA4G to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of SEMA4G from memory before moving on to harder problems.

Reference excerpt

Semaphorin-4G is a protein in humans encoded by the SEMA4G gene. Semaphorins are a large family of conserved, secreted and membrane associated proteins which possess a semaphoring (Sema) domain and a PSI domain (found in plexins, semaphorins and integrins) in the N-terminal extracellular portion. Semaphorins maintain cell motility and attachment in axon guidance, immune cell maintenance, vascular growth and tumour movement. Based on sequence and structural similarities, semaphorins are put into eight classes: invertebrates contain classes 1 and 2, viruses have class V, and vertebrates contain classes 3-7. Semaphorins serve as axon guidance ligands via multimeric receptor complexes, some (if not all) containing plexin proteins. This gene encodes a class 4 semaphorin. This gene and the gene for mitochondrial ribosomal protein L43 overlap at map location 10q24.31 and are transcribed in opposite directions.

References

Further reading

Illustrations

SEMA4G illustration
SEMA4G illustration
SEMA4G illustration
SEMA4G illustration
SEMA4G illustration

Worked examples

Example 1 — a first encounter with SEMA4G

Start with the simplest possible case. Write down what SEMA4G 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 SEMA4G 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 SEMA4G 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 SEMA4G

In research
SEMA4G 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 SEMA4G 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
SEMA4G is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genes on human chromosome 10, Human chromosome 10 gene stubs, so understanding it makes those chapters shorter.
In everyday life
Look for SEMA4G 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.
Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “SEMA4G” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study SEMA4G in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what SEMA4G means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain SEMA4G out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SEMA4G in simple terms?

Semaphorin-4G is a protein in humans encoded by the SEMA4G gene. Semaphorins are a large family of conserved, secreted and membrane associated proteins which possess a semaphoring (Sema) domain and a PSI domain (found in plexins, semaphorins and integrins) in the N-terminal extracellular portion.

Why does SEMA4G 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 SEMA4G?

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 SEMA4G.

Tags

  • Genes on human chromosome 10
  • Human chromosome 10 gene stubs

Keep exploring