Biology · StudentHub Lesson

DNA & Genetics

How DNA stores genetic information and is passed from parents to offspring.

25 minIntermediate
01

What you will learn

  • Describe the structure of DNA
  • Explain how DNA differs from RNA
  • Define genes, alleles, and traits
  • Explain basic inheritance patterns
  • Describe the role of DNA in protein synthesis
02

Watch the lesson

DNA vs RNA (Updated) · Amoeba Sisters

Watch on YouTube
03

Topic notes

Main Idea

DNA is the molecule that stores genetic instructions, while RNA helps carry out those instructions to build proteins.

Key Concepts

  • DNA is a double helix made of nucleotides
  • Genes are segments of DNA that code for traits
  • RNA is usually single-stranded and helps make proteins

Definitions

  • Gene: a segment of DNA coding for a trait
  • Allele: a version of a gene
  • Nucleotide: building block of DNA/RNA (sugar, phosphate, base)

Processes

  1. DNA is transcribed into mRNA in the nucleus
  2. mRNA travels to ribosomes
  3. Ribosomes translate mRNA into proteins

Examples

A gene for eye color has different alleles (brown, blue) that determine the trait expressed.

Common Mistakes

  • Thinking DNA and RNA are identical
  • Confusing genes with chromosomes
  • Believing traits come from a single gene only
04

Key concepts

DNA stores genetic information as a double helixGenes are DNA segments coding for traitsRNA carries instructions from DNA to ribosomesAlleles are different versions of a geneDNA is copied and passed to offspring
05

Important terms

Gene
A segment of DNA that codes for a specific trait.
Allele
An alternative form of a gene.
Chromosome
A structure made of tightly coiled DNA.
06

Quick revision

  • DNA is a double helix
  • RNA is usually single-stranded
  • Genes code for traits
  • Alleles are gene variants
  • DNA -> RNA -> Protein
  • Chromosomes carry many genes
  • Traits pass from parents to offspring
07

Check your understanding

Question 1 · Multiple choice

What shape does DNA have?

Question 2 · Multiple choice

What molecule carries instructions from DNA to ribosomes?

Question 3 · True or false

An allele is a different version of a gene.

Question 4 · Short answer

What is a gene?

Question 5 · Short answer

Name the process of building proteins from mRNA.

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