Chromosomes, Genes & Proteins - Cambridge (CIE) IGCSE Co-ordinated Sciences

Overview

• Chromosomes: Thread-like structures in the nucleus made of DNA, carrying genetic information in genes.
• Genes: Short lengths of DNA on chromosomes that code for specific proteins (e.g., collagen, enzymes, hormones).
• Alleles: Alternative forms of genes that give characteristics, such as eye color (blue, green, brown).

Detailed Concepts

Chromosomes

• Located in the nucleus of cells.
• Composed of DNA.
• Carry genetic information crucial for heredity.

Genes

• Code for proteins that determine traits and physiological functions.
• Found on chromosomes.
• Can exist in different forms, known as alleles.

Proteins

• Structural proteins like collagen help build body structures.
• Enzymes facilitate biochemical reactions.
• Hormones regulate physiological activities.

Alleles

• Variants of a gene.
• Responsible for the diversity in physical attributes among organisms.

Visualizing Genes in Cells

• Use a "Zoom" model to visualize the cell structure:
  • Zoom out to see the whole organism.
  • Zoom into cell nucleus to see chromosomes.
  • Further zoom to visualize genes and DNA bases.

Study Tips

• Understanding the position and role of chromosomes and genes is key in studying cell biology and inheritance.
• Relate protein functions to their genetic codes to understand physiological traits.

Additional Resources

• Interactive study tools like flashcards and mock exams can reinforce understanding of these concepts.
• Review diagrams showing the relationship between DNA, genes, and chromosomes for a spatial understanding.