Tech Applied Science Unit 1 Biology: Specialised Cells

Overview

• Focus on specialised cells and their roles based on structure and function.
• Important to recognize and label diagrams of these cells.

Plant Cells

Palisade Mesophyll Cells

• Location: Leaf
• Function: Photosynthesis
• Adaptations:
  • Contain many chloroplasts where photosynthesis occurs.
  • Large vacuole positions chloroplasts in outer regions for maximum sunlight exposure.
  • Thin cell walls to enable diffusion of substances.

Root Hair Cells

• Location: Roots (underground in soil)
• Function: Absorption of water and mineral nutrients.
• Adaptations:
  • Long projections (hairs) increase total surface area.
  • Lack chloroplasts as photosynthesis does not occur here.
  • Appear white due to absence of chloroplasts.

Animal Cells

Egg Cells

• Function: Carry female genetic information in haploid nucleus.
  • Human Example: 13 chromosomes from the mother.
• Structure:
  • Zona pellucida, a jelly layer, prevents multiple sperm entry.

Sperm Cells

• Function: Carry male genetic information in haploid nucleus.
  • Human Example: 13 chromosomes from the father.
• Adaptations:
  • Tail (undulipodium) for swimming to the egg.
  • Middle section packed with mitochondria for energy.

White Blood Cells

• Function: Protect against infectious diseases and foreign invaders.
• Adaptations:
  • Can change shape to squeeze through gaps to infection sites.
  • Engulf pathogens (phagocytosis).
  • Produce antitoxins and antibodies to neutralize toxins and attack pathogens.

Red Blood Cells

• Function: Transport oxygen in the bloodstream.
• Adaptations:
  • Oxygen binds with haemoglobin to form oxyhemoglobin.
  • Biconcave disc shape for large surface area.
  • Small and flexible to navigate through capillaries.