Specialised animal cells

Specialised cells have adaptations that allow them to perform their specific roles effectively. Differentiation is the process by which a cell becomes specialised. Here are five key examples:

Sperm Cell

Function=>To swim to the egg for fertilisation.

Adaptations:

• Long tail (flagellum) – for swimming to the egg.

• Lots of mitochondria – provides energy for movement.

• Acrosome (enzyme sac) – contains enzymes to break down the egg cell membrane.

• Haploid nucleus – contains half the number of chromosomes (23).
  

Nerve Cell (Neurone)

Function=>To carry electrical impulses around the body.

Adaptations:

• Long axon – allows signals to travel long distances.

• Branched end/Dendrites – connect with other neurones forming a network.

• Myelin sheath – insulates the axon, speeds up transmission of electrical impulses.

Red Blood Cell

Function=>To carry oxygen from the lungs to tissues.

Adaptations:

• Biconcave shape – increases surface area for gas exchange.

• No nucleus – more room for haemoglobin.

• Contains haemoglobin – binds to oxygen.

• Small and flexible – fits through narrow capillaries.

Muscle Cell

Function=>To contract and relax to produce movement in the body.

Adaptations:

• Long and thin – allows muscle fibres to contract efficiently.

• Contains many mitochondria – provides lots of energy for contraction.

• Store glycogen – can be broken down into glucose and used in respiration to release energy.

• Special protein filaments (actin and myosin) – slide over each other to shorten the cell and cause contraction.

Epithelial Cell of the Small Intestine

Function=>To absorb nutrients from digested food.

Adaptations:

• Microvilli (folded cell membrane) – increase surface area for maximum absorption.

• Lots of mitochondria – to release energy for active transport.

• Lots of ribosomes – To make proteins, eg. enzymes needed for digestion.
  

Practice Question