Specialized Cell Types

This section examines several types of specialized cells and their adaptations for specific functions.

Palisade Cell

Palisade cells are specialized plant cells found in leaves.

Function: Carry out photosynthesis at the top of a leaf

Adaptations:

• Large surface area to maximize light absorption

Ciliated Cell

Ciliated cells are found in the respiratory tract.

Function: Sweep mucus containing trapped dust and germs

Adaptations:

• Thin layer of hair-like projections called cilia on the cell surface

Root Hair Cell

Root hair cells are specialized plant cells found in roots.

Function: Absorption of water and mineral ions from soil

Adaptations:

• Finger-like projections to increase surface area for absorption
• Large permanent vacuole to speed up water movement by osmosis
• Mitochondria for active transport of mineral ions

Example: Root hair cells lack chloroplasts since they are underground where there is no light for photosynthesis.

Bacterial Cell

The guide provides a labeled diagram of a bacterial cell, highlighting its prokaryotic structure.

Highlight: Bacterial cells lack a nucleus and instead contain chromosomal DNA and plasmids with genes.

Key features of bacterial cells include:

• Cell membrane
• Cell wall
• Capsule
• Flagellum
• Chromosomal DNA
• Plasmid DNA

This section effectively illustrates the 10 difference between prokaryotic and eukaryotic cell structure through the comparison of bacterial and plant/animal cells.

Specialized Animal Cells

This section focuses on highly specialized animal cell types and their adaptations.

Nerve Cell (Neuron)

Nerve cells have a distinctive elongated structure for coordinating information between the brain, spinal cord, and body.

Function: Transport electrical signals to the brain

Adaptations:

• Multiple dendrites for connections to other nerve cells
• Long axon to carry nerve impulses over distances
• Nerve endings (synapses) with abundant mitochondria for energy production

Definition: Neurons are specialized cells of the nervous system that transmit electrical and chemical signals.

Sperm Cell

Sperm cells are highly specialized for reproduction.

Function: Pass on the father's genes during fertilization

Adaptations:

• Streamlined shape for efficient movement
• Tail (flagellum) for propulsion to swim towards the egg
• Acrosome in the head containing enzymes to penetrate the egg
• Mid-piece packed with mitochondria to provide energy for movement

Highlight: The unique structure of sperm cells demonstrates how specialized animal cells and their functions are closely related to their specific roles in the body.