Biology Chapter on Specialized Cells

Animal and plant cells differentiate to form specialized cell types.
Most animal cells differentiate early in development; plant cells can differentiate throughout their life.
Sperm Cell: Tail for swimming; high energy from mitochondria aids movement.
Red Blood Cell: Lacks a nucleus, enhancing oxygen transport; contains haemoglobin and has a flat bi-concave shape for improved surface area.
Muscle Cell: Features protein fibers for contraction and has numerous mitochondria for energy.

Diffusion: Passive movement of particles from high to low concentration; occurs in nutrients, oxygen, and waste removal.
Osmosis: Passive diffusion of water from an area of low solute concentration to high concentration through a semi-permeable membrane.
Active Transport: Energy-requiring process for moving substances from low to high concentration; essential for sugar and mineral ion absorption.

Single-celled organisms utilize large surface area-to-volume ratios for efficient transport.
Multicellular organisms have folded membranes and good blood supply for efficient exchange.
Villi in Small Intestine: Increase nutrient absorption area; thin walls facilitate diffusion.
Fish Gills: Composed of thin filaments with capillaries for enhanced gas exchange.

Stem cells can develop into various specialized cells; can be adult or embryonic stems.
Adult Stem Cells: Found in specific body regions; have fewer ethical issues and safe usage; limited differentiation.
Embryonic Stem Cells: Can differentiate into any cell type; risks include ethical concerns and potential for infection.
Plant Meristem: Found in roots/shoots; can form all cell types, enabling cloning of plants with desirable traits.

Involves creating a cloned embryonic stage from a patient’s cells; reduces rejection risk in transplants.

Chromosomes: Found in the nucleus, containing numerous genes.
Body cells undergo mitosis in a three-stage cell cycle, resulting in two identical daughter cells.
Mitosis is crucial for growth, repair, and asexual reproduction.

Arteries: Thick, muscular walls; high pressure; carry blood away from the heart.
Veins: Thinner walls; larger lumen; carry blood to the heart; often contain valves.
Capillaries: One-cell-thick for easy nutrient and gas exchange between blood and tissues.

Composed of cardiac muscle; essential for blood circulation.
Right side pumps deoxygenated blood to lungs; left side pumps oxygenated blood to the body.
Controlled by electrical impulses; artificial pacemakers may regulate heartbeat.

Characterized by two circuits: one for lungs and another for the rest of the body, enhancing oxygen delivery.

Pathogens: Including bacteria, viruses, fungi, and protists; spread through air and water, sometimes directly via contact.
Bacteria: Can produce toxins, quickly reproduce, and cause various illnesses.
Viruses: Require host cells for replication; can cause severe conditions like HIV/AIDS.

Hygiene practices such as hand washing and disinfecting surfaces help prevent disease spread.### Disease Control Methods
Isolation of infected individuals (people, animals, and plants) helps to prevent disease spread.
Controlling vector populations, such as mosquitoes for malaria, limits disease transmission.
Vaccination introduces inactive or dead pathogens to trigger antibody production by lymphocytes.

Vaccination of a large percentage of the population reduces disease transmission, benefiting even unvaccinated individuals.

Herd immunity: Community protection achieved when a significant portion is vaccinated.
Pathogen: Microorganism (bacterium, virus) responsible for causing disease.
Protist: Eukaryotic organisms not classified as animals, plants, or fungi, including algae and protozoa.
Sexually transmitted disease (STD): Illnesses spread through sexual contact.
Toxin: Poisonous substance produced by organisms like bacteria or fungi.
Vaccination: Process of introducing weakened pathogens to stimulate an immune response.
Vector: Organisms (e.g., mosquitoes) that transfer diseases between hosts.
Virus: Infectious agents that replicate within living host cells.

Definition: Loss of water through stomata leads to evaporation, creating a transpiration stream that pulls water up from roots via xylem.
Functions of transpiration:
- Maintains turgor pressure in plant cells.
- Supplies water necessary for photosynthesis.
- Aids in transporting mineral ions to leaves.
Xylem structure: One-way vessels made from dead cells with lignified walls, facilitating water and minerals transport.

Involves the movement of dissolved sugars from leaves (produced during photosynthesis) to various plant parts.
Supports plant processes like respiration, growth, and glucose storage.

Temperature: Higher temperatures accelerate transpiration due to increased evaporation rates.
Humidity: Lower humidity levels enhance transpiration because of a steeper concentration gradient of water vapor between the air and plant.