Biology Chapter on Observation and Systems

Study Notes

Observation and Inference

Observation: Using the senses or a measuring device to gather information. Example: A footprint in the sand had four claw marks.
Inference: A conclusion based on an observation. Example: An animal had been on the sand.

Pellagra

Pellagra was a disease caused by a lack of niacin (vitamin B) in the diet.

Levels of Organization

Cells form tissues.
Tissues form organs.
Organs form organ systems.
Organ systems form an organism.

Digestive System

Function: Absorb nutrients needed by all body cells.
Mechanical breakdown (teeth, tongue): Increases speed of chemical breakdown.
Teeth: Primarily responsible for mechanical breakdown.
Chemical digestion: Mainly occurs with acids in the stomach and intestines.
Both mechanical and chemical breakdown are needed for nutrient absorption.
Large intestine: An organ in the digestive system.
Average small intestine length: 15-18 feet.
Path: Mouth > esophagus > stomach > small intestine > large intestine > rectum.

Nervous System

Function: Senses the external world, controls the body, and allows communication between body systems.
Parts: Brain (3 lbs), spinal cord, nerves (sensory and motor).
Sensory nerves: More concentrated in fingers than palm/forearm.

Respiratory System

Function: Takes in oxygen and releases carbon dioxide (waste).
Inhalation: Lungs expand (inflate).
Exhalation: Lungs shrink (deflate).
Diaphragm: Muscle that contracts during inhalation and relaxes during exhalation.
Main Structures: Nose, mouth, trachea, lungs, bronchi, bronchioles, alveoli.

Circulatory System

Function: Transports oxygen, nutrients, and waste throughout the body.
Nutrients: Transported by blood, needed by all cells and absorbed in the small intestine.
Capillaries: Deliver oxygen and nutrients to cells.
Oxygen transfer: From blood to organs through capillary walls.
Heart: Pumps blood throughout the body.
Arteries: Carry blood away from the heart.
Veins: Carry blood toward the heart.
Valves: Prevent blood from flowing backward.
Pulse: Heartbeats per unit of time.
Normal resting pulse: 60-80 beats per minute.
Exercise effect on pulse: Increases after exercise; decreases after regular exercise.

Skeletal and Muscular Systems

Bones at birth vs. adulthood: More at birth, some fuse.
Adult bones: 206.
Bone growth: Continues until about age 20.
Bone distribution: More than half in hands and feet.
Tendons: Attach muscles to bones.
Ligaments: Connect bones for stability.
Skull: Cranium; protects the brain.
Ribs: Protect the heart and lungs.
Vertebrae: Protect the spinal cord (a bundle of nerves).
Smallest bones: Hammer, anvil, stirrup (in ears).
Longest/strongest bone: Femur (thighbone).
Hardest substance: Enamel (teeth).
Cartilage: Flexible, sturdy tissue (ears, nose).
Red blood cell production: Marrow in long bones.

Description

Explore key concepts from biology, including observation vs. inference, the levels of organization within living organisms, and the intricacies of the digestive system. This quiz will test your understanding of how various biological processes function and interconnect.