Biology Lecture Notes

These flashcards cover key vocabulary and concepts from biology, focusing on cellular biology, human anatomy and physiology.

Cell

The basic unit of life; all living things are made of cells.

Nucleus

Controls the cell and contains DNA.

Cell membrane

Controls what enters and exits the cell.

Cytoplasm

Jelly-like fluid where chemical reactions happen.

Mitochondria

Releases energy for the cell.

Organelles found only in plant cells

Cell wall, chloroplasts, and a large vacuole.

Chloroplasts

Site of photosynthesis.

Magnification

Eyepiece lens × objective lens.

Respiratory system

To bring oxygen into the body and remove carbon dioxide.

Trachea

Carries air to the lungs.

Bronchi

Two tubes that lead into each lung.

Bronchioles

Smaller air tubes inside the lungs.

Alveoli

Tiny air sacs where gas exchange occurs.

Gas exchange

Oxygen enters the blood and carbon dioxide leaves the blood.

Diaphragm during inhalation

Contracts and moves down.

Diaphragm during exhalation

Relaxes and moves up.

Digestive system

To break down food into small molecules the body can absorb.

Mechanical digestion

Physical breakdown of food (chewing, stomach churning).

Chemical digestion

Enzymes breaking food into smaller molecules.

Oesophagus

Pushes food from the mouth to the stomach.

Stomach function

Acid and enzymes break down proteins.

Small intestine

Absorbs nutrients into the bloodstream.

Large intestine

Absorbs water.

Liver function

Produces bile to break down fats.

Pancreas function

Releases digestive enzymes.

Villi

Tiny structures in the small intestine that increase surface area for absorption.

Circulatory system

To transport oxygen, nutrients, and waste around the body.

Heart chambers

Four: right atrium, right ventricle, left atrium, left ventricle.

Oxygenated blood

Pumped by the left side of the heart.

Deoxygenated blood

Pumped by the right side of the heart.

Arteries

Carry blood away from the heart.

Veins

Carry blood to the heart and contain valves.

Capillaries

Tiny blood vessels where gas and nutrient exchange occurs.

Red blood cells function

Carry oxygen using haemoglobin.

White blood cells function

Fight infection.

Platelets function

Help blood clot.

Plasma

The liquid part of blood that carries nutrients and waste.