IGCSE Biology Notes

Flashcards about IGCSE Biology notes. This set covers topics from characteristics of living things to the nervous system and the eye.

What are the seven functions of living things?

Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition

What is sensitivity in the context of living things?

The ability to detect and respond to a stimulus.

What is excretion?

Removal of harmful products of metabolism.

What is autotrophic nutrition?

Organisms that make their own food, such as plants.

What is the order of classification of organisms from broadest to most specific?

Kingdom, Phylum, Class, Order, Families, Genus, Species

What is a species?

A group of organisms that share similar appearances and can breed with each other.

What are the five kingdoms of living things?

Bacteria, Protoctista, Fungi, Plants, and Animals.

How do bacteria reproduce?

Asexual reproduction by binary fission.

What is the cell wall of fungi made of?

Cell wall made of chitin.

What are the divisions of the plant kingdom?

Algae, ferns, mosses, and seed plants.

What are the main groups of invertebrates?

Nematodes, Annelids, Molluscs, and Arthropods.

What are the divisions of arthropods?

Insects, crustaceans, and arachnids.

What are the characteristics of fish?

Body covered in moist scales, fins for swimming, and gills for gas exchange.

What are the characteristics of amphibians?

Moist, smooth, and non-scaly skin; young live in water, adults on land.

What are the characteristics of reptiles?

Covered in dry, scaly skin.

What are the characteristics of mammals?

Body covered in hair, produce milk, have external ear pinna.

What structures are present in plant cells but absent in animal cells?

Cell wall, chloroplast, vacuole.

What is the cell wall?

Non-living structure made of cellulose that supports the plant cell.

What is cytoplasm?

Jelly-like substance where most chemical reactions happen.

What is the nucleus?

Contains DNA and controls the activities of the cell.

What is the function of mitochondria?

Site of aerobic respiration.

What is the specialization of root hair cells?

Have long hairs to increase surface area for water and mineral absorption.

What is the specialization of xylem vessels?

Transport water and minerals, made of dead cells forming long, hollow tubes.

What is the specialization of phloem cells?

Transport sugar and amino acids, have perforated cell walls for communication.

What is the specialization of red blood cells?

Transport oxygen, have no nucleus, contain hemoglobin.

What is the specialization of nerve cells?

Conduct electrical impulses to and from the brain, have a layer of fat for insulation.

What is the specialization of white blood cells?

Get rid of bacteria and viruses, can change shape to penetrate blood vessels.

What are the characteristics of enzymes?

Enzymes which speed up reactions, are specific to one reaction, and are sensitive to temperature and pH.

What are the main food classes?

Protein, fats, carbohydrates, vitamins, minerals, fibers, water

What elements make up carbohydrates?

Carbon, hydrogen, and oxygen.

What elements make up proteins?

Carbon, hydrogen, nitrogen, and sometimes sulphur.

What is ingestion?

Taking food into a living organism.

What is digestion?

Breaking down large insoluble food molecules into small soluble ones.

What is absorption?

The process by which food molecules enter the blood stream.

What is peristalsis?

Rhythmic contractions of the oesophagus to push food to the stomach.

What is pepsin?

An enzyme that breaks proteins down into shorter chains (polypeptides).

What is the role of hydrogen carbonate ions?

Neutralize the stomach acid in the small intestine.

What is the function of villi?

Increases the surface area for absorption in the ileum.

What are the major divisions within the plant kingdom?

The plant kingdom is divided into algae, ferns, mosses, and seed plants

What is the equation for photosynthesis?

Carbon dioxide + water = glucose + oxygen

What is the function of palisade layer cells in a leaf?

Contain the most chloroplasts for photosynthesis to take place

What factors affect the rate of transpiration?

Water availability, surface area of the leaf, humidity

Why do plants need nitrogen?

To make proteins

What are the deficiency symptoms if a plant lacks nitrogen?

Poor growth and yellow leaves

What is the transport system in plants?

Vascular bundles (xylem and phloem).

What are the characteristics of xylem vessels?

They have very hard and waterproof walls

What are the characteristics of phloem tubes

They are filled with cytoplasm, though they have no nucleus

What is the order of blood vessels, starting from the heart and returning back to the heart?

Arteries, arterioles, capillaries, venules, veins

What are the reasons for Coronary Heart Disease (CHD)?

Inheritance, Fatty diet, Smoking

Why is carbon monoxide dangerous?

This gas binds irreversibly to the haemoglobin in red blood cells preventing them from carrying oxygen

What are the three components of the skin associated with temperature maintenance?

Contains sweat glands, hair and blood vessels

List three major structures of the eye.

Sclera, Choroid, Retina