IGCSE Edexcel Biology (9-1) Topics 1 - 3

IGCSE Edexcel Biology (9-1) Topics 1 - 3

What do the initials MRS C GREN stand for?

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

Name the five kingdoms into which all living things can be classified.

Animals, plants, fungi, protoctists, and bacteria

What are the common features of eukaryotic organisms?

Plants, animals, fungi, and protoctists.

What are the common features of prokaryotic organisms?

Bacteria

What is a pathogen?

An organism that causes disease.

What are the levels of organization in organisms?

Organelles, cells, tissues, organs, and systems

What is the function of the nucleus?

Contains the genetic information of the cell and controls the activities of the cell.

What is the function of the cell membrane?

Acts as a boundary between the cytoplasm and the outside of the cell, controlling what comes in and out.

What is the function of the cytoplasm?

Contains organelles and enzymes, where many of the cell’s chemical reactions take place.

What is the function of mitochondria?

Carry out aerobic respiration, releasing energy for the cell.

What is the function of ribosomes?

Make proteins (protein synthesis), determined by the genes in the nucleus.

What is the function of chloroplasts?

Contain chlorophyll and absorb light energy to make food in photosynthesis.

What is the function of the cell wall?

Protects the cell, keeps its shape, and is freely permeable.

What is the function of the vacuole?

Filled with cell sap and stores dissolved sugars, mineral ions, and water, helping keep the cell’s shape.

What is cell differentiation?

The process by which a cell changes to become specialized.

What are stem cells?

Undifferentiated cells that have the ability to become specialized.

Name the chemical elements present in carbohydrates, proteins, and lipids.

Carbohydrates: Carbon, hydrogen, oxygen. Proteins: Carbon, hydrogen, oxygen, nitrogen. Lipids: Carbon, hydrogen, oxygen.

What are the building blocks of carbohydrates, proteins, and lipids?

Carbohydrates: simple sugars. Proteins: amino acids,. Lipids: fatty acids and glycerol.

What is the role of enzymes in metabolic reactions?

Act as biological catalysts, speeding up reactions without being used up.

Name three ways by which cells move substances into and out.

Diffusion, Active Transport, and Osmosis

What is diffusion?

The net movement of particles from a region of high concentration to a region of low concentration.

How does temperature affect the rate of diffusion?

At a higher temperature, particles have more kinetic energy and move faster, increasing the diffusion rate.

What is osmosis?

The movement of water from a dilute solution to a more concentrated solution across a partially permeable cell membrane.

What is active transport?

The process of moving substances against a concentration gradient, requiring energy released from respiration.

What is photosynthesis?

The process by which green plants turn energy from sunlight into chemical energy (sugars).

What is the balanced chemical symbol equation for photosynthesis?

6CO2 + 6H2O → C6H12O6 + 6O2 (sunlight chlorophyll)

Name two minerals that plants require for photosynthesis.

Nitrates and Magnesium.