Surface Area to Volume Ratio

Learn. The surface area to volume ratio (SA:V) is one of the underlying themes throughout biology. It explains why cells are as small as they are, why we developed systems to deliver food and oxygen to our cells, why some animals are large and thin whilst others are fat and small. The process of diffusionContinue reading “Surface Area to Volume Ratio”

Sample Trial Paper – Difficulty: Hard

Multiple choice (20 marks) 1. What is the IUPAC name of the following compound? (A) 1,3-dichloro-2-fluoro-2,3-dibromopropane (B) 1,2-dibromo-2-fluoro-1, 3- dichloropropane (C) 1,2-dibromo-1,3-dichloro-2-fluoropropane (D) 2,3-dibromo-1,3-dichloro-2-fluoropropane 2. Ethanol is often called a “universal solvent” since it can dissolve both polar and nonpolar solutes. Which property of ethanol makes it a suitable solvent for both organic and inorganicContinue reading “Sample Trial Paper – Difficulty: Hard”

The theory of evolution by natural selection

Explain biological diversity in terms of the Theory of Evolution by Natural Selection by examining the changes in and diversification of life since it first appeared on the Earth. Learn. Biological diversity Bio refers to life and diversity refers to difference. Therefore, biodiversity is a term which describes the difference in the genetic makeup inContinue reading “The theory of evolution by natural selection”

Ecosystem Pressures part 1

Predict the effects of selection pressures on organisms in ecosystems by examining. Biotic factors Abiotic factors Learn. Ecosytems are made up of both biotic factors and abiotic factors. Biotic factors are factors which relate to living things, where as, abiotic factors are related to non living things in an ecosystem. An ecosystem is a communityContinue reading “Ecosystem Pressures part 1”