National 5 Biology Revision

Welcome to your interactive National 5 Biology Revision site. Here you will find past papers and marking instructions, summary notes, problem solving activities and much more.

Each section has a link to BBC Bitesize, a selection of past paper questions and a youtube video.

Course Content

National 5 Biology consists of 3 units of work: Cell Biology, Multicellular Organisms and Life on Earth.

Unit One

Cell Structure

Cells are the most basic units of life. There are a few cell types you need to be able to identify and state the functions of their organelles. Below you will find links to BBC bitesize and a google document with past paper questions.

Transport Across the Cell Membrane

All cells are enclosed by a cell membrane, which is selectively permeable. Molecules can move into or out of cells by diffusion and active transport. Cells can gain or lose water by osmosis.

DNA

DNA carries the genetic information in the cells of all living organisms. It contains codes for the assembly of amino acids into all the proteins required in the body.

Proteins and Enzymes

Proteins consist of combinations of amino acids. Body proteins include structural proteins, enzymes, hormones and antibodies. The shape of an enzyme allows it to speed up a biological reaction.

Genetic Engineering

Bacteria exchange DNA using plasmids; viruses invade cells by first inserting their genetic material. Genetic engineering is the transfer of DNA between organisms using biotechnology.

Respiration

Most cell activity requires chemical energy. Respiration is the cellular process of releasing energy from food and storing it as ATP.

Unit Two

Producing New Cells

Cell division allows for growth and replacement of dead cells. Most multicellular organisms are made of different cell types that are specialised to carry out specific functions.

Control and Communication

Communication between cells in a multicellular organism occurs by use of nerve impulses or hormones. The central nervous system produces electrical impulses for rapid response.

Reproduction

New organisms are produced when male and female haploid gametes fuse. In mammals, gametes are produced in the testes or ovaries of individuals but anthers and ovaries are on the same flowering plant.

Variation and Inheritance

The phenotype for a characteristic like eye colour is the result of the combination of alleles. If the alleles in the parental genotype are dominant or recessive, probable outcomes can be predicted.

Transport in Plants

Multicellular organisms require transport systems to supply their cells and remove waste products. Plants transport substances through xylem and phloem.

Transport in Animals

Multicellular organisms require transport systems to supply their cells and remove waste products. The heart uses blood vessels to transport these substances around the body.

Absorption of Materials

Humans require transport systems to supply their cells and remove waste products. Gas exchange occurs in the lungs and food molecules are absorbed by the digestive system.

Unit Three

Ecosystems

An ecosystem is a community of animals, plants, micro-organisms, non-living things and their shared environment. Find out about energy transfer, niches and competition in ecosystems.

Sampling

Abiotic factors are non-living variables. Biotic factors are the interactions between organisms. Both affect diversity and distribution. Sampling helps us to estimate numbers of organisms in an area.

Photosynthesis

Photosynthesis is the process by which green plants use sunlight energy to make their own food. It takes place inside the chloroplasts of plant cells.

Energy

All organisms require energy. The feeding relationship in an ecosystem can be shown in a foodchain. Learn about pyramids of biomass, energy and numbers.

Food Production

A growing human population demands increased food production. Farmers try to meet that demand by intensive farming, using fertilisers and pesticides that are impacting on the environment.

Evolution

Mutations can alter the genes of individuals in a beneficial or detrimental way and introduce variety into a species.

Problem Solving

Below you will find examples of scientific literacy questions, problem solving and extended response questions.