Plant transport systems Plants have two specialised tissue: xylem and phloem which carry minerals, salts and water up and down the plant. Xylem tissue consisting of long dead cells that die and form hollow tubes. These tubes also give support to the plant. Xylem...
Photosynthesis This is the process for plants that produces their ‘food’. Also needs sunlight and chlorophyll. Plants need to respire as well as photosynthesise. Photosynthesis is their way of getting glucose (which is stored as starch) for respiration. Chloroplasts...
Osmosis Osmosis: The movement of water molecules across a partially permeable membrane from an area of higher water potential to an area of lower water potential. Osmosis is a special type of diffusion as it only involves water particles. In the context of a partially...
Clones Clones are individuals which are genetically identical. Making plant clones – bit of leaf, stem or root is planted to form a clone of the original plant – is far easier than cloning animals. Clone: These are individuals that genetically identical. Stages in the...
The Human Genome Project This is thousands of scientists collaborating to find every single human gene. Human DNA is made up of about 25,000 genes curled up to form 23 chromosomes. If the scientists work together, they can share resources and reduce costs. The...
Genetic engineering Scientists can now remove a gene from one organism and insert it into the DNA of another. This is called genetic engineering. This technique produces a genetically modified organism. Benefits of genetic engineering Reducing vitamin A deficiency...
Microscope Magnification Microscopes have improved greatly over the past 350 years. The best modern light microscopes can magnify specimens more than 1500 times. As a result, we can observe very small structures inside cells. For example, we can see inside bacterial...
Plant cells and animal cells Even though they belong to different organisms, plant and animal cells have some features in common: Cell Membrane – separates the contents of the cell and its surroundings. It controls the movement of substances like glucose, oxygen and...
The Discovery of DNA structure It was in 1962 when James Watson and Francis Crick along with Maurice Wilkins were awarded a Nobel Prize for discovering the structure of DNA. In the 1950s, in London, Rosalind Franklin and Maurice Wilkins used X-Ray photography to study...