Early scientists defined organic compounds as compounds that originate from living things. In 1828, however, the German chemist Friedrich Wohler (1800–1882) made an organic compound called urea, CO(NH2)2, out of aninorganic compound called ammonium cyanate, NH4CN. Urea is found in the urine of mammals. This was the first time in history that a compound normally […]
Atoms and Bonding
Living things are unique among all forms of matter.Unlike non-living things, all living things — from single-celled organisms such as the Euglena in Figure 1.1 to multicelled organisms such as whales and redwood trees — interact with and manipulate matter and energy. For example, all cells take in essential substances such as oxygen, water, and […]
TRANSPORT IN PLANTS AND ANIMALS
IntroductionThe movement of materials within the body tissues or between tissues in multicellular organisms like high plants and animals occurs in transport systems. In unicellular or low plants and animals, such movement is by the transport mechanisms of molecules within a transport medium by diffusion, osmosis, active transport and mass flow, among others.In multicellular animals, […]
VITAL FUNCTIONS IN ANIMALS
ANIMAL NUTRITION Nutrition in animals is heterotrophic. This means that animals feed on other living things. Animals can be classified according to their nutrition function: herbivores (plant eaters), carnivores (eat other animals), omnivores (eat animals and plants) and saprophytic (feed on decaying organic matter). In order to perform the vital function of nutrition, animals have different systems: digestive, respiratory, circulatory and excretory. Digestive system The digestive […]
VITAL FUNCTIONS IN PLANTS
Like all living things, plants can perform the three vital functions of nutrition, interaction and reproduction. PLANT NUTRITION Plants use autotrophic nutrition. In order to carry out this process, they start by taking in inorganic matter through their roots and leaves: Water and the mineral salts form the raw sap which travels to the leaves through the vessels […]
An email from a friend
Read an email about plans for the weekend to practise and improve your reading skills. Do the preparation task first. Then read the text and do the exercises. Preparation Reading text Task 1 Task 2
A Plastic Ocean: a film review
Read a review of the film ‘A Plastic Ocean’ to practise and improve your reading skills. Do the preparation task first. Then read the text and do the exercises. Preparation Reading text Task 1 Task 2
What do you do?
Preparation Exercise Transcript
Telephone numbers
Write the following telephone numbers Transcript