Use the above link to study topics in this Unit Use the below link for review and some aniamtions

5.1 Topics in Ecology and Evolution

.1 Communities and Ecosystems, see below;

.2 The Greenhouse Effect;

.3 Populations ;

.4 Evolution;

.5 Classification

.1 Communities and ecosystems:

Use the above link to review definitions and concepts for topic

5.1 Food chains Food Webs

external image fodchain.jpg external image Food_Web3.gif external image g_me_wiae_2.gif external image food%20chain.jpg

Energy Pyramids

external image Energy-Pyramid.jpg external image dec-py.gif


RICE: Genus and species (binomial nomenclature)

Rice is an annual grass typically growing 1-1.8 m tall. Shorter, higher yielding ‘semi-dwarf’ varieties were introduced during the ‘Green Revolution’ in the 1960s.

The main species of cultivated rice is Oryza sativa. It is one of 23 species in the genus Oryza. Plants in this genus are tolerant to desert, hot, humid, flooded, dry and cool conditions, and grow in saline, alkaline and acidic soils. Oryza sativa originated in the humid tropics of Asia. One other member of the genus Oryza glaberrima, from West Africa, is the only other cultivated rice species. Asian rice has evolved into three eco-geographic races - indica, japonica and javanica.
Within each of these races are distinctive varieties of rice which can be classified by their grain shape and texture. Long grain rices are typically of the indica race and include the fragrant Jasmine rice from Thailand and Basmati rice from India. Short grain rice, typically japonica, is usually more sticky than long grain and is favoured in Japan. Saki rice is grown in Japan to make rice wine, and in Indonesia there are red and black grained varieties. ‘Golden Rice’ is a new type of variety being developed which is genetically modified to produce more beta carotene which is needed in the diet as a precursor to viatmin A. In some regions of SE Asia and Africa vitamin A deficiency is a serious problem, responsible for over a million deaths and
half amillion cases of blindness each year.

external image rice.gif