WJEC AS Biology Biodiversity & Classification (2.1 All Organisms are related through their Evolutionary History)

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1 Name:.. Set:. Specification Points: WJEC AS Biology Biodiversity & Classification (2.1 All Organisms are related through their Evolutionary History) (a) Biodiversity is the number of different organisms on the planet. Biodiversity varies spatially and over time. (b) Biodiversity has been generated through natural selection and adaptation over millions of years. Adaptive radiation e.g. Darwin s finches on the Galapagos. (c) Organisms are classified into groups based on their evolutionary relationships. Classification places organisms into discrete and hierarchical groups with other closely related species. The need for classification and its tentative nature. Characteristic features of Kingdoms: Prokaryotae, Protoctista, Plantae, Fungi, Animalia. (d) Animal biodiversity is classified into over 20 major phyla and several minor ones with each phylum containing organisms based on a basic blueprint. Basic features of: Annelids, Arthropods, Chordates. Arthropods are subdivided into four groups (details not required). Some phyla contain many more species than others. (e) Physical features and biochemical methods can be used to assess the relatedness of organisms. DNA genetic fingerprinting and enzyme studies show relatedness without the problem of morphological convergence. (f) All organisms are named according to the Binomial system. The species concept.

2 What is biodiversity? Definition: List factors that may affect biodiversity. Where are the most biodiverse places on earth? How was biodiversity generated? Ardingly College 2 AS Biology

3 Evolutions is: Natural Selection is: Who was Charles Darwin? Where did Darwin go to develop his theory of Natural Selection? Ardingly College 3 AS Biology

4 Ardingly College 4 AS Biology

5 Why is this an example of adaptive radiation? What does the fossil record show about the historical pattern of adaptation and evolution? Ardingly College 5 AS Biology

6 Classification What is this diagram of? Ardingly College 6 AS Biology

7 What is a phylogenetic tree? What is the system of classification? K P C O F G s Ardingly College 7 AS Biology

8 Task: Find out the basic characteristics of the following taxonomic groups. Prokaryota Protoctista Plantae Fungi Animalia Ardingly College 8 AS Biology

9 The Animal kingdom is further divided into several Phyla. Annelids (8000 named species) Arthropods (1 million named species) Chordates (60,000 named species) Ardingly College 9 AS Biology

10 How do we recognise closely related species? Morphology e.g The Pentadactyl Limb Why is the presence of wings in birds and in insects not a sign of relatedness? Ardingly College 10 AS Biology

11 Biochemical methods Proportions of genes or proteins shared between species can be measured. How does this show whether species are closely related or not? Ardingly College 11 AS Biology

12 Extension: DNA Hybridisation & immunological Comparison of Proteins Immunological Comparison of Proteins Antibodies of one species will react to specific antigens on proteins within the blood serum of another. Immunological Comparison of Proteins 1. Serum albumin from Sp. A injected into Sp B 2. Sp. B produces antibodies specific to all the antigen sites on Sp. A albumin 3. Serum is extracted from Sp. B; containing antibodies specific to antigens on Sp. A s albumin. Immunological Comparison of Proteins 4. Serum from Sp. B is mixed with blood from a third species, Sp. C 5. Antibodies respond to antigens on albumin of Sp. C 6. Response is the formation of a precipitate 7. More similar antigens, more precipitate formed and more closely related the species Ardingly College 12 AS Biology

13 Binomial System of Classification What is a species? The Binomial System of Classification Uses Latin or Greek names The first name is..... o (Similar to the surname of a person) The second name is.. o (Similar to the first name of a person) The specific name is never shared with another species within the genus. Canis lupus The names are printed in italics or underlined if hand written Equus caballus The first letter of the generic name is capitalised, and the specific name is not Protea caffra Principles of Classification The grouping of species is called., whereas the practice of biological classification is called. Ardingly College 13 AS Biology

14 Problems Defining Species: The Mule Problem Which animals mate to produce a mule? How many chromosomes does a mule have? Why is this important? Ardingly College 14 AS Biology