Faculty of Science, School of Sciences, Natabua Campus Lautoka. BIO509: Botany Introductory Lecture: The Classification of Plants and Other Organisms

Transcription

1 Faculty of Science, School of Sciences, Natabua Campus Lautoka BIO509: Botany Introductory Lecture: The Classification of Plants and Other Organisms

2 LECTURER AND COURSE COORDINATOR Professor Anand Tyagi Phone: Ext 7020

3 LEARNING OBJECTIVE 1 Define taxonomy Explain why the assignment of a scientific name to each species is important for biologists

4 KEY TERMS TAXONOMY Science of describing, naming, and classifying organisms

5 Describing Plants

6 Scientific Names Biologists use scientific names to precisely identify organisms Each organism has only one scientific name Avoids confusion of many common names

7 LEARNING OBJECTIVE 2 Identify the biologist who originated the binomial system of nomenclature Describe the general scheme of the system

8 KEY TERMS BINOMIAL NOMENCLATURE System for giving each organism a two-word scientific name First used consistently by Carolus Linnaeus

9 Linnaeus

10 Binomial Nomenclature Species The basic unit of classification The scientific name of each species has two parts: generic name (genus) specific epithet

11 Tradescantia virginiana

12 Species and Subspecies A species is commonly defined as the largest group within which interbreeding produces viable offspring. A sub-species is a subgroup below the level of a species. One definition is a group which can interbreed successfully with other subspecies, but does not do so in practice (e.g. due to geographical isolation).

13 Gilia latiflora Gilia tenuiflora subsp. excellens subsp. davyi subsp. latiflora Fig. 18-4, p. 355

14 LEARNING OBJECTIVE 3 List and describe the hierarchical groupings of classification

15 Classification Hierarchical groups (most to least inclusive) domain kingdom phylum class order family genus species

16 Classification of Ginger

17 Domain Kingdom Phylum Class Order Family Genus Eukarya Plantae Anthophyta Monocotyledones Zingiberales Zingiberaceae Zingiber (ginger genus) 5 other kingdoms 9 other phyla 1 other main class 18 other orders 4 other families 48 other genera Each taxonomic level is more inclusive than the one below it. For example, the order Zingiberales consists of 5 families. The family Zingiberaceae contains 49 genera and a total of about 1300 species.

18 A Dichotomous Key A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers. Keys consist of a series of choices that lead the user to the correct name of a given item.

19

20

21 LEARNING OBJECTIVE 4 Define systematics Describe the cladistic approach to systematics

22 KEY TERMS SYSTEMATICS Scientific study of the diversity of organisms and their natural (evolutionary) relationships A systematist seeks to reconstruct phylogeny

23 KEY TERMS PHYLOGENY Evolutionary history of a species or other taxonomic group MONOPHYLETIC Said of a group consisting of organisms that evolved from a common ancestor

24 KEY TERMS CLADISTICS Classification of organisms based on recency of common ancestry rather than degree of structural similarity

25 Cladistics Cladists emphasize phylogeny by focusing on when evolutionary lineages (lines of descent) divide into two branches Cladists develop cladograms

26 KEY TERMS CLADOGRAM A diagram that illustrates evolutionary relationships based on the principles of cladistics

27 Building a Cladogram

28 Characters TAXON VASCULAR TISSUES SEEDS FLOWERS Moss A A A Fern P A A Pine P P A Daisy P P P

29 Moss Fern Pine Daisy Node 1 Common ancestor with vascular tissues Common plant ancestor (a) All of the plant groups shown here except mosses have vascular

30 Moss Fern Pine Daisy Node 2 Node 1 Common ancestor with vascular tissues Common plant ancestor (b) Seeds are a shared character for all plant groups shown here except mosses and ferns.

31 Moss Fern Pine Daisy Node 3 Node 2 Common seedproducing ancestor Node 1 Common ancestor with vascular tissues Common plant ancestor (c) Of the plant groups shown here, only the daisy produces flowers. Fig. 18-7c, p. 358

32 LEARNING OBJECTIVE 5 List and briefly describe the three domains and six kingdoms recognized by many biologists

33 KEY TERMS DOMAIN BACTERIA Domain of metabolically diverse, unicellular, prokaryotic organisms

34 KEY TERMS DOMAIN ARCHAEA Domain of unicellular, prokaryotic organisms adapted to extreme conditions (such as very hot or very salty environments)

35 KEY TERMS DOMAIN EUKARYA Includes all eukaryotic organisms (protists, plants, fungi, and animals)

36 The Three Domains

37 Domain Bacteria Domain Archaea Domain Eukarya Common ancestor of all living organisms Fig. 18-9, p. 360

38 Six-Kingdom Classification Kingdom Bacteria (domain Bacteria) Kingdom Archaea (domain Archaea) Kingdom Protista (domain Eukarya) Kingdom Fungi (domain Eukarya) Kingdom Plantae (domain Eukarya) Kingdom Animalia (domain Eukarya)

39 The Six Kingdoms

40 Bacteria Archaea Protista Plantae Protista Animalia Fungi Common ancestor of all eukaryotes Common ancestor of all living organisms

41 LEARNING OBJECTIVE 6 Summarize the scientific limitations of the kingdom Protista

42 KEY TERMS PARAPHYLETIC Said of a group consisting of a common ancestor and some, but not all, of its descendants

43 Kingdom Protista Ideally, all members of a kingdom should have a common ancestor Members of kingdom Protista are paraphyletic Some biologists think protists should not be grouped in a single kingdom

44 Animation: Constructing a Cladogram CLICK TO PLAY

45 Courtesy: Thomson Higher Questions are welcome?