B50. 001- Access Biology
Course Developers Dr. S. J. Oniye ABU, Zaria Mr. Peter Tunku ABU, Zaria
Unit Writers Dr. S. J. Oniye ABU, Zaria Mr. Peter Tunku ABU, Zaria
Course Co-ordinator M. K. Olubiyi NOUN, Lagos
Edited by Prof. C. O. Akueshi University opos
National Open University of Nigeria
■ National Open University of Nigeria
Headquarters 14/16 Ahmadu Bello Way Victoria Island Lagos
Abuja Anner Office 245 Samuel Adesujo Ademulegun Street, Central Business District OppositeArewa Suites Abuja e-mail: [email protected] url: wwwnou.edu.ng
C) National Open University of Nigeria 2004 First published 2004
ISBN 978 058 384 X
All Rights Reserved
Published by Folubee Prints for National Open University of Nigeria Programme: B.Sc Science and Technology
Course: Access Biology
Duration: First Semester
Programme Leader: Dr. M. A. Wasagu
iii Contents
Volume 1 Basic Concepts in Biology 1
Unit 1 Biology as a Science 1 Unit 2 , Classification of Living Organisms II Unit 3 Viruses 18 Unit 4 Bacteria 25 Unit 5 Protozoa 35 Unit 6 • Paramecium, Biological and Economic Importances-of Protozoa 43 Unit 7 Fungi 53 Unit 8 Algae 63 Unit 9 Mosses 70 Unit 10 Ferns 77
Volume 2 Flowering Plants 83
Unit 1 Characteristics of Flowering Plants - Differences between Gymnosperms and Angiosperms 83 Unit 2 Differences between Monocotyledons and Dicotyledons — Morphology of Angiosperms — Root System 89 Unit 3 Shoot System - Stems, leaves, flower and fruits 101 Unit 4 Important Definitions - Herbs, Shrubs, Trees, Ephemeral, Annual, Biennial, Perenial Plants 124 Unit-5 Nutrition in Plants 129 Unit 6 Co-ordination and Control in Plants 138 Unit 7 Transport and Transpiration in Plants 144 Unit 8 Respiration in Plants 155 Unit 9 Reproduction in Plants 165 Unit 10 Growth and Development in Plants 185
Volume 3 Regulatory Systems and Mechanisms in Animals 201
Unit 1 Regulatory Processes 201 Unit 2 The Mammalian liver 206 Unit 3 The Mammalian kidney '12 Unit 4 The Mammalian skin 218 Unit 5 Hormones in Animals 222 Unit 6 Nervous Coordination and Sense Organs in Animals 228 Unit 7 Locomotion in Animals 243 Unit 8 Respiration (Gaseous Exchange) in Animals 256 Unit 9 Nutrition and Transport System inAnimals 264 Unit 10 Reproduction in Animals 285 iv Volume 4 Evolution and Genetics 303
Unit 1 Evolutionary Theories, Evidence of Evolution and Modern view on Evolution 303 Unit 2 Modem Examples of Evolution (Microevolution); classification and evolution 316 Unit 3 Common Terms in Genetics Transmission and Expression of Characters — Hereditary Variation 322 Unit 4 Mendels work in Genetics — Chromosomes as a Basic of Inheritance Heredity and Environment — Probability in Genetics 331 Unit 5 Application of Genetics 347
Volume 5 Ecology 155
Unit 1 Basic Concepts and Principles in Ecology 55 Unit 2 Feeding Relationships in Ecology 1160 Unit 3 Interactions in an Ecosystem 166 Unit 4 Adaptation by Animals to different Environments 37C Unit 5 Adaptations by Plants to Different Environments 1 7-1 Unit 6 Habitat Studies 1 79 Unit 7 Population Studies Unit 8 Nutrient Cycles 392 Unit 9 Pollution and En% ronmental Health problems 399 Unit 10 Conservation of Natural resources 405 . Volume 1: Basic Concepts ineBiology
Page
1.0 Introduction 2 2.0 Objectives 2 3.0 Definition of Biology 2 3.1 Characteristics of Living Things 2 3.2 Differences between Plants and Animals 2 3.3 Microscope 3 3.4 Plant and Animal Cell 3.4.1 Plant Cell 4 3.4.2 Animal Cell 3.5 Differences between Plant and Animal Cells 6 3.6 Similarities between Plant and Animal Cells 6 3.7 Cell Division 6 3.7.1 Meiosis 6 3.7.2 Mitosis 8 3.8 The Cell and Exchange of Materials 9 3.8.1. Diffusion 9 3.8.2. Osmosis 9 3.8.3. Plasmolysis 10 4.0 Conclusion 10 5.0 Summary 10 6.0 Tutor MarkedAssignment 10 7.0. Further Reading and Other Resources 10
1 2 Access Biology
Biology is a science that deals with the living world. Its methods of i 1)::tiry are similar to those employed in all natural sciences. It is a fascinating study that ranges from microscopic cellular molecules to the multicellular macro forms of life, encompassing the earth's surface and its living organisms. The unit examines the characteristics of living things which distinguish them from non-living things, plant and animal cells, cell division and the exchange of materials within a cell.
By the end of this unit, you should be able to: (a) define what Biology is; (b) distiguish between living things and non-living things; (c) show diagrammatically plant and animal cell; (d) describe the two types of cell division; (e) describe the process involved in the exchange of materials within a cell.
Biology is the branch of science that involve the study of living things (Plant and animals)
3.1 Characteristics of Living Things Living things can be distinguished from non-living things by a number of characteristics. (a) Movement:- All living things move. Movement means a change in position which could be total one location to another) as in the case of animals or limited to one part of the body as in plant,. (b) Nutrition:- A Living organism needs food to supply the energy and materials for life pt c, sses. Nutrition involves the total process of taking in, and the utilisation of foods in animals; as well as taking in of mineral substances and their utilisation in plants. (c) Respiration:- This is the break down of food substances taken in by the organism to release energy. (d) Irritability (Sensitivity):- This is the ability of a living organism to receive an external stimulus and respond to it. (e) Excretion:- This is the removal of waste products of metabolism from'the body of a living organism. (f) Reproduction:- This is the process of giving rise to new individuals of the same kind for the continuation of life. Reproduction may be sexual or asexual in nature. (g) Growth:- A living organism grows. This is an increase in size which is usually accompanied by development (a change in form and abilities). The materials used for growtlur derived from the food taken in by the organism. (i) Adaptation:- This is the posession of features (structures or functions) which enable organisms to live successfully and to survive in their respective environments.
3.2 Differences between Plants and Animals There are notable differences between plants and animals. These are shown in Table 1.1 Biology as a Science 3
Table .1.1
FEATURES PLANT ANIMALS 1. Nutrition Autotrophic nutrition, Heretotrophic Nutrition, obtain i.e. makes own food by complex organic food already Photosynthesis, since it made. is green and has clorophyll. 2. Support Depends on tugor and Many Possess an lignifield tissues. endoskeleton or an exoskeleton. 3. Movement Rooted on one spot. The whole animal can Movement is generally move about quickly. slow since usually is as a result of growth. 4. Sensitivity Responds slowly to Sensory system allows stimulus by means of rapid responses. hormones. 5. Growth May grow large with Body is compact, growth branching body. Growth stops at maturity in higher which is mostly at animals. meristems, is indefinite. 6. Cell Structure Cellulose cell wall and Cell wall is absent. vacuoles containing cell Vacuole and chloroplast, sap are present, may are absent. contain Chloroplasts.
Source: Federal Government School Practical Book
3.3 Microscope Microscopes are instruments which magnify the size of objects. There are various types. Simple, Compound and Electron microscope. The diagram below (Fig. 1) shows a simple type.
Eyepiece lens
coarse adjusment Objective Knob Lenses
S a cover slip mounting Iris needle
Mirror Slide Fine Adjustment Kno specimen mounted in a drop of water bas