BIOLOGY AND LIVING THINGS
CONTENT
Biology as Inquiry inScience
Process or Method of Science
Microscope Parts and Functions
BIOLOGY AS AN INQUIRY IN SCIENCE
Science is the study of nature (living and non-living things). Biology is a science that studies living
things in nature. Biology was formed from the Greek words "Bio" (meaning life) and “logos"
(meaning, study of).
The organisms studied in biology are generally classified into plants and animals. Therefore, biology
is a science subject that can be subdivided into two main branches or subjects namely:
a.
Botany –the study of plants.
b.
Zoology - the study of animals.
Other branches of biology include zoology, botany, microbiology, parasitology, anatomy, physiology,
biotechnology, etc.
RELEVANCE OF BIOLOGY
Biology has found great applications in many areas of human life, some of which include:
a.
Medicine: Production of drugs and vaccines for preventing and curing many diseases e.g.
penicillin, organ transplant e.g. kidney (renal) transplant, in-vitro fertilization in infertile couples.
b.
Agriculture: Production of hybrid (crops and animals with desired qualities), use of biological
pestic.ides to control agricultural pests
c.
Bioremediation i.e. use of naturally occurring bacteria to clean up oil spills and toxic
chemicals.
d.
Biotechnology: Use of genetic engineering to fight genetic diseases.
e.
Food production: Production of single cell protein (SCP) to reduce protein deficiency
problem, food storage and preservation
EVALUATION
1. What is biology.
2. Describe the following branches of Biology (a) parasitology (b) anatomy (c) physiology.
PROCESS OR METHOD OF SCIENCE
This is a systematic approach used to investigate enquiries arising from any observation made in
nature. Therefore, the scientific method is the tool used to unravel the mysteries of life. The
scientific methods include the following steps:
Observation
Classification
Inference
Measurement and Identification
Hypothesis
Experiment
Control or Conclusion
Theory or Law
The starting point of scientific method is observation which involves the use of the senses to
describe what one has seen or felt about an object. The observation then leads to classification,
then to inference (logical reasoning) and later to measurement and identification of the existing
problem. This is followed by hypothesis which is a reasonable explanation for an observation made
and which can be tested experimentally. A tested hypothesis may be accepted, rejected or modified
to form a new hypothesis. A tested hypothesis that is found to be repeatedly true within the limits of
available evidence becomes a theory. A theory is therefore an aggregate of many verified
hypotheses. An extensively tested and proven theory becomes a law or principle which is still
subject to change due to continual experimentation or research. To carry out a successful
experiment (void of false conclusions), a parallel experiment called controlled experiment is usually
set up. This is done by keeping constant all factors affecting the result of the main experiment and
varying the factor being tested.
Experiments should be reported following a generally accepted pattern laid down by scientists. The
pattern includes:
a.
Aim: the purpose of the experiment.
b.
Apparatus/ materials required.
c.
Method /procedure followed
d.
Observation made.
e.
Conclusion based on observation made and final result got.
Note: Precaution or care that should be taken against dangers/hazards can also feature during
experimentation.
EVALUATION
1. Define (a) Hypothesis
(b) Theory
2. List the steps in scientific methods.
(c) Principle
MICROSCOPE PARTS AND FUNCTIONS
A microscope is an instrument used in magnifying and viewing organisms smaller than 0.1mm that is
too tiny to be seen by the human eyes. A compound light microscope consists of the following parts:
a.
Revolving nose piece: it is used for selecting lens to be used and to be in line with the eye
piece.
b.
Objective lenses (low, medium and high power): for magnification of object
c.
Eye piece lens or ocular: for viewing magnified object.
d.
Body tube: provides attachment to eyepiece, revolving nose piece, low-power, medium-power
and high-power objective lens.
e.
Coarse focus knob: for focusing on object at low power.
f.
Fine adjustment knob: for focusing on object at medium and high power magnification so
that object is sharper at focus.
g.
Arm: for lifting or carrying the microscope.
h.
Clip: for holding glass slide on stage.
i.
Stage: for displaying slide and specimens under focus.
j.
Condenser: regulates the amount of light rays entering the microscope and object.
k.
Knob: to raise and lower the condenser.
l.
Base: for balancing the microscope on the table.
m.
Mirror: for collecting light rays and directing them to condenser and object.
EVALUATION
1. List five major parts of a microscope and their functions.
2. Mention two other types of microscopes.
GENERAL EVALUATION
1. “Biology is a science that studies life”. Explain.
2. State the various professions practicable with adequate knowledge of biology.
3. How relevant is biology to you as a living organism?
4. What is a scientific method?
5. Describe the pattern followed during experimentation in a scientific study.
READING ASSIGNMENT
Modern Biology, chapter 1, page 1 – 5.
WEEKEND ASSIGNMENT
1. Biology is a subject concerned with the study of ____ (a) living things (b) non-living things (c)
living and non-living things (d) climate.
2.
A parallel experiment done alongside a laboratory experiment is said to be _______
(a)
side experiment (b) certainty experiment (c) controlled experiment (d) emergency experiment.
3.
A reasonable explanation for any observation made in nature is scientifically termed ____ (a)
idea (b) theory (c) hypothesis (d) notion.
4.
_____ is a scientific fact (a) observation (b) theory (c) idea (d) hypothesis
5.
The part that regulates the amount of light entering a microscope is the (a) knob (b) fine
adjustment (c) condenser (d) objective lens
THEORY
1. State four relevance of biology to life.
2. List five careers in biology.