Form 1:
Classification 1

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Introduction

Classification refers to the grouping of living organisms according to their structure.

Classification is based on the study of external characteristics of organisms.

It involves detailed observation of structure and functions of organisms.

Organisms with similar characteristics are put in one group.

Differences in structure are used to distinguish one group from another.

In classification, organisms that share a lot of similarities are placed under one group referred to as a taxon (plural= taxa).

Other than the similarities, grouping of the organisms also takes into account the evolutionary relationships (phylogeny) of the organisms.

It is believed that all organisms once had a common ancestor (theory of evolution).

During classification, organisms that are believed to have evolved along the same line of evolution are placed in one taxon.

The scientific study of classification is known as taxonomy. A biologist studying taxonomy is a taxonomist.

In classifying organisms taxonomists to a great extent rely on the use of external observable features of organisms.

Using a Magnifying Lens

Image:Magnifying lens

How to use a magnifying lens:

• Place the object to be enlarged on the bench.

•Hold the magnifying lens on one hand and while closing one eye, move the lens towards the object until the image comes into clear focus.

Magnification has no units

The magnification of the drawing can be calculated using the formula shown below.
Drawing magnification=length of the drawing/length of the actual object.

The sign of times must come before the magnification value e.g. X10, X5, X15 etc.