Chapter #1 Introduction to Botany

Botany, plant science(s), phytology, or plant biology is a branch of biology that involves the scientific study of plant life. Botany covers a wide range of scientific disciplines concerned with the study of plants, algae and fungi, including structure, growth, reproduction, metabolism, development, diseases, chemical properties, and evolutionary relationships between taxonomic groups.

The main subject matter in this course is:

A) Life : the characteristics of living things
B) Biochemistry : the important biological chemicals, like proteins and sugars
C) Cell structure : what plant cells contain
D) Chemical reactions : respiration and photosynthesis
E) Cell division : including meiosis
F) Plant ancestors and relatives : bacteria, protists and fungi
G) The plant kingdom : spore plants, seed plants
H) The applications of botany: crops, plant breeding and ecology

Why study Botany?
Plants are the source of many important products such as:
Food (including grass for animals)
Cotton and other fabrics
Paper
Wood
Coal and oil
Antibiotics and other medicines

Botany as a Science
Sciences, such as Biology, Chemistry and Physics, use a series of steps, called the scientific method, to try to understand the world around us. Some of the main steps are:

1-Make an observation (for example: plants in one part of my yard grow faster).
2-Come up with a hypothesis : an idea that can be tested. (eg. part of the yard gets more sunlight)
3-Make a prediction : a logical consequence of a hypothesis. (if slow growing plants are given more sunlight they will grow faster)
4-Test the prediction by conducting an experiment. Experiments are often designed to disprove the hypothesis. It is easy to disprove a hypothesis, but virtually impossible to prove that a hypothesis is correct in all possible situations.

The experimental group differs from the control group usually in one variable eg amount of sunlight. Experiments should be repeatable. Sample size : the larger the sample, the more accurate the results. It is better to do an experiment with 200 plants than with 2 plants.

Theory : a scientific theory has been supported by many experiments eg atomic theory, the theory of evolution.

The main areas of Botany

Plant anatomy: the structure of plants
Plant physiology: the function of parts of the plant
Plant taxonomy: the classification of plants
Plant ecology: the interactions of plants and other species
Genetics: the study of inheritance
Economic botany: the practical uses of plants and plant products.

Biological Classification
Organisms are classified (put into groups) using this system devised by the Swedish biologist Linnaeus, around 1750.

The example below is the classification of corn:

Kingdom Plantae
Phylum ( Phyla ) Magnoliophyta
Class Monocots (Liliopsida)
Order Commelinales
Family Poaceae (grasses)
Genus ( Genera ) Zea
Species mays
The scientific name is the Genus name followed by the species name eg Zea mays.
Members of the same species can interbreed to produce fertile offspring. Members of the same genus are similar, but do not interbreed in the wild. Example: wild perennial maize (Zea perennis ) is in the same genus as corn, but they do not interbreed.