Saturday, November 8, 2008

What is Botany?

Botany or Plant Biology, is the scientific study of plants. In fact, Botany is the branch of biology that deals with plants. Botanists (like me), are scientist who study plants.

Botany comes from 3 Greek words;
botanikos = botanical
botane = plant or herb
3). boskein = to feed

Botany's scope is extensive. Its time frame extends from the present back to almost 3.5 billion years ago, the age of the earliest fossilized cells. At first, the interest in plants was mostly practical and centered around how plants might provide food, fibers, fuel and medicine. Eventually, however, an intellectual interest arose. Individuals became curious about how plants functioned and how they reproduced. This inquisitiveness led to plant study becoming a science (Botany and Plant Biology).

Botany comprises many disciplines because of its immerse scope;

i) Plant molecular biology
-Study the structures and functions of important biological molecules such as proteins and nucleic acids.

ii) Plant Biochemistry
-The study of the chemical interactions within plants, in
cluding the variety of chemicals that plants produce.

iii) Plant Anatomy
=>Concerned chiefly with the internal structure of plants.
-Early plant anatomist of note included:

i. Marcello Malpighi (1628-
1694) from Italy. He discovered various tissue in stems
and roots.

ii. Nehemiah Grew (1628-1711) from England, described the structure of wood more precisely than any of his predecessors.

Marcello Malpighi (left) and Nehemiah Grew(right)
- Today, a knowledge of plant anatomy is used to help us find clues to the past, as well as for many practical purposes.
- For example, the related discipline of 'dendrochronology' deals with determining past climates by examining the width and other features of tree rings.
- We can also learn much from archeological sites by matching tree rings found in the wood of ancient buildings to the rings of wood of known age.

- Plant anatomy is also used to solve crimes.
- Forensic Laboratories may use fragment of plant tissue found on clothing or under fingernails to determine where a crime took place or if certain p
erson could have been present where the crime was committed.
- The anatomy of leaves, stems and other plant parts are currently being used to unravel and sort out relationship among plants.
- A form of plant anatomy called 'paleobotany' involves the study of plant fossils.

iv) Plant Physiology

Concerned with plant functions.

Established by
Johann Baptist Van Helmont (1577-1644), a Flemish physician and chemist.
- He was the first to demonstrate that plants do not have the same nutritional needs as animals.

- He planted a willow branch weighing 5 pounds in an earthenware tub filled with 74.4kg (200 pounds) of dry soil.
- He covered the soil to prevent dust settling on it from air.
- The willow produced roots and grew, and after 5 years, he reweighed the willow and soil.
- He found that the soil weighed only 56.7 grams (2 ounces) less than it had at the beginning of the experiment, but the willow had gained 164 pounds.
- He concluded that the tree had added to its bulk
and size from the water it had absorbed.
- Of course, at glance we know that most of the weight came as a result of photosynthetic activity, but this Van Helmont deserves credit for landmark experimentation in plant physiology.
Johann Baptist Van Helmont

- Modern plant physiologists use cloned 'genes' (units of heredity that are found within the nuclei of cells) to learn in precise details much mor
e about plant functions, including;

i. How plants conduct materials internally?
ii. How temperature, light and water are involved in growth?
iii. Why plants flower?

iv. How plant growth regulatory substances are produced

and many more... just to mention a few.

- During past centuries, Europeans who explored other continents took large numbers of plants back home with them.
- Soon, it became clear to those working with the plants that some sort of formalized system was necessary just to keep the collections straight.
- Several 'plant taxonomist' (botanist who specialize in the identifying, naming and classifying plants) proposed ways of accomplishing this.

- But, we owe much of our present system of naming and classifying plants to the Swedish botanist named Carolus Linnaeus (1707- 1778).

Carolus Linnaeus

v) Plant Taxonomy

Involves describing, naming and classifying organisms.

Plant Systematics is a related field, but is broader than taxonomy. This one is the science of developing methods for grouping organisms.

- Plant taxonomy is the oldest branch of plant study, began in antiquity.
- However, Linnaeus did more for the field than any other person in history.
- Thousands of plant names in use today are th
ose originally recorded in Linnaeus's book Species Plantarum, published in 1753.
Species Plantarum

- There are still thousands of plants, fungi and other organisms that have not yet been described or even discovered.
- Although it obviously is already too late to identify species that were not described before they became extinct, plant taxonomist around the world have united to try to identify and describe as many new organisms - many with food, medicinal and other useful potential- before much more of their natural habitat disappears.
- Other plant taxonomists, through the use of 'cladistics' (analysis of shared features) and molecular techniques, are refining our knowledge of plant relationship.
- The molecular knowledge and techniques are also contributing to the improvement of many of our food crops, although some of the changes are controversial (like GMO, I'll discuss this in details later)
- Plant taxonomist often specialize in certain groups of plants.
'Pteridologist' - Specialize in the study of ferns
'Bryologist' - Study mosses and plants with similar life cycle.

vi) Plant Geography
The study of how and why plants are distributed in where they are.
- Did not develop until the 19th century.

- This field is the allied field of Plant Ecology, the study of the interaction of plants with one another and with their environment (also develop in the 19th century)
- Ecologist, plant geographers and other biologists recognize large communities of plants and animals that occur in areas with distinctive combination of environmental features.
- Such areas are called 'biomes'.
- For instance, Tropical Rain Forest.
- Although occupying less than 5% of the earth's surface, it is home to more than half of the world's species of organisms!

Tropical Rain Forest

vii) Plant Morphology
==> The study of the form and structure of plants.

- It was developed during the 19th century.
- During the 20th century, much of our basic knowledge about the form and life cycles of
plants was incorporated in the plant sciences as we know them today.
- During this time, the number of scientist who engaged in investigating plants also greatly

vii) Genetics
==> The science of heredity.

- Founded by an Austrian monk,Gregor Mendel (1822-1884) who performed classic
experiments with pea plants (Pisum sativum).
- Today, various branches of genetics include Plant Breeding (i love this) and Genetic Engineering.
- Plant breeding has greatly improved yields and quality of crop plants.
- For genetic engineering, it includes the introduction of genes from one organism to another
and has already improved the pest, frost and diseases resistance, as well as yield for some
crops. I will discuss this in details later as it's a very controversial topic.

Gregor Johann Mendel

viii) Cell Biology (previously called cytology)
==> The science of cell structure

- This field of study has received a boost from the discovery of how cells multiply and how
their various components perform and integrate a variety of functions, including that of sexual reproduction.
- The invention of electron microscopes has further spurred cell research and led to vast new
insights into cells and new forms of cell research.

ix) Ethnobotany and Economic Botany
==> Involve practical uses of plants and plant products.

- Both had their origin in antiquity as humans discovered, used, and eventually cultivated plants for food, fiber, medicines, and other purposes.

1 comment:

daniel john said...

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