(Study Material) Botany Study Material For AIPMT and State PMT Examination (Concepts in Botany)
Study Material : Botany Study Material For AIPMT and State PMT Examination (Concepts in Botany)
Introduction
Botany is the scientific study of plant life. As a branch of biology, it is also
called plant science(s), phytology, or plant biology. Botany covers a wide range
of scientific disciplines that study plants, algae, and fungi including:
structure, growth, reproduction, metabolism, development, diseases, and chemical
properties and evolutionary relationships between the different groups.
The study of plants and botany began with tribal lore, used to identify edible,
medicinal and poisonous plants, making botany one of the oldest sciences. From
this ancient interest in plants, the scope of botany has increased to include
the study of over 550,000 kinds or species of living organisms.
Scope and importance of botany
As with other life forms in biology, plant life can be studied from different
perspectives, from the molecular, genetic and biochemical level through
organelles, cells, tissues, organs, individuals, plant populations, and
communities of plants. At each of these levels a botanist might be concerned
with the classification (taxonomy), structure (anatomy and morphology), or
function (physiology) of plant life.
Historically, botany covers all organisms that were not considered to be
animals. Some of these "plant-like" organisms include fungi (studied
in mycology), bacteria and viruses (studied in microbiology), and algae (studied
in phycology). Most algae, fungi, and microbes are no longer considered to be in
the plant kingdom. However, attention is still given to them by botanists, and
bacteria, fungi, and algae are usually covered in introductory botany courses.
The study of plants has importance for a number of reasons. Plants are a
fundamental part of life on Earth. They generate the oxygen, food, fibres, fuel
and medicine that allow higher life forms to exist. Plants also absorb carbon
dioxide through photosynthesis, a minor greenhouse gas that in large amounts can
affect global climate. It is believed that the evolution of plants has changed
the global atmosphere of the earth early in the earth's history and
paleobotanists study ancient plants in the fossil record. A good understanding
of plants is crucial to the future of human societies as it allows us to:
* Produce food to feed an expanding population
* Understand fundamental life processes
* Produce medicine and materials to treat diseases and other ailments
* Understand environmental changes more clearly
Human nutrition
All foods eaten come from plants, either directly from staple foods and other
fruit and vegetables, or indirectly through livestock or other animals, which
rely on plants for their nutrition. Plants are the fundamental base of nearly
all food chains because they use the energy from the sun and nutrients from the
soil and atmosphere and convert them into a form that can be consumed and
utilized by animals; this is what ecologists call the first trophic level.
Botanists also study how plants produce food we can eat and how to increase
yields and therefore their work is important in mankind's ability to feed the
world and provide food security for future generations, for example through
plant breeding.
Botanists also study weeds, plants which are considered to be a nuisance in a
particular location. Weeds are a considerable problem in agriculture, and botany
provides some of the basic science used to understand how to minimize 'weed'
impact in agriculture and native ecosystems. Ethnobotany is the study of the
relationships between plants and people.
Fundamental life processes
Plants are convenient organisms in which fundamental life processes (like cell
division and protein synthesis for example) can be studied, without the ethical
dilemmas of studying animals or humans. The genetic laws of inheritance were
discovered in this way by Gregor Mendel, who was studying the way pea shape is
inherited.
What Mendel learned from studying plants has had far reaching benefits outside
of botany. Additionally, Barbara McClintock discovered 'jumping genes' by
studying maize. These are a few examples that demonstrate how botanical research
has an ongoing relevance to the understanding of fundamental biological
processes.
Medicine and materials
Many medicinal and recreational drugs, like tetrahydrocannabinol, caffeine, and
nicotine come directly from the plant kingdom. Others are simple derivatives of
botanical natural products; for example aspirin is based on the pain killer
salicylic acid which originally came from the bark of willow trees.[2] There may
be many novel cures for diseases provided by plants, waiting to be discovered.
Popular stimulants like coffee, chocolate, tobacco, and tea also come from
plants. Most alcoholic beverages come from fermenting plants such as barley malt
and grapes.
Plants also provide us with many natural materials, such as cotton, wood, paper,
linen, vegetable oils, some types of rope, and rubber. The production of silk
would not be possible without the cultivation of the mulberry plant. Sugarcane,
rapeseed, soy and other plants with a highly-fermentable sugar or oil content
have recently been put to use as sources of biofuels, which are important
alternatives to fossil fuels, see biodiesel.
Environmental changes
Plants can also help us understand changes in on our environment in many ways.
• Understanding habitat destruction and species extinction is dependent on an
accurate and complete catalog of plant systematics and taxonomy.
• Plant responses to ultraviolet radiation can help us monitor problems like
the ozone depletion.
• Analyzing pollen deposited by plants thousands or millions of years ago can
help scientists to reconstruct past climates and predict future ones, an
essential part of climate change research.
• Recording and analyzing the timing of plant life cycles are important parts
of phenology used in climate-change research.
• Lichens, which are sensitive to atmospheric conditions, have been
extensively used as pollution indicators.
In many different ways, plants can act a little like the 'miners canary', an
early warning system alerting us to important changes in our environment. In
addition to these practical and scientific reasons, plants are extremely
valuable as recreation for millions of people who enjoy gardening, horticultural
and culinary uses of plants every day.
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