BIOLOGY Scientific study of life. Present era is most exciting in biology Scientists are trying to solve biological

puzzles like:How a single microscopic cell develops into

complex animals and plants?How plants converts solar energy to

chemical energy of food?How human mind works?How various forms of diverse life on earth

evolve from first microbe?

Evolution makes sense of everything we know about living organisms.

Organisms living on Earth are modified descendents of common ancestors Biology is a quest , on ongoing inquiry about the nature

of life. Modern biology is as important as it is inspiring Research breakthroughs in genetics and cell biology are

transforming medicine and agriculture. Molecular Biology is providing new tools to

anthropology and criminal science(Forensics). Neuroscience and evolutionary biology are reshaping

psychology and sociology New models in ecology are helping societies evaluate

environmental issues i-e. causes and biological consequence of global warming.

That’s how biology weaves into the fabric of our culture more than before.

This is a better time to explore life.

BIOLOGICAL HIERARCHY New properties emerge at each level in

the biological hierarchy Life can be studied at different levels

from molecules to the entire living planet The study of life can be divided into

different levels of biological organization

BIOLOGICAL HIERARCHY

BIOLOGICAL HIERARCHY

CELL Cell is fundamental unit to biology as atom is to

chemistry All organisms are made of cells. In the hierarchy of biological organization the cell

is the simplest collection of matter that can live. Single celled organisms are of diverse form Complex organisms: Plants and animals are multicellular; ● Have many kinds of specialized cells ● These cell can be survive on their own ● Tissues and organs can not survive on their

own either.

Cell is a basic unit of structure and function.

Various cells functions together or one after the other. i-e The contraction of muscle cells move your eyes as you read a sentence. When you decide to turn the next page, nerve cells transmit that decision from your brain to muscle cells of your hand.

Every thing an organism does occurs fundamentally at cellular level.

Life at cellular level arises from structural order, reinforcing the themes of emergent properties and correlation between structure and function. i-e The movement of an animal cell depends on an intricate interplay of the structure that make up a cellular skeleton.

SKELETON OF THE CELL

Interaction of organisms with their environment. Cells sense and respond to environmental fluctuations.

All cells are related by their descent from earlier cells. However they have been modified in many different ways during long evolutionary history of life on earth.

Although the cells differ substantially from each other they share certain common characteristics.

A eukaryotic cell has membrane-enclosed organelles, the largest of which is usually

the nucleus By comparison, a prokaryotic cell is

simpler and usually smaller, and does not

contain a nucleus or other membrane-enclosed organelles Bacteria and Archaea are prokaryotic;

plants, animals, fungi, and all other forms of life are eukaryotic

BACTERIAL CELL

PLANT AND ANIMAL CELLS

INHERITANCE OF LIFE Theme: The continuity of life is based on

heritable information in the form of DNA Chromosomes contain most of a cell’s

genetic material in the form of DNA (deoxyribonucleic acid)

DNA is the substance of genes Genes are the units of inheritance that

transmit information from parents to offspring

INHERITANCE

STRUCTURE AND FUNCTION OF DNA

Each chromosome has one long DNA molecule

with hundreds or thousands of genes DNA is inherited by offspring from their

parents DNA controls the development and

maintenance of organisms Each DNA molecule is made up of two long chains arranged in a double helix Each link of a chain is one of four kinds of chemical building blocks called

nucleotides

DEOXYRIBONUCLEIC ACID (DNA)

CHROMOSOME

GENOME Genes control protein production indirectly DNA is transcribed into RNA then

translated into a protein An organism’s genome is its entire set of

genetic instructions The human genome and those of many

other organisms have been sequenced using DNA sequencing machines.

Knowledge of a cell’s genes and proteins can

be integrated using a systems approach

HUMAN GENOME (CHROMOSOMES)

HIGH THROUGHPUT GENOMICS

BIOINFORMATICS Advances in systems biology at the

cellular and molecular level depend on “High-

throughput” technology, which yields enormous amounts of data -

Bioinformatics, which is the use of computational tools to process a large volume of data

Interdisciplinary research teams

ANIMAL CELL

PLANT CELL

PLANT AND ANIMAL CELL

PLANT AND ANIMAL CELL

PLANT CELL

BACTERIAL CELL

Cell structure and Function

NERVE CELL

CELL DIVISION (MITOSIS)

CELL STRUCTURE AND FUNCTION

ANIMAL MUSCLE CELL

ANIMAL MUSCLE FIBER

RED BLOOD CELLS