This document provides an overview of biology and its branches from an introductory lecture. It defines biology and lists its main branches such as anatomy, ecology, molecular biology, and physiology. It also outlines characteristics of living things like homeostasis, adaptation, reproduction, growth and response to stimuli. Finally, it discusses the levels of cellular organization and provides a brief tour of the cell.

1. Dr. Abdul Matin, PhD, PDPhil, PGCHE
Associate Professor
Department of Medical Laboratory Sciences
Majmaah University, Kingdom of Saudia Arabia
Email: a.shafiqurhman@mu.edu.sa
Mobile: 0538569781
Biology (Bio-102)
Lecture-1
October 10, 2016

2. Campbell, N. A. and Reece, J. B.
2005
Biology
(6th edition)
Pearson Education. Inc. USA.

3. • Biology literally means "the study of life".
• Biology is such a broad field, covering the minute
workings of chemical machines inside our cells, to
broad scale concepts of ecosystems and global
climate change.
• Biologists study intimate details of the different
human organs, systems, composition of our
genes, and even the functioning of our
reproductive system.

4. • Biochemistry - the study of the chemical reactions
required for life to exist and function, usually a
focus on the cellular level
• Bioengineering - the study of biology through the
means of engineering with an emphasis on applied
knowledge and especially related to biotechnology.
• Bioinformatics - the use of information technology
for the study, collection, and storage of genomic
and other biological data

5. Branches of Biology
 These are the main branches of biology:
• Aerobiology - is a branch of biology that studies
organic particles, such as bacteria, fungal spores,
very small insects, pollen grains and viruses, which
are passively transported by the air (Spieksma,
1991).
• Anatomy - the study of form, in plants, animals, and
other organisms, or specifically in humans
• Astrobiology- the study of evolution, distribution, and
future of life in the universe. Also known as
exobiology, and bioastronomy.

6. • Biomathematics or Mathematical Biology - the
quantitative or mathematical study of biological
processes, with an emphasis on modeling.
• Biomechanics - often considered a branch of
medicine, the study of the mechanics of living
beings, with an emphasis on applied use through
artificial limbs, etc.
• Biomedical research - the study of the human body
in health and disease
• Biophysics - the study of biological processes
through physics, by applying the theories and
methods traditionally used in the physical sciences

7. • Biotechnology - a new and sometimes controversial
branch of biology that studies the manipulation of
living matter, including genetic modification.
• Botany - the study of plants
• Cell biology - the study of the cell as a complete
unit, and the molecular and chemical interactions
that occur within a living cell.
• Conservation Biology - the study of the
preservation, protection, or restoration of the natural
environment, natural ecosystems, vegetation, and
wildlife
• Cryobiology - the study of the effects of lower than
normally preferred temperatures on living beings.

8. •Developmental biology - the study of the processes
through which an organism forms, from zygote to full
structure.
•Ecology - the study of the interactions of living
organisms with one another and with the non-living
elements of their environment.
•Embryology - the study of the development of embryo
(from fecundation to birth). See also topobiology.
•Entomology - the study of insects
•Environmental Biology - the study of the natural
world, as a whole or in a particular area, especially as
affected by human activity

9. • Epidemiology - a major component of public health
research, it is the study of factors affecting the
health and illness of populations
• Ethology - the study of animal behavior.
• Evolutionary Biology - the study of the origin and
descent of species over time
• Genetics - the study of genes and heredity.
• Herpetology - the study of reptiles and amphibians
• Histology - the study of cells and tissues, a
microscopic branch of anatomy.

10. •Ichthyology - the study of fish
•Integrative biology - the study of whole organisms
•Limnology - the study of inland waters
•Mammalogy - the study of mammals
•Marine Biology - the study of ocean ecosystems,
plants, animals, and other living beings.
•Microbiology - the study of microscopic organisms
(microorganisms) and their interactions with other
living things

11. •Molecular Biology - the study of biology and biological
functions at the molecular level, some cross over with
biochemistry.
•Mycology - the study of fungi.
•Neurobiology - the study of the nervous system,
including anatomy, physiology, even pathology.
•Oceanography - the study of the ocean, including
ocean life, environment, geography, weather, and
other aspects.
•Oncology - the study of cancer processes, including
virus or mutation oncogenesis, angiogenesis and
tissues remolding

12. •Ornithology - the study of birds
•Population biology - study of the populations of
organisms - most often referred as ecology, or used to
point out biology adaptations, biology events sum up.
•Population ecology - the study of populations of
organisms, including how they increase and go extinct
(dynamics)
•Population genetics - the study of changes in gene
frequencies in populations of organisms
•Paleontology - the study of fossils and sometimes
geographic evidence of prehistoric life

13. • Pathobiology or pathology - the study of diseases,
and the causes, processes, nature, and
development of disease
• Parasitology - the study of parasites and
parasitism
• Pharmacology - the study and practical
application of preparation, use, and effects of
drugs and synthetic medicines.
• Physiology - the study of the functioning of living
organisms and the organs and parts of living
organisms
• Phytopathology - the study of plant diseases (also
called Plant Pathology)

14. • Psychobiology - study of the biological bases of
psychology
• Sociobiology - study of the biological bases of
sociology
• Structural biology - a branch of molecular biology,
biochemistry, and biophysics concerned with the
molecular structure of biological macromolecules
• Virology - the study of viruses and some other
virus-like agents
• Zoology - the study of animals, including
classification, physiology, development, and
behavior.

15. What is Life?
• Growth and development
• Metabolism
• Homeostasis
• Movement
• Response to stimuli
• Reproduction
• Evolution and adaptation

16. Characteristics of living things
•Living things have a variety of common
characteristics:
•Organization: Living things exhibit a high level of
organization, with multicellular organisms being
subdivided into cells, and cells into organelles, and
organelles into molecules, etc.
•Homeostasis: Homeostasis is the maintenance of a
constant (yet also dynamic) internal environment in
terms of temperature, pH, water concentrations, etc.
•Much of our own metabolic energy goes toward
keeping within our own homeostatic limits.

17. • If you run a high fever for long enough, the
increased temperature will damage certain
organs and impair your proper functioning.
• Swallowing of common household chemicals,
many of which are outside the pH (acid/base)
levels we can tolerate, will likewise negatively
impact the human body's homeostatic regime.
• Muscular activity generates heat as a waste
product. This heat is removed from our bodies by
sweating. Some of this heat is used by warm-
blooded animals, mammals and birds, to maintain
their internal temperatures.

18. • Adaptation: Living things are suited to their mode of
existence.
• Reproduction and heredity: Since all cells come from
existing cells, they must have some way of reproducing,
whether that involves asexual (no recombination of genetic
material) or sexual (recombination of genetic material).
• Most living things use the chemical DNA (deoxyribonucleic
acid) as the physical carrier of inheritance and the genetic
information.
• Some organisms, such as retroviruses (of which HIV is a
member), use RNA (ribonucleic acid) as the carrier.
• The variation that Darwin and Wallace recognized as the
wellspring of evolution and adaptation, is greatly increased
by sexual reproduction.

19. •Growth and development:
•Even single-celled organisms grow.
•When first formed by cell division, they are small, and must
grow and develop into mature cells.
•Multicellular organisms pass through a more complicated
process of differentiation and organogenesis (because they
have so many more cells to develop).
•Energy acquisition and release: One view of life is that it is a
struggle to acquire energy (from sunlight, inorganic chemicals,
or another organism), and release it in the process of forming
ATP (adenosine triphosphate).

20. • Detection and response to stimuli (both internal and external)
• Interactions: Living things interact with their environment as
well as each other.
• Organisms obtain raw materials and energy from the
environment or another organism.
• The various types of symbioses (organismal interactions with
each other) are examples of this.

21. Levels of organization

22. A tour of the cell
Cell Theory
1- All organisms are composed of one or more of cells.
2- Cell is the basic unit of life.
3- The new cell arises only from pre-existing cell.