Dr. Abdul Matin, PhD, PDPhil, PGCHE

Associate Professor

Department of Medical Laboratory SciencesMajmaah University, Kingdom of Saudia Arabia

Email: a.shafiqurhman@mu.edu.sa Mobile: 0538569781

Biology (Bio-102)Lecture-1

October 10, 2016

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

• 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.

• 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

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.

• 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

• 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.

•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

• 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.

•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

•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

•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

• 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)

• 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.

What is Life?

• Growth and development• Metabolism• Homeostasis• Movement• Response to stimuli• Reproduction• Evolution and adaptation

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.

• 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.

• 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.

•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).

• 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.

Levels of organization

A tour of the cell

Cell Theory1- 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.