GENERAL ZOOLOGYLectured by Bien Nillos, MD

Zoology

the branch of biology which relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct.

Zoon + logos = “animal” + “knowledge”

Areas in the Study of Zoology

• Structural – cell biology, anatomy– Understanding the structure and function of

cells is fundamental to all of the biological sciences.

– Anatomy considers the forms of macroscopic structures such as organs and organ systems

Coronal

Transverse

Median

Sagittal

• Physiological - studies the mechanical, physical, and biochemical processes of living organisms by attempting to understand how all of the structures function as a whole

DNA = deoxyribonucleic acid

PROTEIN synthesis

• Transcription

• Initiation

• Elongation (Translation)

• Termination

Meiosis• Before meiosis, the cell's chromosomes are duplicated by a round of DNA

replication, (homologs = composed of two exact copies called sister chromatids)

• In the beginning of meiosis, the maternal and paternal homologs pair to each other. Then they typically exchange parts by homologous recombination, leading to crossovers of DNA from the maternal version of the chromosome to the paternal version and vice versa.

• Spindle fibers bind to the centromeres of each pair of homologs and arrange the pairs at the spindle equator.

• Then the fibers pull the recombined homologs to opposite poles of the cell. • As the chromosomes move away from the center, the cell divides into two

daughter cells, each containing a haploid number of chromosomes composed of two chromatids.

• After the recombined maternal and paternal homologs have separated into the two daughter cells, a second round of cell division occurs.

• There meiosis ends as the two sister chromatids making up each homolog are separated and move into one of the four resulting gamete cells.

Mitosis

• The sequence of events is divided into stages corresponding to the completion of one set of activities and the start of the next.

• These stages are interphase, prophase, prometaphase, metaphase, anaphase and telophase.

• During mitosis the pairs of chromatids condense and attach to fibers that pull the sister chromatids to opposite sides of the cell.

• The cell then divides in cytokinesis, to produce two identical daughter cells.

• Evolutionary Research - concerned with the origin and descent of species, as well as their change over time, and includes scientists from many taxonomically oriented disciplines. For example, it generally involves scientists who have special training in particular organisms such as mammalogy, ornithology, or herpetology, but use those organisms as systems to answer general questions about evolution.

After swabbing the cheeks of more than 200 lemurs and related primates to

collect their DNA, researchers at the Duke

Institute for Genome Sciences & Policy (IGSP) and Duke Lemur Center now have a much clearer

picture of their evolutionary family tree.

http://www.physorg.com/news123176037.html

• Systematics - a method by which zoologists group and categorize organisms by biological type, such as genus or species. Biological classification is a form of scientific taxonomy.– Carolus Linnaeus - grouped species according to

shared physical characteristics. These groupings have since been revised to improve consistency with the Darwinian principle of common descent.

– Molecular phylogenetics, which uses DNA sequences as data, has driven many recent revisions and is likely to continue to do so. Biological classification belongs to the science of zoological systematics.

• Kids Prefer Cheese Over Fried Green Spinach.

• King Philip Came Over From Great Spain

• Many scientists now consider the five-kingdom system outdated.

• Modern alternative classification systems generally begin with the three-domain system: Archaea (originally Archaebacteria); Bacteria (originally Eubacteria); Eukaryota (including protists, fungi, plants, and animals) These domains reflect whether the cells have nuclei or not, as well as differences in the chemical composition of the cell exteriors

• The dominant classification system is called the Linnaean taxonomy. It includes ranks and binomial nomenclature. The classification, taxonomy, and nomenclature of zoological organisms is administered by the International Code of Zoological Nomenclature, and International Code of Nomenclature of Bacteria for animals and bacteria, respectively. The classification of viruses, viroids, prions, and all other sub-viral agents that demonstrate biological characteristics is conducted by the International Code of Virus classification and nomenclature

• Ethology - studies animal behavior and is sometimes considered a separate branch of study. Ethologists have been particularly concerned with the evolution of behavior and the understanding of behavior in terms of the theory of natural selection. In one sense, the first modern ethologist was Charles Darwin, whose book, The Expression of the Emotions in Man and Animals, influenced many ethologists to come

LIFE

• 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.

• 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).

• 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

• 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). – property of irritability/excitability

• 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

Questions?

“Every person is the creation of himself, the image of his own thinking and believing. As individuals think and believe, so they are.” - Claude M. Bristol

• http://www.emc.maricopa.edu• http://en.wikipedia.org/wiki/Zoology