Does Love Drive You Mad?

In 1990, a study in Italy indicated that people who have recently fallen in love have some of the symptoms of 'Obsessive Compulsive Disorder' or OCD. People with OCD behave obsessively about certain things. They might be constantly washing their hands, or need to continually check to see if the door is closed.

Does love make you sad?
Rather than making you happy, love could actually make you depressed. One symptom of OCD appears to be unusually low levels of the neuro-transmitter 'serotonin'. Low levels of serotonin have been associated with anxiety and depression. Italian students who claimed they had recently fallen in love were found to have serotonin levels 40% lower than their peers.

However, the biochemical effect of falling in love didn't last forever. When the same students were tested after their relationship was a year old, their levels had returned to normal. One author of the study has suggested that we require this chemical response for relationships to survive. After all, we'd have to be mad to fall in love wouldn't we?

Virility
Another interesting finding is that people with low serotonin levels tend to have a lot of sex. If men have a particular version of a gene known as the 'serotonin transporter', they will have lower levels of serotonin in their brains. They tend to be more anxious than other men and also more sexually active.

Love on the brain
Brain imaging techniques have been put to use in the name of love. Andreas Bartels and Semir Zeki at University College London used functional Magnetic Resonance Imaging (fMRI) to take pictures of the lover's brain.

Whilst inside the scanner, loved-up students were shown pictures of their new flame. They were also shown images of platonic friends of the opposite sex. Zeki and Bartels were struck by how clear cut the pattern of brain activity was when students were looking at their new love.

Four areas of the brain became active, and one area noticeably inactive, when the students had love on their mind. The active areas include one responsible for 'gut' feelings and one that is known to respond to euphoria-inducing drugs. The lights go off however, in the prefrontal cortex, an area that is overactive in depressed patients.

Source: BBC

Sea Lions

Rob Morrison: Sea lions are the undersea acrobats of the animal kingdom. With the smallest flick of their tails and flippers they can twist and turn effortlessly to catch fish or simply play. And they do a lot of playing. But on land, it's a different story. There, they are ungainly and cumbersome. Most of the time they sleep and a walk among them shows just how easy it was for seal hunters 200 years ago to club them as they lay - killing them by the thousand for their skins.

Unlike true seals, sea lions have small ears visible on their heads. There are five species of sea lions worldwide and the Australian sea lion, which is only found in southern Australia is one of the rarest, as a threatened species that needs protection. But for that to be effective, much more needs to be known about how these animals live, where they travel and what they eat. Dr Simon Goldsworthy is a leading expert on Australian sea lions and he's using space-age technology to reveal the hidden secrets of these elusive animals.

Dr Simon Goldsworthy: Like many seal species around the world the Australian sea lions were subject to fairly unregulated, uncontrolled sealing in the early to late 1800s. Many of those populations have still not recovered. And the range of the species also contracted. They are listed as a threatened species and so we need to understand more about where they go to sea to feed. We use satellite transmitters which are small microprocessors we glue to the backs of seals. And they produce a signal when the animal surfaces and that signal's transmitted up to an orbiting satellite and we can get information on the locations of these animals when they're at sea.

All other seal species in the world breed every 12 months, roughly. The Australian sea lion's breeding seasons occur about every year and a half. It's very easy to access their breeding colonies. Some colonies we've been tracking are at the base of the Bunda Cliffs on the Great Australian Bight. That's very challenging. They're 70-metre cliffs so it's a very long drop on a rope. We used the State Emergency Service to make sure that we could get our crew down to the bottom of the cliffs, into the colony safely.

Sea lions are very shy animals and they don't like being disturbed. They can get rather anxious. So we have to keep very low to the ground and sneak up on it and place a hoop net over its head. The Australian sea lion is quite a large animal and they're very, very powerful and muscular so it's important that we restrain them physically very quickly, so that requires two or three people to sit on top of the animal and hold it in as many places as it can. And then there's a delicate moment where we've gotta set up our gas anaesthetic machine so we can place a mask around the mouth. And that's quite a dangerous activity, as you can imagine, because these seals have got very large, sharp teeth. Once that's happened we only need the animal to take two or three breaths and it goes to sleep.

We're actually gluing the transmitter to the hair of the animal - not to the skin. The transmitter can remain on for many months and not harm the animal. And when we go to recover the instrument - this could be anywhere between several weeks or several months after we've actually attached the transmitter - we can then just carefully cut away the glue against the hair of the animal. Instruments we don't recover, the animals simply moult the transmitter off - it's usually just after breeding season.

All our transmitted data goes to France initially and gets processed there and we can then access it directly online from our office, on the computer. Here's a track for one individual. What we can do is connect the location points with lines and you get a trace - or a foraging route - of the animal while it's been at sea. That essentially tells you when the animal has left the colony, where it's foraged and where it's gone while it's at sea. Put all the foraging tracks together and we can get an idea about where that population of animals is actually feeding at sea.

One of the really incredible things we've found is that no two Australian sea lion colonies are the same. Sea lions on three of the islands specialised in feeding in very shallow, inshore waters that were about 10m in depth. The other three islands were very, very different. The animals on those islands were travelling much greater distances, feeding out into mid to outer continental shelf waters.

This species - I call them the seal of superlatives. Everything about them is amazing. The only non-annual and asynchronously breeding seal, they have the longest gestation period, one of the longest lactation periods and they're really unique - there are no other seal species does things the way that sea lions do. We have no real understanding what the evolutionary pressures, if you like, were that actually shaped this animal. So the more research we're doing into their feeding, into their breeding biology, we're slowly learning what are the critical things that may have shaped this most unusual life history.

Stop smoking!

Mitosis

Meiosis

biology animation (you might actually learn something)

Ecology

Ecology is the branch of Science that deals with the study of interactions between the organisms and their environment. The environment on the other hand is composed of abiotic and biotic components.

The Abiotic Environment

• Air and the different percentage of gases, Atmosphere, Soil and their stratification.

Adaptation

• Any physiological, morphological or behavioural heritable trait possessed by an organism which aids survival or reproduction; Fitness; Natural Selection; Genotype and Phenotpe; Animal and Plant adaptations to the environment.

Population Ecology

• Population and Population Structure Natality, Mortality and Population Growth
• Demography and Life History traits
• Population Limiting Factors: density and density dependence
• Population Dynamics- fluctuations and cycles, Malthus Theory
• Growth of Human Population

Community Ecology

• Community structure and stability Competition: The nature of competition, intraspecific and interspecific competition, Predation, Parasitism, Mutualism, Human interaction between communities, Succession

Ecosystem

• Components of an ecosystem; Ecological Niche; Edge species; Succession
• Nutrient cycling and Biogeochemical Cycles- Nitrogen, Water, Carbon
• Primary and secondary production; Food chain; Food web; Productivity
• Ecological Pyramids

Biomes and Biodiversity

• Levels of Species Diversity(alpha, beta and gamma); Hotspots; Biosphere
• Reserves; Wildlife Parks and sanctuaries

Behavioural Ecology

• Social groups; Cooperation; Altruism and sex in ecology

Modern Ecology

• Pollution( Air, water, soil, noise) and its control, Global Warming, Pest control
• Conservation; Endangered Species; IUCN

Evolution

The term “evolution” in biology encompasses all the changes that have transformed life from its earliest beginnings to the diversity that characterizes it today. Charles Darwin, recognized as Father of Evolution presented a convincing case for evolution in his book “The Origin of Species” by threading together an overwhelming array of unrelated facts.

The Origin of Life and Chemical Evolution

• Theories of Evolution
• Pre-requisites for the origin of life
• Oparin Haldane Theory
• The first living cell ( protocells and microspheres)
• Lipid membranes, RNA world
• Urey-Miller’s experiments and stromatolites.

Natural Selection and Adaptation

• Lamarckism
• The Darwinian Revolution
• Neo-Darwinism, and Adaptation.

Species and Speciation

A species is a group of reproductively isolated organisms which can potentially interbreed among themselves

• Modes of speciation
• Types of species

Mechanism of Evolution

• Genetic variability in populations natural selection and reproductive isolation are the three major factors responsible for evolution. Variations, Mutations Polymorphism

Population Genetics

• Concept of gene pool
• Hardy-Weinberg Equilibrium
• Bottleneck Effect
• Genetic Drift or Sewall Wright Effect
• Artificial Selection

Evidences in Favour of Evolution

• Homology and Analogy
• Divergent and Convergent Evolution
• Evidences from embryology, palaeontology, biogeography, cytological and genetic evidences.

Extensions and Modifications of Mendel's

Molecular Evolution

• Concept of Biological Clock
• Phylogenetic trees
• Cladogram and Evolutionary relationships

Gentics

Life, since it appeared some 3.5 billion years ago, is still continuing and also undergoing gradual change that mailny results from sexual reproduction. Sexual reproduction combines the traits of the two parents in the offspring and also contributes to the evo- lution of the species. How these traits are transmitted forms the core of genetics.

A Brief History of Genetics

Although the science of genetics has developed only in the last decade, the principles of heredity have been understood and applied in the domestication of plants and animals, which began approximately 10,000 and 12,000 years sgo. Examples include the modern wheat and the artificial pollination of date palms.

Early theories of Heredity

Since the earliest times, many theories were put forward that sought to explain in what physical form the traits are passed on from the parent to the offspring. Blending Inheritance. E.g Preformation Theory, Particulate Theory,These are called Theories of Theory of Pangenesis.

The Rise of Genetics

Developments in cytology in the 1800s such as the concept of Cell Theory(Schwann and Schleiden) had a strong influence on genetics. Several cytologists demonstrated that the nucleus had role in fertilization. August Weissman proposed the Germ Plasm Theory which held that the cells in the reproductive organs carry a complete set of genetic information.

Mendelian Genetics

Johann Gregor Mendel, the Father of Genetics conducted experiments on the pea plant Pisum sativum and gave the two basic principles of Inheritance: Principle of Segregation and the Principle of Independent Assortment; Monohybrid Cross and Dihybrid Cross.

Genetic Crosses and Analysis

Monohybrid and Dihybrid Cross; Test Cross; Back Cross; Reciprocal Cross; Genetic Symbols and Terminology; Pedigree analysis and Punnett Square Application of probability: Multiplication Rule and Addition Rule

Chromosomes and Genetics

The characteristics that are transmtted from one generation to another were called "factors" by Mendel and renamed as "genes" by Johannsen in 1909. Walter Sutton in 1902 proposed that genes are located on chromosomes. These genes are the actual physical hereditary units that are located on the chromosomes in a linear order. Because eukaryotes possess multiple chromosomes( they are diploid), mechanisms exist to ensure that each new cell recieves one copy of each chromosome. Cell Division- Mitosis Genetic Recombination-Meiosis Homologous chromosomes and sister chromatids Movement of chromosomes on the spindle fibres Prokaryotic Cell Reproduction, e.g Binary fission Eukaryotic Cell Reproduction, Cell cycle Chromosomes as the carrier of Hereditary traits Chromosomal explanation of Mendel's Principles

Extensions and Modifications of Mendel's

Principles

After Mendel laid down the basic principles of heredity, biologists began to apply these principles to organisms other than peas, and it quickly became apparent that many characteristics do not follow these principles. Codominance Incomplete Dominance Multiple Alleles Epistasis Lethal genes Cytoplasmic Inheritance Maternal Effect Anticipation Polygeny and Pleiotropy Genomic Imprinting

Sex and Inheritance

The term "sex" in genetics refers to sexual phenotype. Most organisms have only two sexual phenotypes: Male and Female. The sex of an individual organism is defined in terms of its phenotype and the mechanism by which sex is established is called "sex determination" Sex Chromosomes Sex determination in fruitfly and humans Sex linked inheritance Dosage Compensation Sex influenced and Sex limited characteristics

Linkage

Genes that are located on the same chomosome or very close to each other do not strictly obey Mendel's Principle of Independent Assortment; rather they tend to be inherited together just like two closely tied knots on a string. Such genes are said to be linked and to understand their mechanisms, it is crucial to make the conceptual connection between genotypes in a cross and the behaviour of chromosomes in meiosis. Notations, Complete and Incomplete Linkage Linkage as revealed by a test cross Coupling and Repulsion Physical basis of recombination Introduction to genetic maps.

Multicellularity: Structure and Function in Animals

Levels of Structural Complexity

Within the multicellular animal body, there are different levels of structural organization. The lowest level is chemical in which atoms combine to form molecules. The cells are the smallest independent units and each cell type has become specialised to carry out a particular functionthat contributes to the body needs. The next in the hierarchy is the tissue, the organs and then the organ system.

The Internal Environment and Homeostasis

The internal environment is the water based medium in which the body cells exist. The composition of this internal mileu is maintained within narrow limits and this fairly constant state is called Homeostasis. Feedback mechanisms Physiological Variables Thermoregulation

Animal Tissues

The tissues of the body consist of a large number of cells and they are classified according to the size, shape and function of these cells. Classification of Animal Tisues - Postion, origin, structure and function Epithelial Tissues, Connective Tissue, Muscle Tissue, Nervous Tissues Membranes Glands Tissue Regeneration]

Intake of Raw Materials: Animal Nutrition

A nutrient is any substance that is digested, absorbed and utilised to promote body function. These maybe carbohydrates, proteins, fats or vitamins.
Nutrition: Autotrophic and Heterotrophic nutrition; modes of nutrition; process of nutrition.
Feeding mechanisms in Animals
Digestion, Organs of the Digestive system/Alimentary canal.
Digestive system of Man: Basic structure, mouth, teeth, salivary glands,pharynx, oesophagus, stomach, intestine, associated organs Metabolism of carbohydrates, proteins and fats. Balanced diet, Nutritional Requirements, Disorders of Nutrition

Transport and Communication

Transport systems ensure that all cells have access to the internal and external environment. The blood, the circulatory system and lymphatic system are involved. All communication systems involve receiving, collating and responding to appropriate information.

Circulation

Transport Systems: Principles, transport system in invertebrates
Blood: components
Circulatory Systems: Heart(structure and pumping action), cardiac cycle, double circulation, blood vessels, blood pressure
Lymphatic System: Lymph vessels and lymph nodes, Role in immunity Disorders of Cardiovascular and Lymphatic Systems.

Gas Exchange and Transport

The cells of the body need energy for their chemical activity that maintains homeostasis. Most of this energy is derived from chemical reactions that take place only in the presence of oxygen. The respiratory system provides the route by which the supply of oxygen present in the atmospheric air gains entry into the body and it also provides the route for the excretion of carbon dioxide.

• Aerobic and Anaerobic Respiration
• Basic characteristics of Respiratory Organs
• Respiraory organs in different animals
• Human respiration: organs, mechanism of respiration, Pulmonary ventilation, External Respiration, Respiratory centers in the brain,
• Respiratory pigments: Transport of O2 and CO2, Bohr Effect
  

Communication and the Nervous System

The Nervous System detects and responds to changes inside and outside the body. Organisation of the nervous system and tissues within the body enables rapid comminication between different parts of the body.

• Organization: Central Nervous System, Peripheral Nervous System and Autonomic Nervous System; Organization in different animals.
• Neurons, Nervous tissue and histology of the Nervous System
• The Vertebrate Brain: Cerebrum, Cerebellum, Brain stem, Spinal Cord, Grey and white matter, Reflex Arc
• Peripheral Nervous System: Spinal nerves and Cranial Nerves.
• Autonomic Nervous System: Sympathetic and Parasympathetic counterparts, effects.
• Neural Signals: Membrane potentials and Action Potentials, Ion channels All or none response, Propagation and conduction of nervous impulse, Neurotransmitters
• Sensory Reception: Principles Ear, structure and physiology Eye, structure, physiology, adaptation, accomodation Sense of smell, taste and touch
  
  

Endocrine System

The Endocrine System consists of glands widely separated from each other with no direct anatomical links that secretes hormones/chemical messengers into the blodstream. Together with the Nervous system, it controls important aspects of body function and maintains homeostasis.

• Exocrine and Endocrine Glands
• Hormones: Their chemical nature, mode of action, types and general effect
• Mammalian Endocrine System: Structure, function and disorders.
• Hypothalamus
• Pituitary
• Thyroid
• Parathyroid
• Thymus
• Adrenal Glands
• Pineal
• Pancreas
• Ovaries, testes, Placenta and others

Plant Diversity

Kingdom Monera

The group "Prokaryotes" includes the most ancient, the smallest, the simplest and the most abundant prokaryotes. The term prokaryote means "before a nucleus". Fossil records indicate that the prokaryotic organisms oroginated about 3.5 billion years ago and were alone on Earth for about 2 million years. Thus these evolved before the eukaryotes.
Classification:

• Bacteria
• Spirochaetes
• Actinomycetes
• Rickettesiae
• Mycoplasma
• Cyanobacteria
• Archaebacteria

• Discovery, General Characters Gram positive and Gram Negative Bacteria Structure of Bacterial/ Prokaryotic Cell Bacterial Reproduction( Asexual and Sexual): Conjugation, Transformation,Transduction, Lytic and Lysogenic Cycles Motility: Cilia and Flagella Prokaryotic Lifestyles: Habitats and Modes of Nutrition Pathogenic Prokayotes Ecological and Economic Importance of Prokaryotes Bacterial Culture and Growth

Unicellular Protists

• Protists Systematics and Phylogeny General Characters of Protists: Habitat, General Structure Locomotion: Pseudopodia, Cilia, Flagella Reproduction in Protists Life Cycles of Protists: Zygotic meiosis, Gametic meiosis Diversity of Protists: Structure, Important characters and importance

Photogenic Protists Diatoms Euglenoids, Flagellates Slime Moulds Zooflagellates. e.g. Trypanosoma Sporozoans. e.g. Plasmodium Ciliates. e.g. Paramaecium

Algae

The group Algae includes the most primitive plants with chlorophyll amd a simple thalloid body that is not differentiated into root, stem and leaves.
General Characters Classification: Red Algae, Brown Algae, Green Algae Important Characters, Life Cycles Economic Importance

Fungi

Fungal Structure and Nature of growth Habitats and modes of Nutrition Reproduction in Fungi: Sexual, Spore formation Diversity of Fungi

• Division Chytridiomycota
• Division Zygomycota
• Division Ascomycota
• Division Basidomycota

• Moulds, Yeasts, Lichens and Mycorrhiza Ecological Impacts of Fungi: Decomposers, Symbionts, Pathogenic Nature
  
  

Plant Diversity

Plant Evolution

Origin of Land Plants, Modernization of Land Plants, Evolution of Seeds

Bryophytes

The Division Bryophyta includes the simplest and the primitive land plants. They occupy a position intemediate between Algae and Fungi

• The Gametophyte and Sporophyte
• Alternation of Generations
• Classification of Bryophytes Liverworts, Mosses and Hornworts
• Economic Importance of Bryophytes

Vascular Plants

Origin of Vascular Plants Pteridophytes and seedless Vascular Plants: General Characters, Adaptations to Land Conditions Classification of Vscular Plants: Pteridophytes, Gymnosperms and Angiosperms

Gymnosperms

Development of Seed Habit: Heterospory(microspores and megaspores) Cycads and Conifers, Life Cycle of Pinus Economic Importance of gymnosperms

Angiosperms

• Characteristics of Angiosperms
• Development of flower and fruit habit
• Evolution of Angiosperms
• Diversity: Habitat, modes of Nutrition Monocots and Dicots
• Economic Importnace of Angiosperms

Biology Tutoring

Biology Topics

* Plant Diversity
* Animal Biology
* Classical Genetics
* Evolution
* Ecology

Biostatistics

Topic10. Analysis of covar.pdf	07/26/2005
Topic08. Simple linear reg.pdf	07/26/2005
Topic11. Estimation of sample size.pdf	07/26/2005
Topic03. Intro probability.pdf	07/26/2005
Topic07. Multiple comparisons.pdf	07/26/2005
Topic05. Normal distr.pdf	07/26/2005
Topic04. Discrete probability.pdf	07/26/2005
Topic09. Multiple regression.pdf	07/26/2005
Topic06. Analysis of differences.pdf	07/26/2005
Topic01. Review of math notations.pdf	07/26/2005
Topic02. Descriptive stats.pdf	07/26/2005

Source: Ykhoa.net

Biology

From Wikipedia, the free encyclopedia

Biology studies the variety of life (clockwise from top-left) E. coli, tree fern, gazelle, Goliath beetle

Biology (from Greek: βίος, bio, "life"; and λόγος, logos, "speech" lit. "to talk about life"), also referred to as the biological sciences, is the scientific study of life. Biology examines the structure, function, growth, origin, evolution, and distribution of living things. It classifies and describes organisms, their functions, how species come into existence, and the interactions they have with each other and with the natural environment. Four unifying principles form the foundation of modern biology: cell theory, evolution, genetics and homeostasis.

Biology as a separate science was developed in the nineteenth century, as scientists discovered that organisms shared fundamental characteristics. Biology is now a standard subject of instruction at schools and universities around the world, and over a million papers are published annually in a wide array of biology and medicine journals.^[1]

Most biological sciences are specialized disciplines. Traditionally, they are grouped by the type of organism being studied: botany, the study of plants; zoology, the study of animals; and microbiology, the study of microorganisms. The fields within biology are further divided based on the scale at which organisms are studied and the methods used to study them: biochemistry examines the fundamental chemistry of life; molecular biology studies the complex interactions of systems of biological molecules; cellular biology examines the basic building block of all life, the cell; physiology examines the physical and chemical functions of the tissues and organ systems of an organism; and ecology examines how various organisms and their environment interrelate.