My Science School

Because of the variety of food sources, more species of butterfly are found in woodlands than in any other habitat.

      Some species of butterfly can be found flying at a low level in shady woodland clearings, while others live high among the treetops. Other species of butterfly live along woodland edges, and in areas where people have cleared forests.

    Some of the examples are The Acadian Hairstreak, the Purple hairstreak, the speckled wood and the comma etc. other examples are the White Admiral, large Tortoiseshell, and the silver-washed Fritillary.

The word ‘temperate’ is used to describe those are as on Earth where temperature is modest.

       The wide variety of flowers in grassland and woodland clearings means that there are plenty of butterflies.

     The caterpillars of grassland butterflies feed on grass found in meadows, and heath lands. There are many varieties of grassland butterflies. Most popular among them are meadow brown, the Aphrodite, the purple shot copper, the Adonis blue etc. the wall butterfly is another grass feeding species commonly found in Europe, Asia and Africa.

The butterfly super family known as Papilionoidea consists of five families. They are named Papilionoidea, pieridae, Lycaenidae, Riodinidae, and Nymphalidae. In other words, all the butterflies except skippers come under this super family.

      The Papilionoidea family members are collectively known as swallowtails. Butterflies in the Pieridae family are whites, orange tips, brimstones and sulphurs. The majority of them are either red or brown or blue in colour.

     The third family, Lycaenidae, is the largest family of all with some 6000 or more species. They are mostly found in tropical areas, but they can be seen in other parts of the world too.

     The fourth sub family Nymphalidae is also very large, like the third subfamily with more than 6000 species.

Although butterflies are one of the most widely studied insect groups, there is no uniform method to classify them.

        The Symposium of the Royal Entomological Society of London subdivided butterflies into two super-families – the Hesperioidea and the Papilionoidea.

       The first group that is the Hesperioidea has only one family. Skippers as they popularly known, are very good fliers. They are called so because of their ability to fly very fast. They are very similar to moths. Many skippers are dull in colour, like moths. Their larvae feed on a lot of food plants. They rest as pupa in the cocoon, where pieces of dried up leaves are mixed.

Some butterflies have physical defenses. This behavior is common among caterpillars in temperate countries. An example of such a caterpillar is the Nymphalis. If somebody disturbs such caterpillars, they react in unison by lifting their heads up, and thrashing them from side to side to display anger. This method is useful in scaring smaller predators.

      Spines are also an important part of butterflies’ that they use to defend themselves from other wasps and flies. Aposematism or denoting colouration or markings that serves to warn the markings that serves to warn the predators is another good way to frighten away enemies

        The common Mormon of India has female morphs which imitate the unpalatable red-bodies swallowtails, the common rose, and the crimson roes.

Some butterfly species mimic their neighboring poisonous species to ward off the predators. They often mimic their neighboring species by copying the latter’s colour pattern, along with producing an unpleasant smell and taste.

        Birds and other predators that are familiar with the warning patterns or bright colours of the harmful species mistake these imitator butterflies for their harmful counterparts and go away.

        One such species of butterflies which is good at mimicking is the Ecuador small postman butterfly, which imitates its equally poisonous rainforest neighbor the Ecuador postman butterfly.

Butterflies feed primarily on nectar from flowers. They suck nectar and other liquids through a small pipe under their heads. This small pipe is called ‘proboscis’. They sip water from damp patches for hydration, and feed on nectar from flowers to obtain sugar for energy.

       Some butterflies get nourished by pollen, tree sap, rotting fruit, dung, and dissolved minerals in wet sand, or dirt. Butterflies are pollinators for some species of plants.

      Usually, they do not carry as much pollen load as bees. However, they are capable of transporting pollen over a great distance.

       Some butterflies visit only certain flowers, and avoid others. This phenomenon is called flower constancy. Attracted by the salt in human sweat, sometimes butterflies even land on people.

Puberty is often a time of rebellion, in which familiar things, such as rules in the family, are questioned. Due to hormonal changes in the body, young people undergo emotional instability. Friends and people of the same age become very important. They are torn between being the glamour of being independent and the risk of leaving a secure life. Unfortunately, at this time peer pressure poses a grave danger of getting into conflicts and addictions—such as alcohol or drugs.

 

Girls also undergo a voice change, but it is not as pronounced as in boys. The larynx in the throat is responsible for the voice and the vocal cords are present inside it. In children, the vocal chords are short, so that the voice is rather shrill. During puberty, the larynx grows rapidly in boys and one can clearly see it, the ‘Adam’s apple’, in the centre of the throat.

Continue reading "Do only boys undergo a voice change? "

The production of sex hormones results in the growth of breasts in girls, a broadening of the hips, and the start of menstruation. In case of boys, the body becomes more muscular, testes and penis increase in size, the production of semen starts, and the night ejaculations begin. This is the time for first loves and understanding sexual orientation. A lot of activity goes on in the brain too. New nerve paths arise, and old ones disappear. 

Puberty starts at about 11 or l2 years of age for girls and around 13 years for boys. This is a phase of development, in which the body and the mind undergo a change. Growth spurts, the production of sex hormones start, girls experience their first menstruation, and boys experience the breaking of their voices. Boys and girls start discovering their own sexuality and emotions run high. The transition from childhood to the adult phase is a special time and has different meanings in different cultures.

 

The causes of disabilities are many and cannot always be explained. We do know that a lack of oxygen at birth can cause damages to the brain. If the mother smokes or takes drugs during pregnancy, it can have serious consequences because the drug reaches the blood circulation of the child via the umbilical cord. Sometimes, there may be genetic changes which may cause disabilities. For instance, a change in the 21st chromosome causes Down syndrome in the child. It is important to ensure that people with disabilities are not discriminated against in our society. 

A baby does not need to breathe in the uterus. Everything that it needs for its growth is provided to it by its supply line: the umbilical cord. This cord connects the blood circulation of the child with that of the mother. The foetus, as the unborn child is called, gets nutrients and oxygen through the umbilical cord. The waste products of the foetus are thrown out into the blood circulation of the mother and are excreted by the mother. After the birth of the baby, the umbilical cord is no longer required and is cut off. 

The sex of the baby is determined by the chromosomes. Usually, all of us have 23 pairs of chromosomes. They determine how our body looks like and how it works. They are also the reason we resemble our parents. The 23rd pair of chromosomes is different in case of males and females. In a woman, these are two X chromosomes, in a man it is one X and one Y chromosome. The egg cell has an X chromosome; the sperm could have either an X or a Y chromosome. If a sperm with a ‘Y’ chromosome fertilizes the egg, then the chromosome combination for the baby would be XY: a boy. If an ‘X sperm’ fertilizes the egg, the result is XX: a girl. It is clear, therefore, that the sex of the baby is determined by the father.

 

A new life can start with the fusion of the sperm and the egg, which contains the genetic information of the father and the mother in equal parts. On the way through the fallopian tube, the egg cell divides several times. It finally gets lodged in the mucous membrane of the uterus, a special hollow muscle. This has a good blood supply and provides the egg cell with nutrients. After it is fixed in the uterus, the egg cell is called an embryo and development starts immediately.