Right or Wrong Science 1 Trivia Quiz

Answer: false

Eutrophication is one of the various harmful effects of overuse of chemical fertilisers. The term 'eutrophic' means 'well-nourished with nutrients'. Thus, eutrophication refers to the enrichment of water bodies by inorganic plant nutrients like phosphates and nitrates. This process speeds up to due to the use of chemical fertilisers.

Chemical fertilisers are man-made plant nutrients that are prepared artificially in factories. However, they do not provide humus. They change the soil structure and make the soil prone to erosion. Excess of chemical fertilisers also makes the soil too acidic or alkaline, and therefore, unfit for agricultural cultivation.

Chemical fertilisers are non-biodegradable, so when they are used excessively by farmers, a lot gets washed away by rain. Being water-soluble, they run off easily and are carried into nearby water bodies. This leads to the enrichment of the water bodies, which causes an excessive growth of algae.

To prevent this, farmers are advised not to use fertilisers excessively.

Answer: False

Cells are mainly of two types - prokaryotic cells and eukaryotic cells. The word 'prokaryotic' comes from the Greek words 'pro' meaning 'primitive' and 'karyon' meaning 'nucleus'. The word 'eukaryotic' comes from the Greek words 'eu' meaning 'true' and 'karyon' meaning 'nucleus'.

Eukaryotic cells, e.g., cells in the human body, have a well-developed and organized nucleus. In prokaryotic cells, the nucleus is not so well-developed and membrane-bound and organized. The nuclear material in prokaryotic cells is also called the incipient nucleoid. The nuclear material also remains suspended on the cytoplasm of prokaryotic cells.

The cell wall in eukaryotic cells is made of cellulose and hemicellulose. However, the cell wall of prokaryotic cells is made of a substance called peptidoglycan. Membrane-bound cell organellles that are present in eukaryotic cells are absent in prokaryotic cells.

Answer: true

There are mainly two types of mirrors - plane mirrors and curved mirrors.
Curved mirrors are of two types - concave mirrors and convex mirrors. A concave mirror is a mirror that is curved inwards. A convex mirror is a mirror that bulges outwards.

Whenever a parallel beam of light strikes a concave mirror, the rays of light converge and actually meet at a point called the focus of the mirror. So, it is called a converging mirror.

When a parallel beam of light strikes a convex mirror, the rays of light diverge and appear to diverge from a single point also called the focus. Thus, a convex mirror is called a diverging mirror.

The focal length of any curved mirror is always half the radius of curvature. A convex mirror produces a virtual, erect and diminished image of an object.

The nature of the image produced by a concave mirror depends upon the distance of the object from the mirror. If the object is farther from the mirror than the focus, a real and inverted image is produced. If the object is placed within the focal length, a virtual, erect and enlarged image is produced.

Answer: false

Non-metals differ in their reactivities. This is better observed among elements with similar properties, which are said to form a family. For example, the elements fluorine (F), chlorine (Cl), bromine (Br), iodine (I) and astatine (At) form the halogen family.

The halogens are considered to be members of the seventeenth group in the periodic table. The word 'halogen' means 'salt-forming'. The halogens react with metals to form halide salts, e.g., sodium chloride (NaCl) and potassium iodide (KI). In decreasing order of their reactivity, the halogens are as follows - fluorine, chlorine, bromine, iodine and astatine. Fluorine and chlorine are gaseous; bromine is liquid and iodine is solid under normal atmospheric conditions.

Answer: true

When any body tries to move against a surface, a force arises at their point of contact that opposes their motion. This force, called friction, always acts in a direction opposite to the applied force. It is due to friction that a moving body comes to rest. Friction happens due to the irregularities on the surfaces of bodies. It is a contact force.

Friction has several advantages as well as disadvantages. Some of its disadvantages are that it produces heat, wastes energy and causes surfaces to wear out.

Fluids like air or water also cause friction. Whenever any body tries to move through air or water, the medium opposes the motion of the body.

The shapes of cars, aeroplanes and even shops are streamlined as it helps reduce the fluid friction. A streamlined body has smooth outlines. Whenever a streamlined body passes through a fluid, it cuts through it. It disturbs the natural flow of the floods as little as possible. It offers last resistance to the fluids's movement and easily overcomes the resistance posted by the fluid to its motion.

Other ways of reducing friction are polishing, oiling or by placing ball or roller bearings.

Answer: False

Teflon is actually used to make non-stick kitchenware. The molecular composition of Teflon is polytetrafluoroethylene [(C2F4)n].

Polythene is used to make bags, containers, bottles and many other things. The plastic bags we use are actually made of polythene. The molecular formula of polyethylene is (C2H4)nH2.

Both Teflon and polythene are synthetic polymers. They are artificially prepared chemical substances. They are made from the chemical combination of small units called monomers. For example, ethene is the monomer of the polymer polythene.

The word 'monomer' comes from the Greek words 'mono' meaning 'one' and 'meros' meaning 'small units'. The word 'poly', as in 'polymer' means 'many' in Greek.

The synthetic fibres used to make fabric, like nylon, polyester, etc. are also synthetic polymers.

However, synthetic polymers have some disadvantages as well. They are non-biodegradable as a result of which they add to the increasing amount of waste. They choke drains and even kill cows who accidentally swallow them while grazing. Since they are non-biodegradable, the only way to dispose then is incineration, which releases harmful gases. Most of the monomers used for making synthetic polymers are poisonous and can cause cancer.

Answer: true

There are two basic modes of reproduction - asexual reproduction and sexual reproduction. Asexual reproduction requires only one parent while sexual reproduction requires two parents - one male and one female.

Asexual reproduction is common among lower organisms. Asexual reproduction can be classified into five natural methods - binary fission; budding; fragmentation; regeneration and vegetative reproduction.

Budding is common among organisms like Hydra and yeast. Here the parent cell produces an outgrowth called a bud. The bud grows and gets detached from the parent's body to lead its individual life.

Yeast can also reproduce through binary fission; where one parent cell divides into two daughter cells. Yeast can produce buds in chains where the buds do not separate from the parent cells. The parent cell gives rise to one or more buds which in turn produce their own buds.

Hydra is also capable of regeneration; where a broken body part grows into a new individual.

The offspring produced in asexual reproduction have the same genetic traits as the parent.

Answer: true

Sound is produced by the vibrations of a body. The frequency of a vibrating body is the number of vibrations it completes in one second. The pitch of a sound, i.e., how shrill or bass it is, depends upon the frequency of the vibrations. The SI unit of frequency is Hertz (Hz). If the frequency of a vibrating body is 200 Hz, it means it makes 200 complete vibrations in one second.

Humans can hear sounds only within a range of 20 Hz and 20000 Hz. Sounds of a frequency below 20 Hz are called infrasonics, and those of a frequency above 20000 Hz after called ultrasonics. Both infrasonics and ultrasonics cannot be heard by us. Ultrasonic sounds are used in ultrasonography to get a 'sound' image of our various organs.

However, humans can produced sounds within a range of only 60-13000 Hz. A woman produces sounds of higher frequency than a man.

However, the range of sounds produced and heard by other animals are different from those produced and heard by us. Dogs, cats, monkeys, etc. can hear ultrasonics. Dolphins, bats, porpoises and whales can hear as well produce ultrasonic vibrations.

Answer: false

Each planet of the solar system rotates about its axis and revolves around the Sun. The time period taken by a planet to complete one rotation about its axis is called its day.

The time period taken by a planet to complete one revolution around the Sun is called its year. Mercury takes only 87.97 Earth-days to complete one revolution around the sun as it revolves around the sun very fast. However it rotates about its axis at a slow speed. So one day on Mercury is equivalent to 58.646 Earth-days. However Mercury does not hold the distinction of being the only planet where a day is longer than a year.

That distinction goes to Venus! Venus takes only 224.7 Earth-days to complete one revolution around the Sun. But its day is the longest in the solar system. One day in Venus is equivalent to 243 Earth-days!

Both planets do not have a moon.

Answer: true

A computer network is a link between two or more computers. Computer networks can be classified into four types based on the geographical extent covered - PAN (Personal Area Network), LAN (Local Area Network), MAN (Metropolitan Area Network) and WAN (Wide Area Network).

A PAN is a network of computers and devices such as printers our mobile phones, within the proximity of an individual, such as in a room. Out is often used to transfer files between different devices, such as transferring am music file from a computer to a MP3 player.

A LAN is a network of computers and other devices within a building or even a campus. Several scold and offices may contain an entire LAN.

A MAN is a computer network that connected computers and other devices within an entire city. Several companies having various branches all over a city and government offices may use a MAN.

A WAN is a computer network that connects computers and other devices all across the world. International organizations and government offices, banks and ATMs, etc. may use a WAN.