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Fossil fuels are obtained from: (a) remains of non-living materials. (b) dead remains of birds only. (c) dead remains of insects only. (d) dead remains of living organisms.

(d) dead remains of living organisms. Fossil fuels are buried flammable geologic deposits of organic substances such as dead plants and animals... View Article

Thallophyta, bryophyta and pteridophyta are called as ‘Cryptogams’. Gymnosperms and Angiosperms are called as ‘phanerogams’. Discuss why? Draw one example of Gymnosperm.

Thallophyta, bryophyta and pteridophyta are called as ‘Cryptogams’ because the reproductive organs of plants in all these three... View Article

Abida and Ramesh were doing an experiment in which water was to be heated in a beaker. Abida kept the beaker near the wick in the yellow part of the candle flame. Ramesh kept the beaker in the outermost part of the flame. Whose water will get heated in a shorter time?

The water in the Ramesh's beaker will heat up in a shorter time. This is because the outermost zone of a flame is the hottest zone in which the... View Article

The underlined words in the following sentences have been jumbled up. Write them in their correct form. (a) Loca is obtained from mines. (b) Umpetlore is a fossil fuel. (c) Rineryfe is a place where various fractions of petroleum are separated. (d) Keenrose is a fuel used in jet crafts. (e) Nutsgilh is an example of inexhaustible natural resources.

(a) Coal is obtained from mines Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been... View Article

Which cell organelle plays a crucial role in detoxifying many poisons and drugs in a cell? (a) Golgi apparatus (b) Lysosomes (c) Smooth endoplasmic reticulum (d) Vacuoles

c) Smooth endoplasmic reticulum It participates in the production of phospholipids, the chief lipids in cell membranes and are essential in the... View Article

Manu was heating oil to fry potato chips. The cooking oil all of a sudden caught fire; he poured water to extinguish the fire. Do you think this action was suitable? If yes, why? If not, why not? In such a condition what should Manu have done?

No. Because water is not suitable for fires involving oil. Oil is lighter than water. When one will pour water on burning oil, it'll settle... View Article

What would happen, if all the oxygen present in the environment is converted to ozone? (a) We will be protected more (b) It will become poisonous and kill living forms (c) Ozone is not stable, hence it will be toxic (d) It will help harmful sun radiations to reach earth and damage many life forms.

b) It will be poisonous and will kill living forms. Ozone is a deadly poison and if all the oxygen were to get converted to ozone, no life on... View Article

Various materials which are obtained from nature are called natural resources. Which of the following is not a natural resource? (a) minerals (b) water (c) soil (d) plastic

(d)Plastic Minerals, water and soil are natural resources, but plastic is a man-made material. So, plastic is not a natural resource Natural... View Article

The system of irrigation wherein water is supplied drop by drop near the roots of plants, is called (a) pulley system (b) drip system (c) sprinkler system (d) lever system

Drip system A type of localized irrigation in which drops of water are delivered at or near the root of plants. In this type of irrigation,... View Article

Choose the incorrect statement about insulin (a) It is produced from pancreas (b) It regulates the growth and development of the body (c) It regulates blood sugar level (d) Insufficient secretion of insulin will cause diabetes

b) It regulates growth and development of the body Human insulin was first synthesised in the year 1975, by Dr Teusche, in Switzerland. Insulin... View Article

Corals are (a) Poriferans attached to some solid support (b) Cnidarians, that are solitary living (c) Poriferans present at the sea bed (d) Cnidarians that live in colonies

d) Cnidarians that live in colonies Cnidarians are specialised aquatic animals that use their body cells especially to trap their prey.... View Article

In human beings, the correct sequence of events during reproduction is (a) gamete formation, fertilisation, zygote, embryo (b) embryo, zygote, fertilisation, gamete formation (c) fertilisation, gamete formation, embryo, the zygote (d) gamete formation, fertilisation, embryo, the zygote

a) Gamete formation, fertilisation, zygote, embryo Reproduction is a biological process by which a living organism gives birth to its own... View Article

Endoskeleton of fishes are made up of cartilage and bone; classify the following fishes as cartilaginous or bony Torpedo, Sting ray, Dogfish, Rohu, Angler fish, Exocoetus

Cartilaginous fishes have skeletons composed mostly of cartilage while bony fish have a skeleton composed mostly of bone. Furthermore, these two... View Article

A physical process in which a substance reacts with oxygen to give off heat is called combustion. (True or False). Also write the false statements in their correct form.

False – A chemical process in which a substance reacts with oxygen to give off heat is called combustion. Combustion is a chemical process... View Article

The proteins and lipids, essential for building the cell membrane, are manufactured by (a) rough endoplasmic reticulum (b) golgi apparatus (c) plasma membrane (d) mitochondria

a) Endoplasmic reticulum The endoplasmic reticulum is of two types on the basis of the presence of ribosomes. If the endoplasmic reticulum... View Article

Choose the correct path of urine in our body (a) kidney → ureter → urethra → urinary bladder (b) kidney → urinary bladder → urethra → ureter (c) kidney → ureters → urinary bladder → urethra (d) urinary bladder → kidney → ureter → urethra

(c) Kidney →ureter→ urinary bladder →urethra Kidneys are bean-shaped structures located on either side of the backbone and are... View Article

Fill in the blanks (a) A total ofnutrients are essential to plants. (b) andare supplied by air to plants. (c) is supplied by water to plants. (d) Soil supplynutrients to plants. (e) nutrients are required in large quantity and called. (f) nutrients are needed in small quantity for plants and are called ____.

(a) 16. Nitrogen (N), Phosphorus (P), and Potassium (K), Calcium (Ca), Magnesium (Mg), and Sulfur (S), Boron (B), Chlorine (CI), Copper (Cu),... View Article

Choose the wrong statement (a) The nature of matrix differs according to the function of the tissue (b) Fats are stored below the skin and in between the internal organs (c) Epithelial tissues have intercellular spaces between them (d) Cells of striated muscles are multinucleate and unbranched

c) Epithelial tissues have intercellular spaces. The nature of matrix differs according to the function of the tissue. Epithelial tissue or... View Article

Find out the wrong statement from the following (a) White revolution is meant for increase in milk production (b) Blue revolution is meant for increase in fish production (c) Increasing food production without compromising with environmental quality is called as sustainable agriculture (d) None of the above

a) White revolution is meant for increase in milk production The White Revolution in India helped in reducing malpractice by traders and... View Article

Which of the following statement(s) is (are) correct? (i) Pyruvate can be converted into ethanol and carbon dioxide by yeast (ii) Fermentation takes place in aerobic bacteria (iii) Fermentation takes place in mitochondria (iv) Fermentation is a form of anaerobic respiration (a) (i) and (iii) (b) (ii) and (iv) (c) (i) and (iv) (d) (ii) and (iii)

c) (i) and (iv) The respiration process can be aerobic or anaerobic. Aerobic respiration occurs in presence of oxygen in mitochondria whereas,... View Article

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