Which of the following is not a cell? (a) Red Blood Corpuscle (RBC) (b) bacterium (c) spermatozoa (d) virus
d) Virus Viruses do not have cells. They have a protein coat that protects their genetic material (either DNA or... View Article
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Which of the following reacts with cold water vigorously? (a) Carbon (b) Sodium (c) Magnesium (d) Sulphur
Sodium Metals like potassium and sodium react violently with cold water. In the case of sodium and potassium, the reaction... View Article
Farmers prefer to grow beans and peas in nitrogen-deficient soils. Give reasons for the following.
Leguminous plants such as peas and beans have Rhizobium. It is a bacterium which resides in their root nodules. It... View Article
Which of the following is not an involuntary action? (a) Vomiting (b) Salivation (c) Heartbeat (d) Chewing
d) Chewing Explanation Chewing is an action which a person performs according to his/ her will and involves skeletal muscles... View Article
What are the causes of water pollution? Discuss how you can contribute in reducing water pollution.
Water pollution can be defined as the contamination of water bodies. Water pollution is caused when water bodies such as... View Article
The locomotory organs of Echinodermata are (a) tube feet (b) muscular feet (c) jointed legs (d) parapodia
a) Tube feet Explanation The organisms belonging to the phylum Echinodermata are exclusively marine.The tube feet are small tube-like projections... View Article
Why does the temperature of a substance remain constant during its melting point or boiling point?
The temperature of a substance remains constant at its melting and boiling points until all the substance melts or boils... View Article
While ________ your teeth, leaving the ________ running may waste several ________ of water. (tap, litres, brushing, washing, drops)
(c) While brushing your teeth, leaving the tap running may waste several litres of water. There are several ways to... View Article
What will happen to ‘pooris’ and ‘unused kneaded flour’ if they are left in the open for a day or two?
The ‘unused kneaded flour’, if left in warm conditions, gets infected by microbes which cause fermentation and spoils the flour.... View Article
The disease caused by a protozoan and spread by an insect is _________. (a) Dengue (b) Malaria (c) Polio (d) Measles
Malaria Malaria Plasmodium, that causes malaria, the pathogen completes its life cycle in mosquito and humans. Malaria is not caused... View Article
Which one of the following diseases is caused by protozoans? (a) Malaria (b) Influenza (c) AIDS (d) Cholera
Answer: a) Malaria Explanation Malaria is a mosquito-borne infectious disease caused by various species of parasitic protozoan microorganisms Plasmodium falciparum, Plasmodium... View Article
what do cfcs stand for name some devices where cfcs are used why cfcs are considered as pollutants
CFCs stands for Chlorofluorocarbons Chlorofluorocarbons are the gases used in electric appliances like air conditioners and refrigerators. CFCs are made... View Article
Although 2 cells called gametes fuse, the product formed is a single cell called the zygote. Justify.
During the process of fertilization, the sperm fuses with the egg cell. The content of the sperm cell is transferred... View Article
Growth of Lichens on barren rocks is followed by the growth of (a) moss (b) ferns (c) gymnosperms (d) algae
a) Moss Explanation The process of community development over time, which involves species in one stage being replaced by other species,... View Article
Write the name of different plant parts in which chromoplast, chloroplast and leucoplast are present.
1. Chromoplast – Flowers and Fruits- (impart red, yellow and orange colour to the plant parts, helps in pollination and... View Article
The thread-like structures present in the nucleus are (a) nucleolus (b) chromosomes (c) genes (d) ribosomes
(b) chromosomes A thread like structures found inside nucleus which contain genes on it is called as a chromosome. Each... View Article
A new species X is introduced in a forest. How is it likely to affect the local species of that area?
Introduction of a new species may affect the existence of local species due to competition.The members of the species may... View Article
Air is necessary for combustion. (True or False). Also write the false statements in their correct form.
True, air contains oxygen and oxygen is a supporter of combustion. Air or oxygen which helps in burning is called... View Article
You are provided with a mixture of petroleum and water. Can you suggest a method to separate the two?
Decantation It is the method used to separate a mixture of petroleum and water. Decantation is the process of separation... View Article
The material which is commonly used for making kitchen containers is (a) PVC (b) Acrylic (c) Teflon (d) PET
(d) PET PET(Polyethylene Terephthalate) is used for making kitchen containers because It is strong, durable, light-weight, non-reactive.It is a crystal... View Article
