Q1. How does ADIS effect human system ? list two possible ways by which it can pass on from one effected person to another ?
Q2. Write three distinguishing feature of phylum echinodermata.Give one example .
Q3. Explain why :
a) A camel walks easily on a sandy surface than a man inspite of the fact that a camel is much heavier than a man .
b) A sharp needle pierces the wood easily but not a blunt knife although the force applied on both is same .
Q4. Represent graphically :
a)two sound waves with same amplitude but different frequency .
b)two s ound waves with different amplitude and same frequency .
Q5. If bromine atom is available in the form of two isotopes 79 Br35 ( 49.7%)and 81Br35(50.3%) calculate the average atomic mass of bromine atom .
Q6. The chemical formulae of bicarbonate of metal ‘M’ is MHCO3 write the chemical formulae of its chloride , sulphate and supplied ?
Q7.
a) Draw a labelled digram for alpha particles scattering experiment.
b) How was it shown that atomic nuclei are positively charged ?
Q8. Write one point difference each, between the following :
(a) Annelids and Arthropods.
(b) Thallophytes and Pteridopohytes.
(c) Poriferans and coelenterates.
Q9.
(a) Distinguish between chronic and acute diseases.
(b) What is inflammation ? Write the symptoms of this in human body.
Q10. What is binomial nomenclature ? Who introduced it ? Why is a scientific name given to each organism ?
Q11. You are been provided with two hollow pipes, a table aside wall, a white sheet, pencil and an alarm clock. Write an activity to study laws of reflection of sound waves using the given materials.
Q12. Names the characteristics of sound which help to distinguish between :
a) Male and female voice
b) Woman and girl child
c) Two friends
Q13. Sound from source A has half the frequency of sound from source B.Define wavelength and compare the wavelength of sound from the two sources .
Q14. Account for the following :
A) Tractors have broad tyres .
B) Relative density has no unit .
C) Density of a liquid affects buoyancy .
Q15. A) Define topsoil ? State its significance .
B) How the soil gets polluted .
Q16. Rohit’s father uses the shaving foam regularly . Rohit used this foam to make clouds on the school stage during a programme .
Answer the following questions :
a) Was Rohit right or wrong ?
b) Explain giving reasons why should Rohit be choosy while using these ?
Q17.
(a) Define the following terms :
(i) Atom
(ii) Molecule
(iii) Polyatomic ion
(b) Identify from the following tetra-atomic and penta-atomic molecules :
CH3OH, CH4, H2O2, PCI5
Q18.
(a) Which organism is more complex and evolved among bacteria, mushroom, and mango tree. Give reason.
(b) List out three common feature in cat, rat and bat.
Q19.
(i) How do frequency and amplitude affect a musical sound ?
(ii) If the amplitude of a wave is doubled, what will be the effect on its loudness?
Q20. Explain how human ear works in the transmission of sound wave to the brain?
Q21.
(a) Why do terrestrial life-forms require fresh water and not saline water?
(b) Draw a schematic labelled diagram of the water cycle in nature.
1. AIDS is a disease caused by HIV infection which damages the immune system of an organism. It is a communicable disease and transmits by following ways:
- Transfusion (transferring blood from one person to another) of HIV+ blood causes HIV infection to the healthy person.
- Use of HIV infected instruments like syringes, needles, surgical and dental instruments spread the disease.
- HIV infected mother spreads the disease to her child during pregnancy.
- The body fluids like semen, blood, secretion of uterus contains high amount HIV. Direct contact (having sexual relationship) with these fluids causes HIV.
2. Features of Phylum Echinodermata:
- Body is radially symmetrical.
- They have well developed water vascular system.
- They use tube feet for locomotion
- Their body is covered by calcareous exoskeleton.
- They are exclusively marine
E.g. Starfish, sea urchin
9. a)
Chronic Disease | Acute Disease |
This disease lasts for a long period of time. | It lasts for a short period of time. |
Slow growth of symptoms. | Extremely severe, dangerous and grow fast. |
Chronic health effects are irreversible. | Acute health effects can be reversed. |
It can be controlled by medicines but not cured totally. | It can be cured by applying medicines. |
Example – Diabetes, kidney problems, cancer. | Example – influenza, measles, throat sore |
b) Inflammation is the response of a body tissue against any harmful pathogen, injury, irritation or wound. The signs of inflammation are swelling, pain, redness, heat etc. It is the first step of self protection provided by our immune system.