Central Institute of Higher Tibetan Studies 2009 CBSE CLASS X - Question Paper

insisting upon ‘sustainable natural resource management’? provide any 3 reasons
27. Study the provided data and ans the ques. subsequent the data.
311
Parental plants F1 (first generation off spring) F2 (offspring of self pollination of F1
cross fertilised &
seeds collected
Male parent 330 seeds sown Out of 44 seeds
always bore and observed 33 seeds
red flowers. gave plants with
Female parent All 330 gave red flowers and
always had red flowers 11 seeds gave plants with
white flowers. white flowers
(i) What is the term for this kind of cross?
(ii) What does the data of the column marked F1 indicate?
(iii) Express the genotype of the (a) parents (b) F1 Progeny and (c) F2 Progeny 5
OR
Study the picture provided beneath and comment on the encircled organisms with respect to
(i) the category according to the food they eat.
(ii) trophic level to which they belong.
(iii) percentage of energy available at their trophic level.
(iv) 2 abiotic components of the ecosystem inhabited by them.
(v) energy used for food
production by the producers.
MARKING SCHEME
PAPER I
312
X - SCIENCE
Q.No. Value Points Marks
part A
1. M and C 1
2. Mercury, Hg 1
3. Being alkaline, it neutralizes the lactic acid current in the milk and prevents its
spoilage. 1
4. (i) Any pair of media from higher refractive index to lower refractive index
say medium two to 1
(ii) Any pair of media from lower to higher refractive index (½+½) = 1
5. To prevent chips from getting oxidised.
6. Alloys have high melting point./ do not oxidise (burn) readily at high temp.
1
7. Tooth enamel is made up of calcium phosphate which gets corroded when the pH
in the mouth is beneath 5.5. Bacteria current in the mouth produce acids by degradation
of sugar and food particles in the mouth after eating. Tooth pastes, which
are bases, neutralise the acid. 2
8. ?? Corrosion 1
?? Black coating : Silver sulphide ½
Green coating : Copper carbonate ½
9. Both are accurate
Resistance R = ½
Also = ½
Both the diagrams show the accurate outcome
10. ?? trend of magnetic field lines ½
?? It shows that the magnetic field is the identical at all points inside the 1

Earning:   Approval pending.