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MARCH 2019

SCIENCE AND TECHNOLOGY PAPER-II

Q. 1. (A) Solve the following questions:

(i) Identify the process shown in the following figure and name it.

(ii) Pranav and Pritee are twins in your class. They belong to ……………………. twins type.

(iii) There is a oil layer on the water surface of river in your area. What will you do?

(iv) Fill in the boxes with the help of the given clue:

Continuous consumption of alcohol and tobacco material………………………………

(v) Find out the correlation:

White revolution : Increase in dairy production : : Green revolution :……………………..

(B) Choose the correct alternative and rewrite the statements :

(i) Somatic and stem cells undergo…………………….. type of division.
(a) Meiosis
(b) Mitosis
(c) Budding
(d) Cloning

(ii) Which of the following is a man-made disaster ?
(a) Earthquake
(b) Flood
(c) Meteoric
(d) Leakage of toxic gases

(iii) In a food chain autotrophic plants are present at the ………………… level.
(a) Tertiary nutrition
(b) Secondary nutrition
(c) Producer
(d) Apex

(iv) …………………………..is a cold blooded animal.
(a) Bat
(b) Snake
(c) Rabbit
(d) Elephant

(v) ……………………….is a connecting link between annelida and arthropoda.
(a) Duck-billed platypus
(c) Lungfish
(b) Peripatus
(d) Whale

Ans. (A) (i) Nuclear fission (chain reaction).

(ii) Pranav and Pritee are twins in our class they belong to dizygotic twins.

(iii) Hydrocarbonoclastic bacteria like pseudomonas spp. and Alcanivorax borkumensis can be used to clear the oil on the water surface of the river.

(iv)

(v) Increase in crop production.

(B) (i) (b) Somatic and stem cells undergo mitosis type of division.

(ii) (d) Leakage of toxic gases is a man-made disaster.

(iii) (c) In a food chain autotrophic plants are present at the producer level.

(iv) (b) Snake is a cold blooded animal.

(v) (b) Peripatus is a connecting link between annelida and arthropoda.

Q. 2. Solve any five of the following questions :

(i) Complete the following chart :

(ii) Draw a neat diagram of the structure of chromosome and label the parts :

(a) Centromere

(b) -arm

(iii) What are the advantages of hydroelectric power generation?

(iv) State any four benefits of animal classification.

(v) State any four objective of disaster management.

(vi) Give scientific reason :

Microbial enzymes are used instead of chemical catalyst in chemical industry.

(vii) Read the following extract and answer the questions that follow :

A liberal view behind the concept of organ and body donation is that after death our body should be useful to other needful persons so that their miserable life would become comfortable. Awareness about these concepts is increasing in our country and people are voluntarily donating their bodies.

Life of many people can be saved by organ and body donation. Blinds can regain their vision. Life of many people can be rendered comfortable by donation of organs like liver, kidneys, heart, heart valves, skin etc. Similarly, body can be made available for research in medical studies. Many government and social organisations are working towards increasing the awareness about body donation.

(a) What is the liberal view behind the organ and body donation?

(b) Name any four organs that can be donated.

Answer

. (i)

(ii) (a) Centromere

(b) -arm Structure of chromosome

(iii) Advantages of hydroelectric power generation are :

1. Since no fuel is burnt in hydroelectric power generation, there is no pollution resulting from combustion of fuels.
2. If there is sufficient water storage in the dam, then it is possible to generate electricity as and when necessary.
3. No fuel is needed, therefore the price of the hydroelectricity will not change if the price of fuel increases.

(iv) Benefits of animals classification are :

1. Animals can be easily identified with great accuracy.
2. Classification helps to understand the habitat of each animal and it’s exact role in the nature.
3. It gives idea about animal evolution.
4. Study of animals becomes convenient.
5. Classification helps to understand various adaptations shown by them.

(v) Objective of disaster management are :

1. Rehabitant disaster victims.
2. Supply of essential commodities of the people to reduce the effect of disaster.
3. To restore the human life in the region by creating reconciliation in disaster.
4. Disposal of human life suffered by human being during the calmity and release of the people.

(vi) Microbial enzymes are used instead of chemical catalyst in chemical industry because :

1. Microbial enzymes are active at low temperature, and pressure; due to which energy is saved and erosion-proof instrument are also not necessary.
2. Enzymes carry out specific processes, hence unnecessary by products are not formed due to which expenses on purification are minimised.
3. Elimination and decomposition of waste material is avoided and enzymes can be reused. Hence, such enzymes are ecofriendly.

(vii) (a) 1. Life of many people can be saved by organ and body donation.

1. Similarly, body can be made available for research in medical studies.

(b) The organs that can be donated are liver, kidneys, heart, heart valves, skin, eyes etc.

Q. 3. Solve the following questions. (Any five)

(i) Answer the following questions:

(a) What do you mean by central dogma?

(b) What is transcription?

(c) What is meant by triplet codon?

(ii) Complete the following chart and state which process of energy production it represents :

(iii) (a) Playing games on mobile while eating is right or wrong, justify.

(b) What do you conclude from the following picture?

(c) Observe the following picture and state what can be the outcome?

(iv) Observe the diagram and answer the questions :

(a) Which energy is generated from the power plant?

(b) State its source.

(c) Which is more ecofriendly – Power generation from coal or power generation from natural gas? Why?

(v) Identify my class/phylum and give one example of it :

(a) I have mammary glands and exoskeleton in the form of hair.

(b) We form the highest number of animals on the planet. We have bilateral symmetry and our exoskeleton is in the form of chitin.

(c) I live in your small intestine, my body is long and thread like and pseudocoelomate.

(vi) Observe the following figure and answer the questions :

(a) Identify the process shown in the figure.

(b) Explain the process in short.
(vii) (a) What is biotechnology?

(b) Explain any two commercial applications of it.

Answer.

(i) (a) Information about protein synthesis is stored in the DNA and synthesis of appropriate proteins as per requirement is necessary for body. These proteins are synthesised by DNA through RNA. This is called central dogma.

(b) The process of RNA synthesis is called as transcription.

(c) The code for each amino acid consists of three nucleotides. It is called as triplet codon.

(iii) (a) Playing games on mobile while eating is wrong because it affects the proper digestion of food due to lack of concentration on eating which results into less secretion of digestive juices.

(b) The picture shown in the question is about the no smoking and addiction control.

(c) In this picture the person become selfiecide in which person is not aware about the world around and the risk of accident increases, which may be fatal and he may lose his life.

(iv) (a) Electrical energy is generated from the power plant.

(b) Source is natural gas.

(c) Power generation from natural gas is more eco-friendly because natural gas does not contain sulphur so burning results in less pollution.

(v) (a) Phylum-Chordata

Class-Mammalia

Example-Human, bat, dolphin, elephant and kangaroo.

(b) Phylum – Arthropoda

Example – Crab, spider, scorpion and millipede

(c) Phylum – Aschelminthes.

Example – Ascaris (Intenstinal worm), filarial worm (Loa loa) (Eye worm)

(vi) (a) Modern Landfill Site.

(b) 1. Degradable waste being accumulated is used for this purpose.

1. Large pits are dug in open spaces far away from the residential area and those pits are lined with plastic sheets as a precaution against pollution of soil due to leaching of toxic and harmful materials.
2. Compressed wastes is dumped in the pit. It is covered with the layers of soil, saw dust, leafy waste and specific biochemicals.
3. Bioreactors are mixed at some places. Microbes present in the soil and other top layers decompose the waste.
4. Completely filled pit is sealed with soil slurry.
5. Best quality compost is formed after few days.

(vii) (a) The technique of bringing about improvements in living organisms by genetic modifications and hybridisations, for the welfare of human beings is called ‘Biotechnology.

(b) Commercial Applications of Biotechnology :

1. Crop Biotechnology : Biotechnolgy is used in agricultural field to improve yield and variety like production of hybrid seeds in which genes of two different crops are recombined to form hybrids of various crops. This is especially usefull for fruits.
2. Human Health : Biotechnology helps to identify the role of gene, if any, in disease of a person. Diagnosis of diabetes and heart diseases has become possible even before the onset of symptoms, with the help of biotechnology. Diagnosis of the diseases like, AIDS, Dengue can be done within few minutes. Hence, treatment can be done at the earliest.

Q. 4. Solve any one of the following questions:

(i) (a) Identify the following symbols and state their significance :

(i)

(ii)

(b) How can biodiversity be conserved ?

(ii) Answer the following questions :

(a) “Gender of child is determined by the male partner of couple.” Draw a diagram explaining the above statement.

(b) Prepare a slogan for campaign against female foeticide.

(c) In the following figure, explain how new fungal colonies of mucor are forme

Answer.

(i) (a) (i) This sign indicates ‘Save Water’. We should conserve the water as it is precious.

(ii) This sign indicates ‘Save fuel’. We must save fuel because fuel is a limited resource.

(b) Biodiversity can be conserved in the following ways :

1. Obeying the rules.
2. Conserving all plants and animals.
3. Project for conservation of special species.
4. Maintaining records of the traditional knowledge.
5. Protecting rare species of organisms.
6. Establishing national parks and sanctuaries.

(ii) (a)

Sex determination in human beings.

1. The chromosome number in germ cells producing the gametes are diploid i.e., . It includes 22 pairs of autosomes and 1 pair of sex-chromosomes i.e., or .
2. These germ cells divide by meiosis.
3. Due to this, gametes contain only haploid ( ) number of chromosomes i.e., or .
4. Two types of sperms are produced as or whereas oocytes are produced of only one type as .
5. Both, sperms and oocytes are produced by meiosis.
6. In case of sperms, process of meiotic division is completed before the sperms leave male reproductive tract.
7. However, in case of oocytes, process of meiotic division completes after ovulation; during fertilisation in oviduct.

(b) “Female foeticide is suicide, save the girl child and insure the future”.

(c) Fungi have sporangia. Once the spores are formed, sporangia burst and spores are released. Spores germinate in moist and warm place and new fungal colony is formed.

(d) In the given figure asexual reproduction through spore formation is represented.