SSC Maharashtra Board Science 2 Question Paper Dec 2020 with Answers

Maharashtra Board SSC Class 10 Science 2 Question Paper Dec 2020 with Answers Solutions Pdf Download.

SSC Science 2 Question Paper Dec 2020 with Answers Pdf Download Maharashtra Board

Time: 2 Hours
Total Marks: 40

Note:

1. All questions must be attempted.
2. Wherever necessary scientifically correct diagrams and correct labelling should be drawn.
3. Start every main question on a new page.
4. Numbers to the right indicate full marks.
5. For Question No.1(A) MCQ marks will be given only for the first attempt.
6. The answer to every MCQ should be written as shown:
   Example – Q. No. 1(A) (i) (b).

Question 1.
(A) Choose the correct alternative from the given options: [5]
i. Water reservoir possesses __________ energy. (D)
(A) Nuclear
(B) Thermal
(C) Kinetic
(D) Potential
Answer:
(D) Potential

ii. In mitotic division, nuclear membrane completely disappear in __________ phase. (C)
(A) Telophase
(B) Prophase
(C) Metaphase
(D) Anaphase
Answer:
(C) Metaphase

iii. Genetic changes occur due to __________ pollution. (A)
(A) Radioactive
(B) Air
(C) Water
(D) Soil
Answer:
(A) Radioactive

iv. In human, sperm production occurs in the __________ organ. (B)
(A) Seminal vesicle
(B) Testes
(C) Prostate gland
(D) Cowper’s gland
Answer:
(B) Testes

v. Which sanctuary of Assam is under threat due to dams and indiscriminate use of water? (C)
(A) Tadoba
(B) Kaziranga
(C) Manas
(D) Sundarban
Answer:
(C) Manas

(B) Answer the following sub-questions as per given instruction: [5]
i.

Name the locomotory organ of animal shown in the above figure.
ii. Find the correct co-relation:
Spirogyra: Fragmentation :: Planaria : __________.
iii. Write whether the following statement is True or False:
DNA fingerprinting is mainly useful in Forensic Sciences.
iv. Write the molecular formula:
4% acetic acid (Vinegar).
v. Which molecules are necessary for the formation of plasma membrane?
Answer:
i. Tu be feet are the lo comotory organ in Starfish.
ii. Re generati on
iii. True
iv. CH₃COOH
v. Phospholipids are necessary for the formation of plasma membrane.

Question 2.
(A) Give scientific reasons (any two): [4]
i. While performing the exercise, we feel tired.
ii. Hydroelectric energy, solar energy and wind energy are called renewable energies.
iii. Microbial enzymes are used instead of chemical catalysts in chemical industry.
(B) Answer the following questions (any three): [6]
i. Distinguish between Aerobic respiration and Anaerobic respiration (any two points).
ii. Write a short note on Sacred groves.
iii. Explain the term:
Modern technology of reproduction IVF.
iv. How is Balanoglossus connecting link between chordates and non-chordates?
v. Explain Darwin’s theory of natural selection.
Answer:
(A) i. a. While exercising the muscle cells perform anaerobic respiration.
b. During anaerobic respiration in muscle cells, lactic acid accumulates in the body.
c. Lactic acid accumulation is a result of the process of fermentation during which glucose is broken down by anaerobic respiration, forming organic acids.
d. Also, the production of ATP is comparatively less during anaerobic respiration.
Hence, a person may get tired on quick exercise.

ii. a. The sources of energy which are being produced continuously in nature and are inexhaustible, i.e., they are always available for use are called renewable sources of energy.
b. Hydroelectric energy, solar energy, wind energy are produced from energy sources like water, sunlight and wind respectively that are produced continuously in nature and will not get depleted.
Thus, hydroelectric energy, solar energy and wind energy are called renewable energies.

iii. Microbial enzymes are used instead of chemical catalysts in chemical industry because:
a. Corrosion is a common problem in chemical industries. Using anti-corrosive instruments increases the production cost. However, while using microbial enzymes costly anti-corrosive instruments are not required.
b. Microbial enzymes are active at low temperature, pH and pressure. Thus, they save energy.
c. Enzymes carry out specific processes due to which unnecessary by-products are not formed. Thus, expenses on purification are minimized.
d. In microbial enzymatic reactions, elimination and decomposition of waste material is avoided and enzymes can be reused. Thus, microbial enzymes are eco-friendly.

(B) i.

Aerobic respiration	Anaerobic respiration
a. It occurs in the presence of oxygen.	It occurs in the absence of oxygen.
b. It occurs via. three steps, namely, glycolysis, TCA cycle and electron transfer chain.	It occurs via. two steps, namely, glycolysis and fermentation.
c. The end products are CO2, H2O and energy.	The end products are organic acids or alcohol and energy.
d. More amount of energy is generated.	Less amount of energy is generated.
e. Complete oxidation of glucose takes place.	Incomplete oxidation of glucose takes place.
f. It takes place in higher plants, animals and certain aerobic microbes.	It takes place in yeast, muscle cells, erythrocytes and some anaerobic microbes.

ii. a. The forest protected or conserved in the name of God (on religious grounds) and considered to be sacred is known as sacred grove or Devrai.
b. Sacred groves are in fact sanctuaries conserved by the society and not by the government forest department.
c. It has special protection, as it has been conserved due to special religious importance.
d. Sacred groves are present not only in Western Ghats of India but in the entire country.

iii.

a. IVF is a technique in which fertilization is brought about in the test tube. Sperm is injected into the ovum using a micropipette.
b. The embryo formed after fertilization is implanted in the uterus of a woman at the appropriate time.
c. Childless couples, who have problems like less sperm count, obstacles in oviduct, etc., can use IVF technique for having a child.

iv. a. Balanoglossus belongs to phylum Hemichordata.
b. It possesses certain characteristics of both Chordates and Non-chordates.
c. Absence of vertebral column or spinal cord and a worm-like body are the Non- chordate like characteristics seen in Balanoglossus.
d. Presence of notochord, pharyngeal gill slits are some Chordate-like characters seen in Balanoglossus.
Hence, Balanoglossus is considered as a connecting link between Non-chordates and Chordates.

v. a. Darwin’s theory of natural selection is based on the concept of survival of the fittest.
b. Organisms can reproduce prolifically.
c. Under limited resources, organisms compete with each other in a life-threatening manner for their survival.
d. According to this theory, only those organisms survive which show modifications for winning the competition. The selected organisms then give rise to new species with their specific set of characters.

Question 3.
Answer any five questions from the following. [15]
i.

Identify and explain the above different types of symmetry.
ii. Write any six factors affecting the social health.
iii. Complete the following chart:

Substance obtained by microbial processing	Roles
(a) Citric acid	__________
(b) Ascorbic acid	__________
(c) Beta carotene	__________
(d) Glycolipids	__________
(e) Vanillin	__________
(f) Xylitol	__________

iv. Explain the three different levels of Biodiversity.
v. Observe the following figure and answer the questions:

a. Identify the process in above figure and after how many days it will repeat again?
b. Write the names of hormones involved in this process.
vi. What are the advantage of hydroelectric power generation?
vii. a. Define vestigial organs.
b. Write name of any two vestigial organs in human body.
c. Explain how one human vestigial organ is functional in another animal.
viii. What will you do in the following cases and why?
a. Child of your neighbour is addicted to tobacco chewing.
b. You have to use free space around your home for good purpose.
c. Your friend has developed the hobby of snapping selfies.
Answer:
i. Based on body symmetry, animals can be classified into three groups:
a. Figure (a) represents organism with asymmetrical body: In this type of symmetry, there is no such imaginary axis of the body through which we can get two equal halves. e.g. Amoeba, Paramoecium, some sponges.
b. Figure (b) represents organism with radial symmetry: In this type of symmetry, if an imaginary cut passes through the central axis of any plane of the body, it gives two equal halves. e.g. Starfish.
In starfish, there are five different planes passing through the central axis of the body, through which we can get two equal halves.
c. Figure (c) represents organism with bilateral symmetry: In this type of symmetry, there is
only one such imaginary axis of the body through which we can get two equal halves. e.g. Insects, fishes, frog, birds, human, etc.

ii. a. The ability of a person to establish relationship with other persons in the society is known as social health.
b. The factors affecting social health are:

1. Mental stress
2. Addiction
3. Incurable diseases
4. Excessive use of modern technology
5. Education and financial status of people.
6. Number of gardens and play grounds in the vicinity.
7. Social and physical conditions of the surroundings.
8. The type of residential area.
9. Provision of water and availability of toilets
10. Political conditions (views)
11. Social treatment of people
12. Social safety
13. Transport facilities
14. Education and job opportunities
15. Fulfilment of basic needs of people including food, clothing, shelter and medicines.

iii.

Substance obtained by microbial processing	Roles
(a) Citric acid	Production of drink, toffees chocolates
(b) Ascorbic acid	Antioxidants and vitamins
(c) Beta carotene	Edible colours
(d) Glycolipids	Emulsifiers
(e) Vanillin	Used as essence
(f) Xylitol	Artificial sweetener

iv. a. Biodiversity is the richness of living organisms in nature due to the presence of varieties of organisms, ecosystems and genetic variations within a species.
b. Biodiversity occurs at three different levels.
1. Genetic diversity: It refers to the occurrence of diversity among organisms of same species. e.g. Each human being is different from other.
2. Species diversity: It refers to the innumerable species of organisms that occur in nature. e.g. Variety of plants, animals and microbes.
3. Ecosystem diversity: It refers to variation in ecosystems present in nature. These ecosystems are formed by the interaction between plants, animals, their habitats and changes in the environment. Each ecosystem has its own biotic (animals, plants, microbes) and abiotic factors.

v. a. The given figure represents menstrual cycle. It will repeat again after an interval of every 28-30 days.
b. Menstrual cycle is controlled by four hormones: follicle stimulating hormone (FSH), luteinizing hormone (LH), estrogen and progesterone.

vi. Advantages of hydroelectric power plant:
a. No fuel is burnt in a hydroelectric power plant. Thus, no air pollution due to combustion of fuel occurs.
b. Electricity can be generated whenever required if the dam has sufficient water storage.
c. During rainy season, the water in the water reservoirs can be replenished and used for power generation.

vii. a. Vestigial organs are degenerated or underdeveloped useless organs of organisms.
b. Vestigial organs in human body: Appendix, muscle of the ear pinna, wisdom tooth and nictitating membrane (third eyelid).
c. Some vestigial organs in humans that are functional in other animals are as follows:
1. Appendix: It is fully functional in ruminants for digestion of cellulose.
2. Muscle of the ear pinna: It is useful in monkeys and other animals like rabbits, cows, horses, etc. for movement of ear pinna.

viii. a. If I find that the child of my neighbour is addicted to tobacco chewing:
1. I will make him aware about the health problems associated with chewing tobacco like mouth cancer, tooth decay, gum diseases, etc. This will help him to make decision about quitting tobacco.
2. I will advise him to reduce the use of tobacco everyday till he finally quits it completely.
3. I will also make him talk to his family or friends regarding the issue, so as to help him get rid of the habit.

b. I will use the free space around my home in the following manner:
1. I will grow small plants and shrubs, which will beautify the surroundings and also help in reducing the carbon dioxide levels.
2. I can also make the space available for parking of public vehicles or starting a small playground, library, etc.

c. If I find that my friend has developed the hobby of snapping selfies:
1. I will warn him to be careful while clicking selfies and to be aware about the surroundings so as to avoid accidents.
2. I will try to persuade him to avoid clicking selfies at every occasion and to rather enjoy the moment with friends and / or family.

Question 4.
Solve any one of the following:
i. a. What is meant by disaster management?
b. Classify the following activities into pre-disaster management and post-disaster management:
(i) Identifying the pro-disaster areas.
(ii) Quick establishment of help centre.
(iii) Participation of preferably local people saved from the disaster in arranging the help to victims.
(iv) Getting special training for disaster management.
c. Complete the diagram:

ii. Observe the figure and answer the following questions:

a. Identify the process given in the above figure.
b. Write the importance of above process.
c. Write any two benefits of Biotechnology.
Answer:
i. a. Disaster management is either averting disasters or making arrangement to face it or at least achieving the abilities to face it.
b. Pre-disaster management:
(i) Identifying the pro-disaster areas.
(iv) Getting special training for disaster management.
Post-disaster management
(ii) Quick establishment of help centre.
(iii) Participation of preferably local people saved from the disaster in arranging the help to victims.

c.

ii. a. The figure represents process of production of edible vaccines.

b. Importance of the process of edible vaccine production:
1. Vaccines produced by biotechnology remain active for longer periods in the body.
2. The potatoes produced by the above process, when consumed raw will help the individual develop immunity against the pathogen.
3. Transgenic potatoes provide immunity against cholera and diseases caused by Escherichia coli.

c. Benefits of Biotechnology:
1. Biotechnology is used in the field of agriculture in order to improve crop variety and yields by techniques such as genetic modification, hybridization, etc.
2. Techniques such as artificial insemination and embryo transfer are useful in animal husbandry to improve quality and/or quantity of animal products like milk, wool, meat, etc.
3. Biotechnology has applications for the welfare of human health in diagnosis and treatment of diseases using vaccines, interferons, antibiotics, etc. Also, gene therapy and therapeutic cloning have application in treating genetic disorders.
4. Biotechnology is used for the manufacture of industrial products, environmental management, food processing, green revolution, white revolution and blue revolution.
5. DNA fingerprinting techniques play an important role in forensic sciences and paternity testing.

SSC Maharashtra Board Science 2 Question Paper with Solutions