10th Science Part 2 July 2025 Board Exam Question Paper with Solutions

Question 1

(A) Choose the correct alternatives:

(i) Our muscle cells perform __________ type of respiration during exercise.

• (A) Aerobic
• (B) Anaerobic
• (C) Fermentation
• (D) Krebs Cycle

Answer: (B) Anaerobic

(ii) Which of the following animals can regenerate its broken body part?

• (A) Cockroach
• (B) Frog
• (C) Sparrow
• (D) Starfish

Answer: (D) Starfish

(iii) Government of India has encouraged the __________ for improving the productivity by launching NKM-16.

• (A) Apiculture
• (B) Cultivation of medicinal plants
• (C) Pisciculture
• (D) Fruit processing

Answer: (C) Pisciculture (Note: NKM-16 usually refers to the Neel Kranti Mission/Blue Revolution).

(iv) At the district level __________ is responsible for disaster management and implementation of rehabilitation schemes.

• (A) Collector
• (B) Tahsildar
• (C) Education Officer
• (D) Chief Executive Officer

Answer: (A) Collector

(v) __________ of West Bengal is reserved for tigers.

• (A) Manas National Park
• (B) Western Ghat
• (C) Molai Jungle
• (D) Sundarban National Park

Answer: (D) Sundarban National Park

(B) Answer the following questions:

(i) State whether the following statement is True or False: Evolution is the gradual change occurring in living organisms over a long duration.

Answer: True

(ii) Write the name of any one sexual disease.

Answer: Syphilis (or Gonorrhea / AIDS)

(iii) Select odd man out: Gutkha, Yoga, Alcoholic drinks, Cigarette.

Answer: Yoga (Others are addictive and harmful substances).

(iv) Fill in the box with proper word: Kinetic Energy in wind -> [ ______ ]

Answer: Kinetic Energy in Turbine (or eventually Electrical Energy).

(v) Match the correct pair:

Column A	Column B
Xylitol	(b) To impart sweetness

Question 2

(A) Give scientific reasons (any two):

(i) Some of the organs in human body are most valuable.

Reason: Certain organs like the kidneys, heart, liver, and eyes are vital for survival or quality of life. If these organs fail, a person's life is at risk. However, these organs can be donated (after death or in some cases like kidneys/liver lobe while alive) to save the lives of patients in need. Due to their life-saving potential and scarcity, they are considered most valuable.

(ii) Hydroelectric energy, solar energy and wind energy are called renewable energies.

Reason: These energy sources are obtained from inexhaustible natural resources (water, sun, wind) that are continuously replenished by nature. Unlike fossil fuels, they do not run out after use and are generally eco-friendly. Hence, they are called renewable energies.

(iii) Fibres are one of the important nutrients.

Reason: Although human bodies cannot digest fibres, they are crucial for digestion. They help in the digestion of other substances and facilitate the excretion of undigested food (egestion), preventing constipation. Therefore, they are considered important nutrients.

(B) Answer the following questions (any three):

(i) Observe the given animals (Fig A: Duck-billed Platypus, Fig B: Lungfish) and answer the questions:

(a) Identify the animals:
Fig A: Duck-billed Platypus
Fig B: Lungfish

(b) State the type of evidence of evolution:
Connecting Links.

(ii) Complete the chart: Asexual reproduction in multicellular organisms.

1. Fragmentation
2. Regeneration
3. Budding
4. Vegetative Propagation
5. Spore Formation

(iii) Complete the table:

Sr. No.	Microbe used	Name of beverage
1.	Lactobacillus brevis	Coffee
2.	Candida, Hansenula, Pichia, Saccharomyces	Cocoa
3.	Saccharomyces cerevisiae	Wine
4.	Saccharomyces cerevisiae	Cider

(iv) Give two examples of each:

(a) Physical problems arising due to excessive use of mobile phones:
1. Headache / Insomnia
2. Vision problems / Joint pain

(b) Activities under the jurisdiction of cyber crime laws:
1. Hacking of information / Bank frauds
2. Identity theft / Cyber stalking

(v) Write any two objectives of disaster management.

1. To save human lives and property from disasters.
2. To supply essential commodities (food, water, medicine) to affected people.
3. To rehabilitate the affected people and restore normalcy in the area.

Question 3

Answer the following questions (any five):

(i) Distinguish between Sexual reproduction and Asexual reproduction.

Sexual Reproduction	Asexual Reproduction
Two parents (male and female) are involved.	Only one parent is involved.
Germ cells (Gametes) are formed.	Gametes are not formed.
Offspring show genetic variation.	Offspring are genetically identical (clones).
It is a slower process.	It is a faster process.

(ii) Complete the chart (Respiration / Glycolysis):

(a) Fatty acids
(b) Amino acids
(c) Pyruvic acid
(d) Acetyl Co-A
(e) Krebs Cycle
(f) CO₂ + H₂O + Energy

(iii) Answer the following questions (Vestigial Organs):

(a) Define vestigial organs: Degenerated or underdeveloped useless organs of organisms are called vestigial organs.
(b) Two vestigial organs in human body: Appendix, Tail bone (Coccyx), Wisdom teeth, Ear muscles.
(c) Organs non-functional in humans but functional in others: Appendix (functional in ruminants), Ear muscles (functional in monkeys).

(iv) Complete the following flow chart (Thermal Energy):

Generation of electrical energy using thermal energy:
Fuel Coal → [Boiler for conversion of water to steam] → [Steam Turbine] → Generator → Electrical energy

Energy transformation:
Chemical energy in coal → [Thermal energy] → [Kinetic energy in steam] → [Kinetic energy in turbine] → Electrical energy

(v) Complete the paragraph regarding Cheese Production:

Cheese is produced on large scale from the abundantly available milk all over the world. First chemical and microbiological tests of milk are performed. Some colours and microbes like Lactobacillus lactis, Lactobacillus cremoris and Streptococcus thermophilus are mixed with milk. It imparts sourness to the milk. After this, to impart the dense texture, whey needs to be removed. An enzyme rennet obtained from alimentary canal of cattle was being traditionally used earlier. However an enzyme protease obtained from fungi is used at present to produce cheese.

(vi) Write a short note on the importance of medicinal plants.

India has a great tradition of Ayurveda that cures diseases with the help of natural resources. Medicinal plants are the main source of these cures. For example, Adulsa is used for cough and cold, Tulsi is an immunity booster, and Ashwagandha is used for vitality. Conservation of these plants is crucial as they provide side-effect-free remedies.

(vii) Explain the importance of good communication with others.

Good communication helps to express one's feelings, problems, and thoughts effectively. It helps in relieving stress and mental pressure. Communicating with parents, teachers, and friends helps in finding solutions to problems, thereby preventing depression and maintaining good social health.

(viii) Identify the type of disaster and write its effect:

Event	Type of Disaster	Effect
(a) Terrorism	Man-made (Intentional)	Loss of life, Property damage, Fear/Panic
(b) Forest Fire	Natural or Man-made	Loss of biodiversity, Air pollution
(c) Theft	Man-made (Intentional)	Financial loss, Mental stress

Question 4

Answer the following questions (any one):

(i) Complete the following flow chart explaining my role in environmental conservation:

My Role in Environmental Conservation:

• Conservation: Conserving the available resources.
• Control: Preventing the harm; stopping the harmful activities.
• Production: Revival of harmed factors of environment; attempting innovation.
• Awareness: Education, guidance, awareness, imitation, organization, participation.
• Prevention: Preventing possible harms; designing new plans; factors harmful to environment.
• Preservation: Preserving whatever has been left; preserving biodiversity.

(ii) Observe the picture (Fig A: Fish, Fig B: Pigeon) and answer the questions:

(a) Identify the class of animals shown in above picture.
Fig A (Fish) belongs to Class Pisces.
Fig B (Pigeon) belongs to Class Aves.

(b) Which similarities are shown in above animals from the adaptation point of view?
Both animals have a spindle-shaped (streamlined) body. This adaptation minimizes the resistance of the surrounding medium (water for fish, air for birds) during movement.

(c) Why these animals are included in different classes inspite of their similarities?
Despite the streamlined shape, they have major differences:

• Respiration: Fish use gills, Birds use lungs.
• Habitat: Fish are aquatic, Birds are aerial/terrestrial.
• Skin: Fish have scales, Birds have feathers.
• Thermoregulation: Fish are cold-blooded (Poikilotherms), Birds are warm-blooded (Homeotherms).

10th Science and Technology Part 2 March 2025 Board Exam Question Paper with Solutions

Q. 1. (A) Choose the correct option and write the correct alternative.

(i) A molecule of glucose is completely oxidised in aerobic respiration and molecules of \(H_{2}O\) and __________ are produced along with energy.

• (A) \(CO_{2}\)
• (B) \(O_{2}\)
• (C) NaOH
• (D) \(HNO_{3}\)

Answer: (A) \(CO_{2}\)

(ii) Vinegar contains __________ acid.

• (A) acetic
• (B) lactic
• (C) tartaric
• (D) hydrochloric

Answer: (A) acetic

(iii) Any nucleotide of the gene suddenly changes its position that causes a minor change which is nothing but the __________.

• (A) changes
• (B) mutation
• (C) disability
• (D) translocation

Answer: (B) mutation

(iv) In humans, sperm production occurs in the __________ organ.

• (A) vas deferens
• (B) ejaculatory duct
• (C) testes
• (D) urinogenital duct

Answer: (C) testes

(v) Solar photovoltaic cell converts the solar radiation energy directly into __________ energy.

• (A) Chemical
• (B) Solar
• (C) Mechanical
• (D) Electrical

Answer: (D) Electrical

Q. 1. (B) Answer the following questions.

(i) Find the odd one out: Fragmentation, Regeneration, Budding, Fertilization.

Answer: Fertilization
Reason: Fertilization involves sexual reproduction, while Fragmentation, Regeneration, and Budding are types of asexual reproduction.

(ii) Write the correct co-relation: Diabetes : Insulin :: Cancer : _______

Answer: Interferon (or Chemotherapy)

(iii) State whether true or false: Study of fossils is an important aspect of the study of evolution.

Answer: True

(iv) Give any two commercial uses of Biotechnology.

Answer:

1. Production of vaccines and antibiotics.
2. Production of genetically modified crops (e.g., Bt Cotton).
3. Production of yogurt and other dairy products.

(v) Being a fish, I perform respiration with the help of lungs. Who am I?

Answer: Lungfish

Q. 2. (A) Give scientific reasons (any two).

(i) Sometimes, higher plants and animals too perform anaerobic respiration.

Reason:

• Aerobic respiration requires oxygen. However, when the oxygen level in the surroundings is depleted, higher plants and animals switch to anaerobic respiration to survive.
• For example, during heavy exercise, human muscle cells perform anaerobic respiration due to a lack of oxygen, producing lactic acid.
• Similarly, plants may perform anaerobic respiration if the soil is waterlogged and roots cannot access oxygen.

(ii) It is not right to consider the mother responsible for giving birth to a girl child.

Reason:

• Human females have two X chromosomes (XX), so all egg cells produced carry an X chromosome.
• Human males have one X and one Y chromosome (XY). Therefore, 50% of sperms carry the X chromosome and 50% carry the Y chromosome.
• The sex of the child depends entirely on which sperm fertilizes the egg. If an X-bearing sperm fertilizes the egg, the child is a girl (XX). If a Y-bearing sperm fertilizes the egg, the child is a boy (XY). Thus, the father determines the sex of the child.

(iii) The energy generated from nuclear fuels is not environment friendly.

Reason:

• Nuclear power plants produce radioactive waste which is hazardous and difficult to dispose of safely.
• There is a risk of harmful radiation leakage which can cause severe health problems, including cancer and genetic mutations.
• Accidents in nuclear plants can lead to catastrophic environmental disasters.

Q. 2. (B) Answer the following questions (any three).

(i) Complete the following food chain: Grass -> ______ -> Frog -> ______ -> Eagle -> ______

Answer:
Grass -> Grasshopper -> Frog -> Snake -> Eagle -> Fungi

(ii) Distinguish between Class Pisces and Class Reptilia (Reptiles).

Class Pisces	Class Reptilia
They are aquatic animals (live in water).	They are mostly terrestrial (live on land) and creep/crawl.
Respiration occurs through gills.	Respiration occurs through lungs.
Body is covered with scales.	Skin is dry and rough with scales/scutes.

(iii) Observe the picture (Train in flood water) and write any two effects of this disaster.

Note: The image depicts a flood situation. Effects of Floods:

1. Disruption of life: Transportation systems (like trains) collapse, and daily life comes to a standstill.
2. Economic Loss: Huge loss of life and property; damage to crops and infrastructure.
3. Health Hazards: Spread of water-borne diseases and contamination of drinking water sources.

(iv) Write any four methods to reduce stress.

Answer:

1. Regular Exercise and Yoga.
2. Meditation.
3. Pursuing hobbies like reading, painting, or singing.
4. Communication with parents and friends (Socializing).

(v) Complete the following conceptual picture: Sewage after processing.

Answer: The by-products obtained after sewage processing are:

Potable Water / Clean Water

Biogas (Fuel)

Sludge (Fertilizer/Manure)

Electricity (from Biogas)

Q. 3. Answer the following questions (any five).

(i) Define heredity. Explain the mechanism of hereditary changes.

Definition: Heredity is the transfer of biological characters from one generation to another via genes.

Mechanism of Hereditary Changes:

• Mutation: Sometimes, any nucleotide of the gene changes its position, causing a minor change in the genetic code. This is called mutation.
• Recombination: During meiosis (gamete formation), crossing over occurs between homologous chromosomes, leading to genetic variation.
• These changes can lead to evolution and the development of new species over long periods.

(ii) Write any four stages of mitosis and explain any two of them.

The four stages of Mitosis (Karyokinesis) are: 1. Prophase 2. Metaphase 3. Anaphase 4. Telophase.

Explanation:

• Prophase: Chromosomes condense and become visible. The nuclear membrane and nucleolus start to disappear. Centrioles move to opposite poles.
• Metaphase: Chromosomes align parallel to the equatorial plane (center) of the cell. Spindle fibers attach to the centromere of each chromosome.

(iii) Explain with examples types of asexual reproduction in unicellular organism.

Types of Asexual Reproduction in Unicellular Organisms:

1. Binary Fission: The parent cell divides into two equal daughter cells. Example: Amoeba, Paramecium.
2. Multiple Fission: Under unfavorable conditions, the parent creates a cyst and divides many times inside to produce multiple daughter cells. Example: Amoeba.
3. Budding: A small outgrowth (bud) forms on the parent cell, grows, and eventually detaches to form a new organism. Example: Yeast.

(iv) Which fuel is used in thermal power plant? Write any two problems associated with this type of power generation.

Fuel Used: Coal.

Problems:

1. Air Pollution: Burning coal releases harmful gases like Carbon Dioxide (\(CO_2\)), Sulphur Dioxide (\(SO_2\)), and Nitrogen Oxide (\(NO_x\)) which cause respiratory issues and acid rain.
2. Soot Particles: Minute soot particles released into the air can cause serious health problems related to the respiratory system.

(v) Write three characteristics of phylum-Mollusca.

Characteristics of Phylum Mollusca:

1. Body Structure: They have a soft, slimy body. They are the second-largest phylum in the animal kingdom.
2. Shell: Most molluscs have a hard, calcareous shell which provides protection. It may be external or internal.
3. Locomotion: They move with the help of a muscular foot.
4. Habitat: They are aquatic (marine or fresh water) or terrestrial. (Example: Snail, Octopus, Bivalve).

(vi) What are the constituents of acid rain? What are its two effects on earth's surface?

Constituents: Sulphuric acid (\(H_2SO_4\)) and Nitric acid (\(HNO_3\)). These are formed when oxides of sulphur and nitrogen react with rain water.

Effects:

1. Soil and Water Bodies: Acidity of soil and water bodies increases, harming aquatic life and plants.
2. Damage to Structures: Acid rain causes corrosion of buildings, bridges, historical monuments (like the Taj Mahal), and metal structures.

(vii) Solve the following crossword (Based on Social Health).

Clues & Answers:

• 1. (Across) Continuous consumption of alcoholic and tobacco materials: ADDICTION
• 2. (Down) This app may cause cyber crimes (6 letters, crosses 'C'): SOCIAL (Referring to Social Media) or MOBILE.
• 3. (Down) A remedy to resolve stress (Crosses 'N'): FRIEND (Spending time with friends reduces stress) or SINGING.
• 4. (Down) Requirement for stress free life (Crosses 'D'): GARDEN (Hobbies) or INDOOR (Games).

*Note: In the context of the syllabus, answers typically revolve around "Addiction", "Social Media/Facebook", "Hobbies/Singing".

(viii) Write down the reasons, effects and remedial measures taken for any one disaster seen or heard by you.

Example Disaster: Earthquake

• Reasons: Movement of tectonic plates inside the earth's crust, volcanic eruptions, or mining activities.
• Effects: Collapse of buildings, loss of life, landslides, disruption of electricity and communication lines.
• Remedial Measures:
  • Take cover under a strong table or door frame.
  • Move to open ground away from buildings.
  • Help victims and call emergency services.

Q. 4. Answer the following questions (any one).

(i) What is biodiversity? Write any four steps to conserve biodiversity.

Biodiversity: It is the richness of living organisms in nature due to the presence of varieties of organisms, ecosystems, and genetic variations within a species.

Steps to Conserve Biodiversity:

1. Protecting rare species of organisms.
2. Establishing National Parks and Sanctuaries.
3. Declaring some regions as "Bio-reserves".
4. Projects for conservation of special species.
5. Observing the rules regarding the ban on poaching/hunting.

(ii) What is stem cell? Write any four uses of stem cell.

Stem Cell: Stem cells are special types of undifferentiated cells in multicellular organisms that have the ability to differentiate into various types of specialized cells (like muscle cells, blood cells, etc.).

Uses of Stem Cells:

1. Regenerative Therapy: Used in Cell Therapy to replace dead cells in diseases like Diabetes and Alzheimer's.
2. Organ Transplantation: Used to produce organs like the liver or kidney for patients in need.
3. Blood Cell Production: To treat blood diseases like Thalassemia and Leukemia.
4. Research: Used to study the development of diseases and test new drugs.

Water Conservation Project: Importance, Analysis, and Methods. For School and College Students.

Water Conservation

A Comprehensive Project Report

1. Selection of Project Topic (Introduction)

Nature has gifted us some precious and valuable resources and water is one of them and is our basic need.

Tomorrow morning you wake up and find that there's no water running from the washroom tap. So you go to the kitchen and find there's no water in the kitchen tap too. This go for a few hours and you realize that water from the world has vanished mysteriously. What would happen? And there's no one to blame but ourselves. Hard to imagine, isn't it? So let's not waste any more time and start conserving water this minute itself.

Now the world is heading towards water crises due to the excessive and uneconomical use of water by the large human population. Human beings waste tons of water while brushing teeth, bathing, washing clothes, vehicles and utensils, etc. Overuse of water has led to a decrease in supply of water available for human use.

Conserving water means using our water supply wisely and be responsible. As every individual depends upon water for livelihood, we must learn how to keep our limited supply of water.

The uses of water are endless —

Bottom line:

We need water for activities and habits we use regularly. If we want to continue to keep our bodies healthy, clean and everything else – we must conserve water.

Water grows food.

It protects our ecosystem and wildlife.

Less water usage means more savings.

Water supply is already limited.

Conserving water also saves energy.

— EVERY 🌧️ DROP COUNTS —

2. Importance of the Topic

Importance of Water:

Water is an essential element and plays an important role in the human body. We can survive upto several weeks without food, but only a few days without water. Every system in the body from cells and tissues, to vital organs requires water to function.

Need of Water Conservation:

Although \(71\%\) of earth is covered with water, acute shortage of water is reported all over the world. India receives nearly \(4\%\) of global precipitation, still it suffers from water scarcity.

Increasing industrialization is exerting pressure on existing water resources. Rapid urbanization has also increased the pressure on groundwater sources like tube wells.

Although water is a renewable source, the misuse and wastage of water has resulted in depletion of water resource, conserving water has become a major environmental issue.

3. Objectives of Project Work

The objectives of project work are as follows:

1] To increase the awareness of scarcity of water caused due to blind wastage of water.

2] To change citizen attitudes and behaviour to improve water use efficiency.

3] Improving water management practices that reduce the use or enhance the beneficial use of water.

4] To ensure that, future generation should not face scarcity of water.

5] To imbibe the idea of rainwater harvesting in the minds of common citizens.

6] Presenting statistical data about clean water level decline and to put forth a step ahead for conserving water, "water is life" as the saying 'says'.

4. Project Work Methodology

ABSTRACT:

India has \(16\%\) of the world's population and only \(4\%\) of the world's water resource, which are depleting rapidly.

The demand for water is expected to grow from \(40 \text{ billion}\) cubic meters (\(\text{bcm}\)) currently to around \(220 \text{ bcm}\) in 2025. Water is one of the most important inputs essential for crops. Both its shortage and excess affects the growth and development of the plants, yields and quality of produce. There are numerous methods to reduce such losses and to improve soil moisture.

While experts appreciate the change in mindsets to provide drinking water supply, the real challenge, they say, is to bring a revolution in water use in farming.

Hearteningly, this is being driven by a rare public private partnership between government and farmers, throwing up innovative cost effective solutions. For instance, in Dewas district in Madhya Pradesh, water had become scare for farmers, who were reduced to growing only one crop.

Deterioration of Water Quality:

Water quality refers to purity of water or water without unwanted substances.

The major sources for water pollution are:

1. Domestic wastes (Sewage): This primarily includes excreta of humans and animals along with papers, food waste, detergents, etc. Various discarded materials ultimately gets accumulated in nearby water bodies like lakes, ponds and rivers.

2. Industrial wastes: Huge amount of water is needed for manufacturing process in steel and paper industries. Hence such industries are set up on the banks of rivers. Many other industries like textile, rubber, leather, medicine, etc. are responsible for water pollution.

This polluted water after certain scientific methods if reused then less water will be consume which leads to water conservation.

Rainwater Harvesting

Fig: Simple mechanism for Rainwater Harvesting

Rainwater harvesting is the simple process our technology used to conserve rainwater by collecting, storing, conveying and purifying of rainwater that runs off from rooftops generally, for later use.

It is simple process which can be afford by most of the population, which can benefits themselves as well as to the whole society.

Paani Foundation:

Paani foundation was set up in 2016 by the core team of 'Satyamev Jayate' show to learn.

It is a non-profit, non-governmental organization which is active in the area of drought preventing and watershed management in the state of Maharashtra. The Founders are 'Aamir Khan' & 'Kiran Rao'. The primary aim of Paani Foundation is to spread knowledge of watershed management and groundwater replenishment.

Many such organizations are now working on water conservations. Initiatives like Jal Shakti Abhiyan which improves water conservation can improve the stress conditions.

Water metering:

Nowadays, efficient way of cutting down water wastage is to install water meters and measure the amount of water that is being used in residential and commercial buildings. The volume of water used is calculated and charged according to the price of water.

5. Observations

The per capita water availability is a widely accepted parameter for gauging the water security for a country. By this information, India is already in water stress condition, as per estimation by 2050 with the population of \(1.6 \text{ billion}\), the water availability can be further reduce.

Water Availability

Data Breakdown:

Total Precipitation: \(4000 \text{ BCM}\)

Total water availability: \(1869 \text{ BCM}\)

Total utilizable water resources: \(1123 \text{ BCM}\)

Breakdown of Resources:
Surface water: \(690 \text{ BCM}\)
Ground water: \(433 \text{ BCM}\)

Current Utilization:
Surface Water (SW): \(450 \text{ BCM}\) (\(65.21\%\))
Ground Water (GW): \(243 \text{ BCM}\) (\(56\%\))

Presently meets the demand, but is inadequate for future demand.

Global Water Scenario

Our observation has shown that, high income households tends to consume \(250 \text{ litres}\) (per head and above) and sometimes as high as \(600 \text{ litres}\). Many homes on the other hand make to do with as little as \(40 \text{ litres}\) per person/day.

While some water efficient devices such as low flush toilets and low demand showers are available in the market, there is no conditionality being imposed that all water delivering devices should meet certain efficiency norms. It is essential in a water-scare country that all taps, showers, washing machine, flushes should be water efficient.

How much water do we consume on a daily basis?

Spain's national statistics institute reported that average water consumption in the world was \(137 \text{ lit/day}\) in 2012, that number exceeds the minimum required per person. Optimal access allows for the consumption of \(100 \text{ litres}\) per person per day. In India, the average water consumption is taken to be \(135 \text{ lit/per day/person}\).

Bathing: \(55 \text{ litres}\)

Toilet flushing: \(30 \text{ litres}\)

Washing of clothes: \(20 \text{ litres}\)

Washing utensils: \(10 \text{ litres}\)

Washing house: \(10 \text{ litres}\)

Cooking: \(5 \text{ litres}\)

Drinking: \(5 \text{ litres}\)

6. Analysis of Data

Flow rate regulation system:

The following system concentrates on manipulating household products such as taps, showers, toilets to reduce the amount of water consumed daily.

Taps: Water efficient taps are fixed with tap aerators which amplify the supposed volume and flow of water. A standard tap releases between 15 and 18 liters of water per minute while water efficient tap supplies 6 liters per minute.

Product	Normal Product	Water efficient Product
1) Tap	\(15-18 \text{ liters/minute}\)	\(6 \text{ liters/minute}\)
2) Shower heads	\(15-25 \text{ lit/min}\)	\(6-8 \text{ lit/min}\)
3) Toilets	\(10-13 \text{ lit/flush}\)	\(3-6 \text{ lit/flush}\)

Analysis of rainwater harvesting:

In this system, run off flow is a function of roof size. The larger the roof the higher the run-off flow the converse is a case for smaller roofs. The rainwater obtained from a roof in a year is estimated as the product of roof's plan area. In the tropics \(75\%\) of this water runs off the roof while \(25\%\) is lost due to evaporation and splashing occurrences.

Primary data analyzed for this system was that of rainfall. Rainfall is an important factor here. Consequently higher amount of rainfall leads to higher amount of water available for harvest.

Therefore, months which experience dry periods would result to no water in the system unless previously stored in times of heavy rainfall. However, the analysis shows that on an average between peaks of rainfall, there is average water saving of \(17\%\) anually.

Greywater Harvesting:

Greywater harvesting refers to untreated wastewater which is not contaminated by toilet waste. It comprises of water discharged from bathtubs, showers, hand basins, laundry tubs, floor wastes and washing machines. Water released from the dishwasher, kitchen sink or garbage disposal is not included.

Greywater can be re-used for non-potable use such as landscaping, watering outdoor gardens, flushing toilets, etc. It is also an alternative towards water conservation.

Analysis:

In the greywater system, an estimated \(37\%\) of greywater is produced by a household. \(25\%\) of water is required for toilet flushes or irrigation purposes, while the excess is discharged as overflow to the different stream line. This system line can recycle the water further or end in the sewer system.

Through Analysis, following measures are found to be effective:

1] Renewing traditional water harvesting system.

2] Renovating old lakes and ponds.

3] Building check dams.

4] Keeping control of water resources to the community.

5] Rainwater harvesting in urban area.

6] Recharging groundwater from percolation pits.

7] Adopting Integrated Watershed Management (IWM).

8] Reducing demand through increased efficiency of water use.

7. Results and Conclusions

Water problems will not go away by themselves. On the contrary, they will worsen unless we, as a global community, respond and use water responsibly. So, before it is too late, let us all, as individuals, families, communities, companies and institutions, pledge towards using water wisely. Intelligence is not in lavishness, but in conservation, so that our future generations can continue to enjoy the blissful feeling and touch of water.

Following are some measures to conserve water at our primary stage:

1) Close taps after use, properly; do not leave the tap running if not in use.

2) Try to implement Rainwater harvesting.

3) Re-use water as much as possible.

4) Improve water management, use modern irrigation methods which consume less water.

5) Public education and awareness.

Wonders of Nature | Term 3 Unit 5 | Class 2 EVS Environmental Science Questions and Answers

வியத்தகு இயற்கை

பருவம்-3 அலகு 5 | 2வது EVS சுற்றுச்சூழல் அறிவியல்

மதிப்பீடு

1. பாகங்களைக் குறிக்க. (வெட்டுப்பட்ட பள்ளம் போன்ற அமைப்பு, உணர் நீட்சி)

2. கோடிட்ட இடங்களை நிரப்பி எந்தத் தாவரம் அல்லது விலங்கு எனக் கண்டுபிடிக்க.

நான் மலையில் மலர்வேன். (மலையில் / பாலைவனத்தில்)

நான் ஊதா நீல நிறத்தில் இருப்பேன். ( பழுப்பு / ஊதா நீல )

என்னால் தான் நீலகிரி ( நீலகிரி / ஏலகிரி ) என்ற பெயர் உருவானது.

நான் யார்? குறிஞ்சி

எனக்கு இரண்டு இணை உணர்நீட்சிகள் உள்ளன. ( இரண்டு / நான்கு )

என்னுடைய கண்கள் உணர்நீட்சியில் ( உணர்நீட்சியில் / வாலில் ) காணப்படும்.

நான் என் உடலை என்னுடைய கூட்டினுள் இழுத்துக்கொள்வேன்.

நான் யார்? நத்தை

3. பொருத்துக.

பொருத்த வேண்டியவை:

சிலந்தி

வேர்க்கடலை

நத்தை

பல்லி

ஓடு

மீண்டும் வளரும் வால்

8 கால்கள்

தரைக்கு அடியில் வளரும்

சரியான விடை:

(i) சிலந்தி - 8 கால்கள்

(ii) வேர்க்கடலை - தரைக்கு அடியில் வளரும்

(iii) நத்தை - ஓடு

(iv) பல்லி - மீண்டும் வளரும் வால்

பாடப்புத்தகத்தில் உள்ளபடி:

4. சரியான சொற்களைக் கொண்டு கோடிட்ட இடங்களை நிரப்புக.

1. வேர்க்கடலை தாவரத்தில் கொட்டைகள் மண்ணிற்கு அடியில் காணப்படும். (அடியில் / மேல்)

2. எருக்குத் தாவரத்தின் மலர்கள் கிரீடம் வடிவில் காணப்படும். ( கிரீடம் / கோள )

3. பூச்சிகள் மலரிலிருந்து தேனை உறிஞ்சுகின்றன. ( தேனை / பாலை )

4. சிலந்தி ஒரு பூச்சி அல்ல. ( தேனீ / சிலந்தி )

5. பல்லியின் வால் துண்டிக்கப்பட்டாலும் மீண்டும் வளரும். ( பல்லியின் / நாயின்)

5. மலர்கள் மற்றும் விலங்கின் பெயரைத் தேர்ந்தெடுத்து எழுதுக.

(மல்லிகை / எருக்கு) (சிலந்தி / நத்தை) (வெட்சிப் பூ / சங்கு பூ)

தன் மதிப்பீடு

* என்னைச் சுற்றியுள்ள வியத்தகு தாவர மற்றும் விலங்குலக இயற்கையை உற்றுநோக்கி வியந்தேன்.

2nd EVS Wonders of Nature | Term 3 Unit 5 | Samacheer Kalvi

பருவம்-3 அலகு 5: வியத்தகு இயற்கை

2வது EVS சுற்றுச்சூழல் அறிவியல்

நீங்கள் கற்க இருப்பவை

* வியத்தகு இயற்கை-தாவரங்கள் மற்றும் விலங்குகள்

* மலர்களின் நிறமும் மணமும்

வியத்தகு இயற்கை – தாவரங்கள்

இயற்கை வியப்பான பல அம்சங்கள் நிறைந்து காணப்படுகிறது. அவற்றுள் சிலவற்றைக் குறித்து தெரிந்து கொள்வோமா!

அல்லி

அல்லி இலைகளின் மேல் நீர் தேங்குவதில்லை / ஒட்டுவதில்லை, ஏனெனில் அல்லி இலைகளின் மேற்பரப்பில் மெழுகுப்படலம் காணப்படுகிறது. அதுமட்டுமின்றி இலைக்காம்பு பகுதியில் வெட்டுப்பட்ட பள்ளம் போன்ற அமைப்பும் காணப்படும். இந்த அமைப்பும் மெழுகுப்படலமுமே நீரானது இலையின் மேல் தேங்காமல் இருப்பதன் காரணம் ஆகும்.

மண்ணிற்கு / தரைக்கு அடியில் காணப்படும் கொட்டைகள்

பொதுவாக, கொட்டைகள் / காய்கள் தாவரத்தின் தண்டுப்பகுதியில் காணப்படும். ஆனால், வேர்க்கடலைத் தாவரத்தில் கொட்டைகள் மண்ணிற்கு அடியில் காணப்படும்.

கொட்டைகளை விதைகள் என்றும் கூறலாம்.

குறிஞ்சி

குறிஞ்சி அல்லது நீலக்குறிஞ்சி ஒரு புதர் வகைச்செடி. இது தமிழ்நாட்டில் ஊட்டியில் உள்ள நீலகிரி மலையில் காணப்படுகிறது.

நீலக்குறிஞ்சி மலர்கள் 12 ஆண்டுகளுக்கு ஒரு முறை மட்டுமே மலரும்.

இம்மலர்கள் ஊதா நீல வண்ணத்தில் காணப்படும். எனவே, இந்த மலைப்பகுதி நீலகிரி எனப் பெயர் பெற்றது.

தொட்டாற் சிணுங்கி

இந்தத் தாவரத்தை நீங்கள் பார்த்திருக்கிறீர்களா? இது பெரும்பாலான இடங்களில் காணப்படும் சிறு செடி வகை. இத்தாவரத்தின் இலைகளை நாம் தொட்டால் அவை உடனடியாக மூடிக்கொள்ளும். எனவேதான் இதனைத் தொட்டாற் சிணுங்கி தாவரம் என அழைக்கிறோம். ஆனாலும் மூடிய இலைகள் சில நிமிடங்களில் விரிந்து விடும்.

எருக்கு

எருக்கு புதர்ச்செடி வகையைச் சார்ந்தது. இத்தாவரம் மெழுகுப்பூச்சு கொண்ட கொத்தான மலர்களைக் கொண்டிருக்கும். இதன் மலர்கள் வெள்ளை அல்லது ஊதா நிறத்தில் கிரீடம் போன்று காணப்படும். எனவே, இது கிரீட மலர் எனப்படுகிறது.

எருக்கு இலையை வரைந்து வண்ணம் தீட்டுக.

மலர்களின் நிறமும் மணமும்

மலர்கள் அழகான வண்ணமும் நறுமணமும் கொண்டவை. இவை பூச்சிகளைத் தம்பால் ஈர்க்கின்றன. பூச்சிகள் மலர்களின் நண்பர்கள். மலர்களில் தேன் சுரப்பிகள் காணப்படுகின்றன. இதிலுள்ள தேனை உறிஞ்சவே பூச்சிகளும் பறவைகளும் மலர்களை நாடி வருகின்றன.

இரவில் மலரும் பெரும்பான்மையான மலர்கள் வெள்ளை நிறத்திலும், அதிக மணத்துடனும் / வாசனையுடனும் காணப்படும்.

பகலில் மலரும் மலர்கள் கண்ணைக் கவரும் பல வண்ணங்களிலும் குறைவான நறுமணத்துடனும் காணப்படும்.

புள்ளிகளை இணைத்து படத்திற்கு வண்ணம் தீட்டுக.

வியத்தகு இயற்கை – விலங்குகள்

பச்சோந்தி

படத்தில் காணும் விலங்கைப் பார்த்திருக்கிறீர்களா? இதுதான் பச்சோந்தி. இது பல்லி இனத்தைச் சார்ந்தது. பச்சோந்தி தான் இருக்கும் சுற்றுப்புறத்திற்கு ஏற்றாற்போல் தன் தோலின் நிறத்தை மாற்றிக்கொள்ளும் தன்மை உடையது. இந்த நிறம் மாறும் தன்மையால் இது எதிரிகளிடமிருந்து தன்னைத் தற்காத்துக் கொள்கிறது.

பல்லி

பல்லி மேற்கூரையில் தலைகீழாகத் தொங்கிக் கொண்டிருப்பதைப் பார்த்திருக்கிறீர்களா? பல்லிகளின் கால் விரல்களில் காணப்படும் விரல் பட்டைகளின் உதவியால் அவை சுவரில் / கூரையில் இருந்து கீழே விழாமல் ஒட்டிக் கொண்டுள்ளன. பல்லியின் வால் துண்டிக்கப்பட்டால் மீண்டும் ஒன்று அல்லது இரண்டு (ஓரிரு) மாதத்திற்குள் வளரக்கூடிய சிறப்புத்தன்மை உடையது.

சிலந்தி

பூச்சிகளுக்கு ஆறு கால்கள் மட்டும்தான் உண்டு என்பது உங்களுக்கு நினைவிருக்கிறதா?

சிலந்தி பூச்சி வகையைச் சார்ந்தது அன்று. ஏனெனில் இதற்கு எட்டு கால்கள் உள்ளன. சிலந்தி நூல் போன்ற இழையை (சிலந்தி பட்டு) உருவாக்கி, சிலந்தி வலையைப் பின்னுகிறது. இந்த இழைகள் மிகவும் வலிமையானவை. மேலும் ஒட்டும் தன்மை உடையவை. இந்த வலையின் உதவியுடன் பூச்சிகளைப் பிடித்து இரையாக்கிக் கொள்கிறது.

நாய்

நாய் நம்மை விட அதிக மோப்ப சக்தி / நுகரும் திறன் கொண்டது. இவை வெகு தொலைவில் கேட்கும் மிக நுண்ணிய ஒலிகளையும் உணரும் தன்மை கொண்டவை. காவல் துறையில் திருடர்களைக் கண்டுபிடிக்க நாய்கள் பயன்படுத்தப்படுகின்றன. இவ்வகை நாய்கள் "மோப்ப நாய்கள்" எனப்படுகின்றன. இவை நிலநடுக்கம் போன்ற இயற்கை சீற்றங்களில் சிக்கிய மனிதர்களைக் கண்டறியவும் பயன்படுத்தப்படுகின்றன.

எலி

எலி வீடு மற்றும் வயல்களில் வாழும் சிறிய விலங்கு. இது ஒட்டகத்தை விட அதிக நாள் நீர் இல்லாமல் வாழக் கூடியது. கடினத்தன்மை உடைய மரக்கட்டைகளையும் தன்னுடைய பற்களால் கடித்துவிடும். எலியின் சில பற்கள் தொடர்ந்து வளர்ந்துகொண்டே இருக்கும். அவை பெரிதாக வளர்ந்து விடாமல் இருக்க எலிகள் எப்பொழுதும் பற்களை கொறித்துக் கொண்டேயிருக்கும்.

நத்தை

நத்தையின் தலைப்பகுதியில் இரண்டு இணை உணர் நீட்சிகள் காணப்படும். அவற்றுள் ஒன்று நீண்டதாகவும், மற்றொன்று குட்டையாகவும் இருக்கும். நீண்ட உணர்நீட்சியில் கண்கள் காணப்படும். நாம் நத்தையைத் தொட்டால் ஆமையைப்போல தன் உடல் பகுதியை ஓட்டிற்குள் இழுத்துக்கொள்ளும்.

பல்வேறு வகையான விலங்குகளைக் கண்டுபிடித்து எண்ணி எழுதுக.

2nd EVS Environmental Science: Day and Night | Term 3 Unit 4 | Questions and Answers

பகலும் இரவும் | பருவம்-3 அலகு 4 | 2வது EVS சுற்றுச்சூழல் அறிவியல்

மதிப்பீடு

1. படங்களின் பெயரை எழுதுக. (நிலா, பூமி, நட்சத்திரங்கள், சூரியன்)

2. இரவில் உலவும் விலங்குகளின் பெயரை எழுதுக.

(பசு, ஓநாய், மான், கரப்பான்பூச்சி, குரங்கு, மின்மினிப் பூச்சி, முயல், அணில், எலி)

3. பின்வரும் கூற்று சரி எனில் 'ச' எனவும் தவறு எனில் 'த' எனவும் குறிப்பிடுக.

1. சூரியன் நமக்கு ஒளியையும் வெப்பத்தையும் தருகிறது. (ச)

2. நிலவின் வடிவம் ஒவ்வொரு இரவும் மாறுபடுகிறது. (த)

3. நட்சத்திரக் குழுக்கள் பல்வேறு அமைப்புகளில் காணப்படுகின்றன. (ச)

4. மல்லிகை பகல் நேரத்தில் மலரும். (த)

5. நீங்கள் கிழக்கு நோக்கி நிற்கும் போது உங்களுக்கு வலப்பக்கம் இருப்பது மேற்கு. (த)

4. பின்வரும் படத்தை உற்றுநோக்கி கோடிட்ட இடங்களை நிரப்புக.

(மரம், பூக்கள், குளம், நாய்)

அ. தோட்டத்தின் தெற்குத் திசையில் காணப்படுவது குளம்.

ஆ. தோட்டத்தின் வடக்குத் திசையில் காணப்படுவது மரம்.

இ. தோட்டத்தின் கிழக்குத் திசையில் காணப்படுவது பூக்கள்.

ஈ. தோட்டத்தின் மேற்குத் திசையில் காணப்படுவது நாய்.

5. இரவில் பூக்கும் மலர்களை அடையாளம் கண்டு (✓) குறியிடுக.

தன் மதிப்பீடு

பகல், இரவு நேரங்களில் என்னால் வானத்தை உற்றுநோக்கி அறிய முடியும்.

என்னால் இரவில் செயலாற்றும் தாவரங்கள் மற்றும் விலங்குகளை அடையாளம் காண முடியும்.

என்னால் திசைகளை அடையாளம் காண முடியும்.