Science, Unit 5, Unit 6

 Unit - 5

Life Process

*. Answer the following questions:

(a) What is life process?

Life processes are the basic activities that all living things perform in order to survive. These processes include:

• Respiration: The process by which living things use oxygen to release energy from food.
• Nutrition: The process by which living things take in food and use it to build and repair cells.
• Excretion: The process by which living things remove waste products from their bodies.
• Reproduction: The process by which living things create offspring.
• Growth: The process by which living things increase in size and complexity.
• Development: The process by which living things change over time.

(b) What are the conditions in human life cycle?

The conditions in the human life cycle are:

• Gestation: The period of time from conception to birth, during which the fetus develops inside the mother's womb.
• Infancy: The period of time from birth to about 1 year old, during which the infant grows and develops rapidly.
• Toddlerhood: The period of time from about 1 to 3 years old, during which the toddler learns to walk, talk, and explore their environment.
• Preschool: The period of time from about 3 to 5 years old, during which the preschooler learns basic skills in reading, writing, and arithmetic.
• School age: The period of time from about 5 to 18 years old, during which the child attends school and learns academic and social skills.
• Adolescence: The period of time from about 13 to 19 years old, during which the adolescent experiences physical and emotional changes.
• Adulthood: The period of time from about 19 to 65 years old, during which the adult works, raises a family, and contributes to society.
• Old age: The period of time from about 65 years old until death, during which the elderly person may experience physical and cognitive decline.

(c) Write the names of the different stages in the life cycle of a pigeon.

The different stages in the life cycle of a pigeon are:

• Egg: The egg is the fertilized ovum of a pigeon. It is laid by the female pigeon and incubated by the male pigeon.
• Chick: The chick is the young pigeon that hatches from the egg. It is helpless and dependent on its parents for food and care.
• Juvenile: The juvenile is the pigeon that has grown feathers and is able to fly. It is still dependent on its parents for food and care, but it is becoming more independent.
• Adult: The adult pigeon is a fully mature bird that is able to reproduce. It is no longer dependent on its parents for food or care.

(d) What are the stages in the life cycle of an insect?

The stages in the life cycle of an insect are:

• Egg: The egg is the fertilized ovum of an insect. It is laid by the female insect and hatched into a larva.
• Larva: The larva is the immature form of an insect. It is usually worm-like and has chewing mouthparts. It feeds on plants or other animals.
• Pupa: The pupa is the stage in which an insect undergoes metamorphosis. It is a non-feeding stage in which the insect's body changes into an adult.
• Adult: The adult is the final stage in the life cycle of an insect. It is usually winged and has biting or sucking mouthparts. It mates and lays eggs, continuing the life cycle.

(e) Name the different stages in the life cycle of beans.

The different stages in the life cycle of beans are:

• Seed: The seed is the fertilized ovule of a bean plant. It is dormant until it is planted in the ground.
• Germination: Germination is the process by which a seed begins to grow. It is triggered by water and warmth.
• Seedling: The seedling is the young plant that emerges from the seed. It has two cotyledons, which are the first leaves of the plant.
• Vegetative stage: The vegetative stage is the period of time when the plant is growing and developing its roots, stems, and leaves.
• Flowering stage: The flowering stage is the period of time when the plant blooms and produces flowers.
• Fruiting stage: The fruiting stage is the period of time when the plant produces fruits and seeds.

(f) Write the name of the situation seen in Rayo's life cycle.

The situation seen in Rayo's life cycle is called metamorphosis. Metamorphosis is the process by which an animal undergoes a dramatic change in form during its development. In Rayo's case, he starts out as a caterpillar, then he undergoes a metamorphosis and becomes a butterfly.

 Unit - 6

Matter

Water

*. Answer the following questions:

(a) Write two important properties of water.

Two important properties of water are:

1. High specific heat capacity: Water has a high specific heat capacity, which means it can absorb and store a large amount of heat energy before its temperature increases significantly. This property helps regulate temperature on Earth and contributes to the stability of aquatic ecosystems.
2. Universal solvent: Water is often referred to as the universal solvent because it has the ability to dissolve a wide range of substances. This property allows water to transport nutrients and minerals in biological systems and facilitates various chemical reactions.

(b) How can the three states of water be changed from one to another? Explain with chart.

The three states of water, solid (ice), liquid, and gas (water vapor), can be changed from one to another through the processes of melting, freezing, evaporation, condensation, and sublimation. Here is a chart explaining these state changes:

State Change	Description
Melting	The process of changing a solid into a liquid.
Freezing	The process of changing a liquid into a solid.
Evaporation	The process of changing a liquid into a gas.
Condensation	The process of changing a gas into a liquid.
Sublimation	The process of changing a solid directly into a gas or vice versa.

(c) Distinguish between evaporation and liquefaction.

Evaporation and liquefaction are two different processes:

Evaporation: Evaporation is the process by which a liquid changes into a gas at a temperature below its boiling point. It occurs at the surface of the liquid and involves the escape of individual molecules. Evaporation can happen at any temperature and occurs more rapidly with higher temperatures and increased surface area.

Liquefaction: Liquefaction is the process by which a gas or vapor changes into a liquid. It occurs when the gas or vapor is cooled below its condensation point or when it is subjected to high pressure. Liquefaction involves the clustering and bonding of gas molecules to form a liquid.

(d) Rohan started playing by placing the teapot on the stove to make three cups of tea And forget. Looking after a while, there is only one cup of tea left. like this Mention the reason.

The reason for Rohan starting with three cups of tea on the stove but finding only one cup left later could be that the remaining tea evaporated due to the heat. As the teapot was placed on the stove, the heat caused the water in the tea to evaporate, converting it into water vapor that escaped into the air. This process continued until only one cup of tea was left.

(e) Draw a neat picture of the water cycle and name it.

answer yourself

(f) A fox pours equal amounts of water into two bowls, one open and the other open

She keeps the lid and leaves it in the sun. After a few hours, both the bowls of water

What is the difference in quality? Explain with reasons.

The difference in quality between the two bowls of water poured by the fox, one being open and the other covered, is due to evaporation. In the open bowl, the water is exposed to the sun and air, leading to evaporation. As water evaporates, it undergoes a phase change from liquid to gas, leaving behind impurities and minerals, resulting in a higher concentration of contaminants in the remaining water. The covered bowl, on the other hand, prevents or reduces evaporation, so the water quality remains relatively unchanged.

(g) What are the technologies that operate using water power? the name write

Some technologies that operate using water power are:

1. Hydropower: The generation of electricity using the energy of flowing or falling water, typically through the use of dams and turbines.
2. Watermills: Traditional mills that utilize the mechanical energy of water to grind grains or perform other mechanical tasks.
3. Tidal power: Harnessing the energy from the tides to generate electricity by using tidal barrages or tidal turbines.
4. Wave power: Utilizing the kinetic energy of ocean waves to generate

(h) Savita picked up the clothes that had dried in Kausi on a winter day will forget When he woke up in the morning, his clothes were completely wet. that It didn't rain that night. How could Savita's clothes be wet?

If Savita's clothes dried in Kausani on a winter day and became wet overnight without any rainfall, it is possible that the moisture in the air condensed on the clothes due to a decrease in temperature during the night. This phenomenon is known as dew. When the temperature drops, the air loses its ability to hold moisture, causing it to condense on surfaces, including the clothes that were hung outside. Therefore, even without rain, the clothes could become wet due to dew formation.

(i) What is water pollution? What can you do to prevent water pollution around your home? What do you pay attention to?

Water pollution refers to the contamination of water bodies such as rivers, lakes, oceans, and groundwater, usually as a result of human activities. It can occur due to the discharge of industrial waste, sewage, agricultural runoff, oil spills, and improper disposal of chemicals.

To prevent water pollution around your home, you can take the following measures:

1. Properly dispose of household chemicals: Avoid pouring chemicals down the drain or toilet. Instead, dispose of them at designated collection centers or follow the guidelines provided by local authorities.
2. Use eco-friendly cleaning products: Choose environmentally friendly and biodegradable cleaning products that do not contain harmful chemicals.
3. Minimize pesticide and fertilizer use: When using pesticides or fertilizers in your garden, follow the instructions carefully to avoid excessive use or runoff into water bodies.
4. Properly maintain your septic system: If you have a septic system, ensure regular inspections and maintenance to prevent leaks or seepage that can contaminate groundwater.
5. Conserve water: Practice water conservation by fixing leaks, using water-efficient appliances, and being mindful of water usage in daily activities.

Air

*. Answer the following questions:

(a) Write the utility of air in daily life.

The utility of air in daily life is manifold. Some important uses of air include:

1. Breathing: Air provides oxygen, which is essential for the survival of all living organisms, including humans. We breathe in air to take in oxygen and release carbon dioxide.

2. Transportation: Air is used as a medium for transportation through airplanes, helicopters, and other aircraft. It allows for rapid travel across long distances and enables global connectivity.

3. Weather patterns: Air plays a crucial role in the formation of weather patterns. It carries moisture, creates wind currents, and influences atmospheric pressure, leading to the formation of clouds, rain, and other weather phenomena.

4. Ventilation: Air circulation helps in maintaining a comfortable and healthy indoor environment. Proper ventilation brings fresh air into buildings, removes stale air, and helps regulate temperature and humidity levels.

5. Combustion: Air is necessary for the process of combustion, such as burning fuel for cooking, heating, and electricity generation.

(b) Even though there is air around us, we cannot see it, why?

We cannot see air because it is a transparent gas. The molecules that make up air, mainly nitrogen, oxygen, carbon dioxide, and other trace gases, are much smaller than the wavelengths of visible light. When light encounters these molecules, it passes through them without being absorbed or reflected significantly. As a result, our eyes do not perceive the presence of air unless it carries dust, smoke, or other visible particles.

(c) What is air pollution?

Air pollution refers to the contamination of the air by harmful substances or pollutants that can have adverse effects on living organisms and the environment. It occurs when pollutants are released into the air from various sources, leading to a degradation of air quality.

(d) What human activities cause air pollution?

Various human activities contribute to air pollution, including:

1. Industrial emissions: Industrial processes, such as the burning of fossil fuels in power plants, factories, and refineries, release pollutants into the air, including sulfur dioxide, nitrogen oxides, and particulate matter.

2. Vehicle emissions: The burning of gasoline and diesel fuels in vehicles releases pollutants such as carbon monoxide, nitrogen oxides, volatile organic compounds (VOCs), and particulate matter.

3. Agricultural activities: Agricultural practices, such as the use of fertilizers and pesticides, livestock farming, and open burning of agricultural waste, can release pollutants like ammonia, methane, and dust particles.

4. Residential activities: Domestic sources of air pollution include the burning of wood and other solid fuels for cooking and heating, improper waste management, and use of certain household products containing volatile chemicals.

5. Deforestation and biomass burning: The clearing of forests through deforestation and the burning of biomass for land clearance or cooking purposes release large amounts of smoke, particulate matter, and carbon dioxide into the air.

(e) What is the effect of air pollution on the earth's environment?

Air pollution has several negative effects on the Earth's environment, including:

1. Climate change: Air pollution contributes to the accumulation of greenhouse gases in the atmosphere, leading to global warming and climate change.

2. Acid rain: Emissions of sulfur dioxide and nitrogen oxides combine with atmospheric moisture to form acid rain. Acid rain can damage vegetation, freshwater ecosystems, and infrastructure.

3. Ozone depletion: Certain pollutants, such as chlorofluorocarbons (CFCs), can deplete the ozone layer in the upper atmosphere, leading to increased ultraviolet (UV) radiation reaching the Earth's surface.

4. Smog formation: Air pollution can contribute to the formation of smog, especially in urban areas with high levels of vehicle emissions and industrial activities. Smog reduces visibility and poses health risks to humans and other organisms.

(f) How does air pollution affect humans?

Air pollution can have severe impacts on human health. Some effects include:

1. Respiratory problems: Air pollution can worsen existing respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD). It can also lead to the development of respiratory infections, bronchitis, and other lung diseases.

2. Cardiovascular issues: Exposure to air pollution has been linked to an increased risk of heart attacks, strokes, and other cardiovascular diseases.

3. Allergies and irritations: Pollutants in the air can trigger allergies, cause eye and throat irritations, coughing, and sneezing.

4. Reduced lung function: Prolonged exposure to air pollution can result in reduced lung function, especially in children and the elderly.

5. Increased cancer risk: Certain air pollutants, such as particulate matter and hazardous chemicals, have been associated with an increased risk of lung cancer and other respiratory-related cancers.

(g) Anu tried to make a circle of paper and spin it on a windless day. But he did not turn around. What is the reason for this?

The reason Anu's paper circle did not spin on a windless day could be the lack of air movement. For the paper circle to spin, it requires air to exert a force on its surface. Wind or air currents create this force by applying pressure unevenly on the paper, causing it to rotate. In the absence of any wind or air movement, there is no force acting on the paper to initiate its spinning motion.

(h) If there is air pollution in your neighborhood, it affects your life What will be the effect? What efforts can be made to minimize it?

If there is air pollution in your neighborhood, it can have various negative effects on your life and well-being. Some effects include:

1. Health issues: Air pollution can lead to respiratory problems, allergies, and other health conditions, affecting the overall quality of life for individuals in the area.

2. Reduced outdoor activities: Poor air quality may discourage people from spending time outdoors, impacting recreational activities, exercise, and overall enjoyment of outdoor spaces.

3. Environmental degradation: Air pollution can harm local ecosystems, vegetation, and wildlife, leading to ecological imbalances and reduced biodiversity.

Efforts to minimize air pollution in your neighborhood can include:

1. Supporting clean energy sources: Encourage the use of renewable energy sources and advocate for the transition away from fossil fuels in power generation and transportation.

2. Promoting sustainable transportation: Encourage walking, cycling, or the use of public transportation to reduce vehicle emissions. Carpooling and using electric vehicles can also help minimize air pollution.

3. Reducing household emissions: Use energy-efficient appliances, properly insulate homes, and opt for clean and renewable energy sources for heating and cooking. Avoid burning solid fuels indoors and practice responsible waste management.

4. Planting trees and creating green spaces: Trees and vegetation can help filter pollutants from the air and improve local air quality. Support tree planting initiatives and encourage the creation of green spaces in your neighborhood.

5. Advocating for regulations and policies: Stay informed about local air quality regulations and support measures to reduce air pollution. Engage with local authorities and community organizations to raise awareness and push for stricter pollution control measures.