Class 7 Science Worksheet (Mix-2) worksheet - Free Printable

Let's solve the worksheet step by step and provide explanations for each answer.

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1. Yeast breaks down glucose into _______ and carbon dioxide.

- Answer: Alcohol
- Explanation: Yeast undergoes a process called fermentation, where it breaks down glucose (a sugar) into alcohol and carbon dioxide. This is a common process used in baking and brewing.

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2. The accumulation of _______ causes muscle cramps.

- Answer: Lactic acid
- Explanation: When muscles are overworked or lack oxygen, they produce lactic acid as a byproduct of anaerobic respiration. The buildup of lactic acid can cause muscle cramps.

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3. All changes in the weather are caused by the _______.

- Answer: Atmosphere
- Explanation: Weather refers to short-term atmospheric conditions such as temperature, humidity, wind, and precipitation. These changes are driven by processes occurring in the Earth's atmosphere.

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4. The average weather pattern taken over a long time is called the _______ of that place.

- Answer: Climate
- Explanation: Climate refers to the long-term patterns of weather in a particular region, typically averaged over 30 years or more. It includes factors like temperature, precipitation, and wind patterns.

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5. The Earth is heated more near the equator or poles?

- Answer: Equator
- Explanation: The Earth receives more direct sunlight near the equator, leading to higher temperatures. Near the poles, sunlight is more indirect due to the curvature of the Earth, resulting in colder temperatures.

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6. Rain with storm and lightning is called _______.

- Answer: Thunderstorm
- Explanation: A thunderstorm is a storm characterized by heavy rain, strong winds, lightning, and thunder. Lightning occurs due to electrical discharges within clouds.

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7. On heating, air expands and occupies _______ space. (More/Less)

- Answer: More
- Explanation: When air is heated, its molecules move faster and spread out, causing the air to expand and occupy a larger volume (more space).

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8. Increased wind speed is accompanied by _______ air pressure. (Reduced/Increased)

- Answer: Reduced
- Explanation: According to Bernoulli's principle, as wind speed increases, air pressure decreases. This is why fast-moving air (like in tornadoes or hurricanes) has lower pressure compared to still air.

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9. Penguins are good swimmers because their body is _______.

- Answer: Streamlined
- Explanation: Penguins have a streamlined body shape, which reduces water resistance and allows them to swim efficiently. Their flippers also help propel them through water.

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10. The lion-tailed macaque is also known as _______.

- Answer: Wanderoo
- Explanation: The lion-tailed macaque is a primate native to the Western Ghats of India. It is also commonly referred to as the "Wanderoo."

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Final Answers:

1. Alcohol
2. Lactic acid
3. Atmosphere
4. Climate
5. Equator
6. Thunderstorm
7. More
8. Reduced
9. Streamlined
10. Wanderoo

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Boxed Final Answer:
\boxed{
\begin{array}{l}
1. \text{Alcohol} \\
2. \text{Lactic acid} \\
3. \text{Atmosphere} \\
4. \text{Climate} \\
5. \text{Equator} \\
6. \text{Thunderstorm} \\
7. \text{More} \\
8. \text{Reduced} \\
9. \text{Streamlined} \\
10. \text{Wanderoo} \\
\end{array}
}