krit.club logo

Growing up with Nature - Growing up with Nature

Grade 4CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

•

Photosynthesis is the process by which green plants make their own food using sunlight, water, and carbon dioxide. The word comes from 'Photo' (light) and 'Synthesis' (putting together).

•

Chlorophyll is the green pigment found in leaves that traps sunlight. It is essential for the production of glucose (C6H12O6C_6H_{12}O_6).

•

Stomata are tiny pores located mostly on the underside of leaves that allow for gas exchange, taking in CO2CO_2 and releasing O2O_2.

•

The life cycle of a butterfly involves four stages: Egg →\rightarrow Larva (Caterpillar) →\rightarrow Pupa (Chrysalis) →\rightarrow Adult Butterfly. This process is called metamorphosis.

•

Interdependence: Plants and animals depend on each other. Plants provide O2O_2 and food, while animals provide CO2CO_2 and help in seed dispersal.

•

Food Chain: A sequence that shows how energy moves from one living thing to another. For example: Grass→Grasshopper→Frog→SnakeGrass \rightarrow Grasshopper \rightarrow Frog \rightarrow Snake.

📐Formulae

Carbon Dioxide+Water→ChlorophyllSunlightGlucose+Oxygen\text{Carbon Dioxide} + \text{Water} \xrightarrow[\text{Chlorophyll}]{\text{Sunlight}} \text{Glucose} + \text{Oxygen}

Total Energy at level n=Energy from level (n−1)×10%\text{Total Energy at level } n = \text{Energy from level } (n-1) \times 10\%

Age of a Tree≈Number of Annual Growth Rings\text{Age of a Tree} \approx \text{Number of Annual Growth Rings}

💡Examples

Problem 1:

If a caterpillar eats 1515 leaves in one day, how many leaves will a group of 88 caterpillars eat in 55 days?

Solution:

15×8×5=600 leaves15 \times 8 \times 5 = 600 \text{ leaves}

Explanation:

First, calculate the leaves eaten by 8 caterpillars in one day: 15×8=12015 \times 8 = 120. Then, multiply by the number of days: 120×5=600120 \times 5 = 600.

Problem 2:

A scientist counts the annual rings of a fallen tree trunk. She finds 4242 dark rings. What is the approximate age of the tree?

Solution:

Age=42 years\text{Age} = 42 \text{ years}

Explanation:

Each pair of light and dark rings typically represents one year of a tree's growth. Therefore, 4242 rings indicate the tree lived for approximately 4242 years.

Problem 3:

During a science experiment, a plant produces 100100 units of Oxygen. If 2020 units are used by the plant itself for respiration at night, how much net Oxygen is released into the atmosphere?

Solution:

100−2080\begin{array}{r} 100 \\ - 20 \\ \hline 80 \end{array}

Explanation:

The net oxygen released is the total oxygen produced during the day minus the oxygen consumed by the plant for its own survival.