Olympiad Test: Living Organisms And Their Surroundings -2 - Class 6 MCQ

Chlorophyll is the green pigment found in the chloroplasts of plant cells, which is essential for photosynthesis, the process by which plants make food using sunlight, water, and carbon dioxide. Without chlorophyll, the plant cannot perform photosynthesis, even if it has other pigments like red. Therefore, Samantha is correct in stating that the plant cannot make food because it lacks chlorophyll due to its non-green leaves.

Living organisms that excrete uric acid:
- Birds: Birds excrete uric acid as their primary nitrogenous waste product. Uric acid is a waste product of protein metabolism and is formed in the liver. Birds have a unique adaptation in their kidneys that allows them to excrete uric acid in the form of a semi-solid paste, rather than a liquid urine like mammals.
- Lizards: Lizards, including reptiles in general, also excrete uric acid. Similar to birds, reptiles have a highly efficient renal system that enables them to conserve water by excreting uric acid as a paste-like substance.
Conclusion:
The correct answer is A and B both, as both birds and reptiles (which include lizards) excrete uric acid as their primary nitrogenous waste product.

Features of the plant:
- Waxy upper surface of leaves
- Large and flat leaves
- Reduced size of roots
- Long and narrow stems
Explanation:
Based on the given features, we can determine the habitat of the plant:
1. Waxy upper surface of leaves: This feature helps in reducing water loss through transpiration. It is commonly found in plants that grow in dry environments.
2. Large and flat leaves: This characteristic is often observed in plants that need to maximize their surface area for photosynthesis. They are usually found in habitats with ample sunlight.
3. Reduced size of roots: Plants with reduced root size are adapted to habitats where water availability is limited. This adaptation helps them to conserve water effectively.
4. Long and narrow stems: Such stems are commonly found in plants growing in habitats with strong winds. The long and narrow shape helps them to resist wind damage.
Conclusion:
Considering the features mentioned, the plant described in the question is likely to belong to the desert habitat. Desert plants often have waxy leaves to reduce water loss, large flat leaves to maximize photosynthesis, reduced roots to conserve water, and long narrow stems to withstand wind.

The control group in the experiment is the group that serves as a comparison to the test groups. It does not receive any sweetener in its food. The other three test groups consume different amounts of sweetener in their food.
Test groups:
- Group A: This test group receives 10 mg/day of sweetener in their food.
- Group B: This test group receives 50 mg/day of sweetener in their food.
- Group C: This test group does not receive any sweetener in their food.
- Group D: This test group receives extra food, but no sweetener.
Explanation:
- The purpose of having a control group is to provide a baseline for comparison. By not giving any sweetener to the control group, any changes observed in the test groups can be attributed to the sweetener and not other factors.
- Group A and Group B are the test groups that receive different amounts of sweetener in their food. These groups are used to study the effects of different dosages of sweetener.
- Group C is the control group that does not receive any sweetener. By comparing the results of Group C with the test groups, the researchers can determine the impact of the sweetener on various factors.
- Group D is not a test group related to the sweetener. It receives extra food, but no sweetener. This group may serve as a control group for other factors being studied in the experiment.
In conclusion, the control group in this experiment is the one that does not receive any sweetener in their food (Group C).