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Table 6 shows information about five different organisms - AQA - GCSE Biology - Question 6 - 2022 - Paper 1
Question 6
Table 6 shows information about five different organisms. Table 6 | Organism | Surface area in m² | Volume in m³ | Surface area to volume ratio | |----------|-----... show full transcript
Worked Solution & Example Answer:Table 6 shows information about five different organisms - AQA - GCSE Biology - Question 6 - 2022 - Paper 1
Step 1
Calculate value X in Table 6.
Answer
To find the surface area to volume ratio for organism C, we use the formula:
Using the provided values:
- Surface area for C = 9.96 × 10³ m²
- Volume for C = 1.35 × 10⁻¹⁴ m³
Substituting these values into the formula:
To express this in the required format, round to the nearest whole number, yielding:
X = 74.
Step 2
What is the relationship between the size of an organism and its surface area to volume ratio?
Answer
As size increases, the surface area to volume ratio decreases. This means that larger organisms tend to have less surface area relative to their volume, making it more challenging for them to exchange materials with their environment efficiently.
Step 3
Explain why organism D requires a respiratory system, but organism B does not require a respiratory system.
Answer
Organism D has a larger volume, which results in a smaller surface area to volume ratio. This means that diffusion of gases directly through the skin would be insufficient to meet its metabolic needs, thus requiring a more efficient respiratory system to facilitate gas exchange. In contrast, organism B has a smaller volume and consequently a larger surface area to volume ratio, allowing for adequate gas exchange directly through its skin.
Step 4
Explain why the metabolic rate of organism D is greater than the metabolic rate of organism E.
Answer
Organism D has a larger surface area to volume ratio compared to organism E, which allows it to lose heat more quickly. It also has a greater metabolic demand due to maintaining a warm body temperature, therefore it requires more energy and generates more heat to sustain this. In contrast, organism E has a smaller surface area to volume ratio, leading to lower heat loss and, consequently, a lower metabolic rate.
Step 5
Describe how the alveoli and the villi are adapted to increase absorption.
Answer
Both the alveoli and the villi have adaptations that maximize their surface area for absorption.
Alveoli Adaptations:
- Large Surface Area: The numerous alveoli increase the total surface area for gas exchange.
- Thin Walls: The walls are one cell thick to minimize diffusion distance for gases.
- Rich Blood Supply: They are surrounded by capillaries, facilitating efficient gas exchange with the blood.
Villi Adaptations:
- Microvilli: The presence of microvilli on epithelial cells of the villi further increases the surface area for nutrient absorption.
- Thin Walls: Similar to alveoli, villi also have thin walls to allow efficient transfer of nutrients to the blood.
- Good Blood Supply: Villi have a dense capillary network, ensuring rapid absorption of absorbed nutrients.