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Living Things - Plant and Animal Adaptations

Grade 5IB

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

🔑Concepts

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Adaptation is the biological process where organisms evolve features to survive in their environment. These are categorized into structural (physical features) and behavioral (actions).

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Plants perform photosynthesis to create food, represented by the chemical equation: 6CO2+6H2O+light energy→C6H12O6+6O26CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2.

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Xerophytes are plants adapted to dry environments. They often have thick waxy cuticles and spines instead of leaves to reduce the loss of H2OH_2O via transpiration.

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Hydrophytes are aquatic plants that have large air spaces to stay afloat and facilitate the exchange of gases like O2O_2 and CO2CO_2.

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The Surface Area to Volume ratio (SA:VSA:V) is a crucial adaptation factor. Animals in cold climates often have smaller ears and tails to decrease the surface area available for heat loss.

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Camouflage and mimicry are structural adaptations that help organisms avoid predators or sneak up on prey by blending into their surroundings.

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Hibernation is a behavioral adaptation where an animal's metabolic rate drops significantly, reducing the need for energy (glucose, C6H12O6C_6H_{12}O_6) during cold months.

📐Formulae

6CO2+6H2O+light→C6H12O6+6O26CO_2 + 6H_2O + \text{light} \rightarrow C_6H_{12}O_6 + 6O_2

C6H12O6+6O2→6CO2+6H2O+Energy (ATP)C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP)}

Surface Area to Volume Ratio=SAV\text{Surface Area to Volume Ratio} = \frac{SA}{V}

Tchange∝1MassT_{change} \propto \frac{1}{\text{Mass}} (Simplified heat loss concept)

💡Examples

Problem 1:

A desert plant has a thick, fleshy stem. If the stem stores 500500 mL of H2OH_2O and loses 22 mL per day through transpiration, how long can it survive without rain?

Solution:

500 mL2 mL/day=250 days\frac{500\text{ mL}}{2\text{ mL/day}} = 250\text{ days}

Explanation:

Succulent stems are structural adaptations for water storage in arid biomes where H2OH_2O is scarce.

Problem 2:

Explain why a Polar Bear has a small surface area to volume ratio (SA:VSA:V) compared to a Fennec Fox.

Solution:

A smaller SA:VSA:V ratio minimizes the area exposed to the cold, reducing heat loss.

Explanation:

Because heat loss occurs at the surface, larger, rounder bodies (lower SA:VSA:V) retain internal thermal energy more efficiently in temperatures below 0∘C0^{\circ}C.

Problem 3:

Identify the gas released by plants during the day that is essential for animal survival.

Solution:

O2O_2 (Oxygen)

Explanation:

During photosynthesis, plants take in CO2CO_2 and release O2O_2 as a byproduct, which animals use for cellular respiration.