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Living Creatures: Exploring their Characteristics - Life Cycle of Animals

Grade 6CBSE

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

🔑Concepts

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Reproduction: It is the biological process by which living organisms produce young ones of their own kind. This ensures the survival of a species SS over successive generations nn.

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Oviparous Animals: Animals that reproduce by laying eggs. Examples include birds, fish, and reptiles. The embryo develops inside the eggshell until it is ready to hatch.

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Viviparous Animals: Animals that give birth to fully formed young ones. Mammals such as humans, cows, and lions fall into this category.

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Metamorphosis: A biological process involving distinct stages where the young organism looks completely different from the adult. The transformation can be represented as a series of morphological changes.

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Life Cycle of a Butterfly: It consists of four stages: Egg→Larva (Caterpillar)→Pupa (Chrysalis)→Adult\text{Egg} \rightarrow \text{Larva (Caterpillar)} \rightarrow \text{Pupa (Chrysalis)} \rightarrow \text{Adult}.

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Life Cycle of a Frog: It involves stages: Egg→Tadpole (Larva)→Adult Frog\text{Egg} \rightarrow \text{Tadpole (Larva)} \rightarrow \text{Adult Frog}. Tadpoles use gills for respiration, while adults use lungs and skin.

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Nymph: The young stage of insects like cockroaches and grasshoppers that resembles the adult but is smaller and lacks wings. They undergo 'molting' to grow.

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Incubation: The process of keeping eggs warm (often using body heat) to allow the embryo to develop at a constant temperature TT.

📐Formulae

Life Cycle (Complete Metamorphosis):Egg→Larva→Pupa→Adult\text{Life Cycle (Complete Metamorphosis)}: \text{Egg} \rightarrow \text{Larva} \rightarrow \text{Pupa} \rightarrow \text{Adult}

Life Cycle (Incomplete Metamorphosis):Egg→Nymph→Adult\text{Life Cycle (Incomplete Metamorphosis)}: \text{Egg} \rightarrow \text{Nymph} \rightarrow \text{Adult}

Incubation Period(t)=thatch−tlaid\text{Incubation Period} (t) = t_{\text{hatch}} - t_{\text{laid}}

💡Examples

Problem 1:

A butterfly larva (caterpillar) eats leaves and increases its weight significantly. If a larva starts at 0.5 g0.5\text{ g} and grows to 5.0 g5.0\text{ g}, calculate the growth factor GG.

Solution:

G=5.0 g0.5 g=10G = \frac{5.0\text{ g}}{0.5\text{ g}} = 10

Explanation:

The growth factor represents how many times the larva has increased its initial mass during the larval stage before entering the pupa stage.

Problem 2:

Identify the respiratory organ of a tadpole and an adult frog.

Solution:

Tadpole→Gills, Adult Frog→Lungs/Skin\text{Tadpole} \rightarrow \text{Gills}, \text{ Adult Frog} \rightarrow \text{Lungs/Skin}

Explanation:

During metamorphosis, the frog's physiology changes from an aquatic-breathing organism (using gills) to a terrestrial/amphibian breather (using lungs and moist skin).

Problem 3:

A bird's egg requires a constant incubation temperature of 37∘C37^{\circ}C. If the ambient temperature is 25∘C25^{\circ}C, find the temperature difference ΔT\Delta T the parent must provide.

Solution:

37−2512\begin{array}{r} 37 \\ - 25 \\ \hline 12 \end{array} So, ΔT=12∘C\Delta T = 12^{\circ}C.

Explanation:

The parent bird sits on the egg to transfer body heat, covering the gap between the environment and the required development temperature.