All questions of Living Things for Class 5 Exam

An invertebrate is an animal that does not have a backbone or spinal column. Invertebrates make up the majority of animal species on Earth and can be found in a wide range of habitats, including the ocean, forests, and even in our own backyards.

The correct answer to the question is option 'D', which is the butterfly. Let's explain why the butterfly is an example of an invertebrate.

- Characteristics of Invertebrates:
Invertebrates can vary greatly in size, shape, and behavior, but they all share the common characteristic of lacking a backbone. Some key characteristics of invertebrates include:
1. No Backbone: Unlike vertebrates (animals with backbones), invertebrates do not possess a spinal column made up of individual vertebrae.
2. Exoskeleton or Soft Body: Invertebrates may have a hard exoskeleton made of chitin, like insects, or a soft body, like squids or jellyfish.
3. Diverse Forms: Invertebrates exhibit a wide range of body forms, including worms, insects, spiders, mollusks, and more.

- The Example of a Butterfly:
Butterflies are insects, and insects are a type of invertebrate. Here's why butterflies fit the criteria of an invertebrate:
1. Lack of Backbone: Butterflies do not have a backbone. Instead, they have a segmented body supported by an exoskeleton.
2. Exoskeleton: Like all insects, butterflies have an exoskeleton, which is a hard outer covering that protects and supports their bodies. The exoskeleton is made of chitin and provides structure and protection for the butterfly.
3. Jointed Legs and Segmented Body: Butterflies have six jointed legs and a segmented body, both of which are common characteristics of insects.

In conclusion, the butterfly is an example of an invertebrate because it lacks a backbone, has an exoskeleton, and possesses other key characteristics of insects. It is important to note that other options given in the question, such as the snake, frog, and fish, are all examples of vertebrates as they have backbones.

Respiration
Respiration is the process by which living organisms release energy from food. It is a series of chemical reactions that take place in the cells of organisms, converting glucose and oxygen into carbon dioxide, water, and energy in the form of ATP (adenosine triphosphate). This energy is then used by the cells to carry out various functions and activities necessary for survival.

Process of Respiration
Respiration occurs in two main stages:
1. Glycolysis: This is the initial stage of respiration, which occurs in the cytoplasm of the cell. During glycolysis, glucose is broken down into two molecules of pyruvate. This process does not require oxygen and produces a small amount of ATP.
2. Krebs Cycle and Electron Transport Chain: The second stage of respiration takes place in the mitochondria. The pyruvate molecules produced in glycolysis are further broken down in the Krebs cycle and converted into carbon dioxide. This stage is also known as the citric acid cycle. The energy released during these reactions is captured in the form of high-energy electrons. These electrons are then passed along the electron transport chain, which results in the production of a large amount of ATP.

Importance of Respiration
Respiration is essential for living organisms as it provides the energy needed for various biological processes. Some key points regarding the importance of respiration are:
- It is the primary source of energy for the cells and enables them to carry out their functions.
- It allows organisms to perform essential activities such as movement, growth, and reproduction.
- Respiration is necessary for the synthesis of molecules required for cell maintenance, repair, and growth.
- It helps in the removal of waste products, such as carbon dioxide, from the body.

Difference between Photosynthesis and Respiration
Although both photosynthesis and respiration are vital processes for living organisms, they are fundamentally different. Here are some key differences between the two:
- Photosynthesis is the process by which plants, algae, and some bacteria convert sunlight, carbon dioxide, and water into glucose and oxygen. It occurs in chloroplasts and requires sunlight. Respiration, on the other hand, occurs in all living organisms and releases energy from food.
- Photosynthesis is an anabolic process that builds glucose molecules, while respiration is a catabolic process that breaks down glucose molecules.
- Photosynthesis occurs in the presence of light, whereas respiration occurs constantly, both in light and darkness.
- The end products of photosynthesis are glucose and oxygen, while the end products of respiration are carbon dioxide, water, and ATP.

In conclusion, respiration is the process by which energy is released from food in living organisms. It involves the breakdown of glucose and oxygen to produce carbon dioxide, water, and ATP. Respiration is essential for the survival and functioning of all living organisms.

Fireflies, also known as lightning bugs, are the living organisms capable of generating their own light. This ability is known as bioluminescence. Let's explore this in detail:

Bioluminescence in Fireflies:
- Fireflies are a type of beetle that possesses the unique ability to produce light through a chemical reaction in their bodies.
- The process of bioluminescence in fireflies involves a substance called luciferin, which reacts with an enzyme called luciferase in the presence of oxygen, ATP (adenosine triphosphate), and magnesium ions.
- The reaction between luciferin and luciferase produces an excited state of luciferin, which, upon returning to its ground state, releases energy in the form of light.
- The light emitted by fireflies is usually yellow or green and is used for various purposes such as attracting mates, communicating, and warning predators.

Function of Bioluminescence in Fireflies:
- Mating: Fireflies use their light-producing ability to attract mates. Males fly and emit specific light patterns or flashes to signal their presence to females. In response, females of the same species may produce a different pattern of light flashes to communicate their receptivity to mating.
- Defense: Some firefly species use their bioluminescence as a defense mechanism. They emit a prolonged glow to warn predators that they are distasteful or toxic.
- Species Recognition: Each firefly species has its own unique pattern of light flashes, allowing individuals to recognize and distinguish members of their own species from others.
- Camouflage: Firefly larvae, also known as glowworms, produce light to attract prey. They typically reside in damp areas and emit a faint glow to lure insects, small invertebrates, or other suitable food sources.

Conclusion:
Fireflies are fascinating creatures that possess the ability to generate their own light through a chemical reaction. This bioluminescence serves various purposes, including attracting mates, communication, defense, and hunting. By understanding the mechanisms and functions of bioluminescence in fireflies, we gain insight into the incredible diversity of adaptations found in the natural world.