Tissues chapter 6 - Test - Class 10 MCQ

Answer:
To move your organs like hands and legs while doing work and running, skeletal muscles contract and pull the tendons to move the bones. Here is a detailed explanation:
Skeletal Muscles:
- Skeletal muscles are attached to the bones and allow voluntary movement of the body.
- They are responsible for movements such as walking, running, lifting, and pushing.
- Skeletal muscles are made up of long, cylindrical cells called muscle fibers.
Tendons:
- Tendons are strong, fibrous connective tissues that connect muscles to bones.
- They transmit the force generated by the muscle to the bones, allowing movement.
How Movement Occurs:
- When you want to move, your brain sends signals to the skeletal muscles.
- The skeletal muscles then contract, which means they shorten in length and generate force.
- This force is transmitted through the tendons to the bones, causing movement.
Example:
- When you run, your brain sends signals to the skeletal muscles in your legs.
- These muscles contract and pull on the tendons attached to the bones in your legs.
- The force generated by the muscles is transmitted through the tendons to the bones, allowing your legs to move and propel you forward.
So, in conclusion, skeletal muscles contract and pull the tendons to move the bones while doing work and running.

Common Feature of Chordates:
Chordates are a group of animals that possess certain key characteristics. One common feature of chordates is the presence of a notochord. Here, we will discuss this feature in detail:
1. Presence of Notochord:
- The notochord is a flexible rod-like structure that runs along the length of the body.
- It provides support and serves as an axis for muscle attachment.
- In some chordates, the notochord is present only during embryonic development and is later replaced by a vertebral column (backbone).
- In others, such as the jawless fish, the notochord persists throughout life.
- The notochord is a defining characteristic of chordates and is present in all members of this group, at least during some stage of their life cycle.
Other Features of Chordates:
2. Presence of Triploblastic Condition:
- Chordates, like many other animals, are triploblastic, meaning their bodies are composed of three germ layers: ectoderm, endoderm, and mesoderm.
- The ectoderm gives rise to the outer covering and nervous system.
- The endoderm forms the lining of the digestive and respiratory systems.
- The mesoderm gives rise to muscles, connective tissues, and other internal structures.
3. Presence of Coelom:
- Chordates have a coelom, which is a fluid-filled body cavity located between the body wall and the internal organs.
- The coelom provides space for organ development, movement, and protection.
4. Presence of Gill Pouches:
- Many chordates have gill pouches or slits in their pharynx region.
- These pouches are responsible for respiration in aquatic chordates, allowing them to extract oxygen from the water.
- In some chordates, the gill pouches are modified for other functions, such as feeding or sound production.
In conclusion, while chordates share several common features, the presence of a notochord is a defining characteristic of this group. The notochord, along with other features like triploblastic condition, coelom, and gill pouches, distinguishes chordates from other animal groups.

Incorrect Statement: D: Fishes, amphibians and reptiles are oviparous.
Explanation:
- Fishes, amphibians, and reptiles are not exclusively oviparous. Some species within these groups are oviparous, while others are viviparous or even exhibit other forms of reproduction.
- Oviparous refers to animals that lay eggs and have external fertilization.
- While many fish species lay eggs and exhibit external fertilization, there are some exceptions. For example, some species of sharks and rays give birth to live young in a process called ovoviviparity or viviparity.
- Similarly, amphibians such as some species of salamanders and frogs can be oviparous or viviparous, depending on the species.
- Reptiles also show a range of reproductive strategies. While most reptiles are oviparous, there are some exceptions. Some reptiles, such as certain species of snakes and lizards, give birth to live young (viviparity).
Therefore, statement D is incorrect as it generalizes all fishes, amphibians, and reptiles as oviparous, which is not accurate.

Adaptations of the frog that differentiate it from the fish:

• Ability to live in water also: While fish are exclusively aquatic animals, frogs have the ability to live both in water and on land. This adaptation allows frogs to survive in a variety of habitats, including freshwater bodies, wetlands, and even terrestrial environments.


• Lays eggs in water: Unlike fish that release eggs into the water, frogs lay their eggs in water. This adaptation helps protect the eggs from desiccation and provides a suitable environment for their development.


• Have a streamlined body: Frogs have a streamlined body shape that allows them to move efficiently in both water and on land. This adaptation enables frogs to swim and navigate through water, as well as leap and hop on land.


• Presence of mucous glands in the skin: Frogs have specialized mucous glands in their skin that secrete a slimy substance. This adaptation helps keep their skin moist and protects them from drying out. It also aids in respiration, as frogs can absorb oxygen through their skin when submerged in water.

In summary, the adaptations of frogs that differentiate them from fish include their ability to live in both water and on land, laying eggs in water, having a streamlined body, and the presence of mucous glands in their skin. These adaptations allow frogs to thrive in a wide range of environments and perform various biological functions.