Animal Diversity – 1 (VSAQs)
Zoology-1 | 3. Animal Diversity-1 – VSAQs:
Welcome to VSAQs in Chapter 3: Animal Diversity-1. This page includes the most important FAQs from previous exams. Each answer is provided in simple English and presented in the exam format. Use these answers to strengthen your understanding and aim for top marks in your final exams.
VSAQ-1: What are the functions of the canal system of sponges?
Imagine a sponge as a bustling city with a network of canals, much like a city’s water system. The canal system in sponges is essential for their survival, and it performs three key functions:
- Collecting and Distributing Food Particles: Think of the canals as delivery routes. They help gather tiny food particles from the water and transport them throughout the sponge’s body, ensuring it gets the nutrients it needs to stay healthy.
- Facilitating Gas Exchange: Just like a city needs fresh air, sponges need to exchange gases. The canal system allows oxygen to enter and carbon dioxide to leave, keeping the sponge’s cells well-oxygenated and functional.
- Removing Waste Products: The canals also act like waste management systems, helping to carry away waste materials from the sponge’s body, so it doesn’t get clogged up with unwanted substances.
VSAQ-2: What is metagenesis? Animals belonging to which phylum exhibit metagenesis?
Metagenesis is a bit like having two different modes in a single life cycle. Imagine you could switch between two different ways of living: one way of reproducing and another way of growing and maturing. This is what metagenesis is all about—alternating between sexual and asexual phases.
This fascinating process is seen in animals from the phylum Cnidaria. For instance, jellyfish and corals show metagenesis. They can switch between two forms: one that reproduces sexually and one that reproduces asexually, allowing them to thrive in different environments.
VSAQ-3: What are the excretory cells of flatworms called? What is the other important function of these specialized cells?
In flatworms, the excretory cells are known as flame cells or protonephridia. Picture these cells as tiny cleaning crews inside the flatworm. Their main job is to remove metabolic waste from the body, similar to how our kidneys filter waste from our blood.
But flame cells do more than just clean up. They also help with osmoregulation, which is like maintaining the right balance of water and salts in the flatworm’s body. This keeps the flatworm’s internal environment stable, which is crucial for its survival.
VSAQ-4: Distinguish between amphids and phasmids.
Imagine a nematode as a tiny creature equipped with specialized sensors:
- Amphids are like the nose of a nematode. Located around the mouth, these are depressions in the cuticle that act as chemoreceptors, helping the nematode sense chemicals in its environment, much like how we smell food.
- Phasmids are located at the posterior end of some nematodes, and they act like sensor organs or additional sensors. They might also be involved in detecting chemicals, providing extra sensory information.
VSAQ-5: What is botryoidal tissue?
Botryoidal tissue is quite unique and can be imagined as a specialized organ system within leeches. Picture it as a cluster of grapes filling up the leech’s body cavity. This tissue serves several important functions:
- Excretion: Like a waste disposal unit, it helps get rid of metabolic waste.
- Storage: It stores essential minerals like iron and calcium, which are important for the leech’s health.
- Revascularization: If the leech gets injured, this tissue helps in repairing and regenerating the damaged areas, ensuring the leech can continue to function properly.
VSAQ-6: Which arthropod is called a ‘living fossil’? Name its respiratory organs.
Imagine a creature that seems to have traveled through time, unchanged for millions of years. That’s the Limulus, or king crab, often referred to as a “living fossil.” Just like ancient machinery that still functions well today, Limulus has been around since the time of dinosaurs.
This amazing arthropod uses book gills for breathing. These gills are like pages in a book, arranged in stacks and located on the underside of the king crab’s body. They work together to help the crab extract oxygen from the water, just as our lungs help us breathe air.
VSAQ-7: What is the function of radula? Give the name of the group of molluscs which do not possess a radula.
Imagine a mollusc with a tiny, rough tongue that scrapes food off surfaces—this is what the radula does. It’s a special feeding organ used by many molluscs, like snails, to scrape and gather food from their surroundings.
However, not all molluscs have this tool. The group of molluscs that don’t possess a radula is called Bivalvia (or Pelecypoda). These include clams and oysters, which filter feed by drawing in water and capturing tiny food particles rather than scraping them off surfaces.
VSAQ-8: What is Aristotle’s lantern? Give one example of an animal possessing it.
Imagine a sea urchin with a high-tech, multi-tool system inside its mouth. This complex feeding structure is known as Aristotle’s lantern. It consists of five jaw-like parts that help the sea urchin scrape and chew its food, much like a sophisticated set of kitchen utensils.
An example of an animal with Aristotle’s lantern is the Echinus, a type of sea urchin. This unique structure allows Echinus to feed on algae and other materials on the ocean floor.
VSAQ-9: What is the essential difference between the larvae and adults of echinoderms, symmetry wise?
Think of echinoderms as having two different “designs” for their life stages. As larvae, echinoderms like starfish have bilateral symmetry, which means they look the same on either side if you draw a line down the middle. It’s a bit like a butterfly’s wings that mirror each other.
However, as they grow into adults, they switch to pentamerous radial symmetry, where their bodies are arranged around a central point in a star-like pattern. Imagine a starfish with arms spreading out from the center—this radial symmetry helps them interact with their environment from all directions.
VSAQ-10: What are the two chief morphological ‘body forms’ of cnidarians? What are their chief functions?
Cnidarians, such as jellyfish and corals, have two main body forms, each with a unique job:
- Medusa Form: This is the jellyfish-like shape, with a bell or umbrella-like body that floats freely in the water. Its main job is reproduction—it releases eggs and sperm into the water to create new cnidarians.
- Polyp Form: Picture a sea anemone with its tube-like body anchored to the ocean floor. This form is primarily for feeding. The polyp uses its tentacles to catch food and bring it to its mouth, living a more stationary life compared to its free-swimming counterpart.
VSAQ-11: What do you call the locomotor structures of Nereis? Why is Nereis called a polychaete?
Think of Nereis as having tiny, specialized “legs” along its body. These are called parapodia, which help the worm move through its aquatic environment. Each parapodium is equipped with many small bristles known as setae. The name polychaete reflects this feature, with “poly” meaning many and “chaeta” meaning bristle. So, Nereis is called a polychaete because it has lots of these bristle-covered “legs” to help it move around and grab onto surfaces.
VSAQ-12: What do you call the first and second pairs of cephalic appendages of a scorpion?
Imagine a scorpion’s face, which is equipped with specialized tools for grabbing and sensing. The first pair of appendages are called chelicerae—these are like pincers or claws used to grasp and chew food. The second pair are called pedipalps, which look like extra “arms” and help the scorpion handle its food and sense its surroundings.
VSAQ-13: What are the respiratory structures of Limulus and Palamnaeus respectively?
Imagine Limulus (the king crab) and Palamnaeus (a scorpion) needing different types of breathing gear. Limulus uses book gills, which look like stacked pages and help it breathe underwater. On the other hand, Palamnaeus has book lungs, which are more like leaf-like structures inside its body that allow it to breathe air.
VSAQ-14: What are antennae? What is the arthropod group without antennae?
Antennae are like the “feelers” or “antenna” on the heads of arthropods. They help these creatures sense their surroundings, much like how we use our hands to explore the world around us. However, not all arthropods have antennae. The group without antennae is the Subphylum Chelicerata, which includes spiders and scorpions. They use other structures for sensing their environment.
VSAQ-15: What is the other name for the gill of a mollusc? What is the function of osphradium?
The gill of a mollusc, like a clam or snail, is called a ctenidium. Think of it as the mollusc’s built-in gill for breathing underwater. The osphradium is a special organ found in some molluscs. It acts like a water-quality tester, helping the mollusc detect any changes in the water around it, much like how we check water quality for swimming or drinking.
VSAQ-16: What are spermathecae on the body of Pheretima?
In Pheretima (a type of earthworm), spermathecae are like small storage containers where sperm is kept after mating. Imagine four pairs of these containers scattered along the worm’s body, specifically in segments 6 through 9. They store sperm for later use when the earthworm is ready to reproduce.
VSAQ-17: What do you call the perivisceral cavity of an arthropod? Where is it derived from during development?
The perivisceral cavity in arthropods is known as the haemocoel. It’s like a big internal space filled with blood rather than a traditional coelom. This cavity develops from the blastocoel during the embryo’s growth, and it acts as the main body cavity where blood circulates, providing nutrients and removing wastes.
VSAQ-18: What are blood glands in Pheretima?
In Pheretima, or earthworms, blood glands are located in segments 4, 5, and 6. These glands are like tiny factories producing blood cells and haemoglobin, which is crucial for carrying oxygen. These glands ensure that the earthworm’s blood is rich with the necessary components for survival and efficiency.