Short & Long Question Answers with Solution: Animal Kingdom - NEET PDF Download

Short and Long Answer Type Questions

Q.2. Mention the role of the radula in Molluscs.
Ans: The radula in Molluscs serves to scrape and scratch food, aiding in its consumption. Additionally, it helps create depressions in rocks, which often serve as the habitat for Molluscs.

Q3. All vertebrates are termed chordates, but all chordates are not vertebrates. Justify the statement.
Ans:  The phylum Chordata has two special features, the presence of Notochord and paired pharyngeal gill slits. However, most adults replace the vertebrate Notochord in the embryo in the subfile with the columns of the bony vertebrae. It is, therefore, classified as, “All vertebrates are chordates, but not all chordates are vertebrates.”

Q.4. What do you understand by metagenesis? Give an example.
Ans: Metagenesis is the process where asexual reproduction in one generation is succeeded by sexual reproduction in the next, as seen in Coelenterates, for example.

Q5. What are the unique modifications observed in birds that help them fly?
Ans: Birds are a species that are characterised by the presence of feathers. The special modification observed in birds that help them to fly is that their forelimbs are converted into wings, which help them to fly, while their hind limbs have scales.
They have pneumatic, also known as hollow bones, that lighten the skeleton and do not contain a urinary bladder which causes net body weight loss and facilitates them to fly more freely. They also contain a streamlined body which provides less resistance and enables longer flight.

Q6. Can the number of eggs or young ones produced by an oviparous and viviparous mother be equal? Why?
Ans: No, the number of young ones which an oviparous and viviparous mother produces are not equal. The number of young ones produced by oviparous mothers is more than that of viviparous animals. Because in most oviparous animals, Fertilisation takes place outside the uterus, whereas in viviparous animals, Fertilisation and development of the zygote take place inside the uterus, which results in the successful incubation of young animals.
When eggs are present outside in nature, there is a high risk of eggs being consumed by predators. Therefore, to sustain the progeny, more eggs are required.

Q7. What is bioluminescence? Give an example.
Ans: Bioluminescence is the term for the generation and release of light by living organisms. It is commonly observed in marine creatures, certain fungi, and a select group of land-dwelling invertebrates. Jellyfish and fireflies are notable examples of organisms that display bioluminescence.

Q.8. Give examples of warm and cold-blooded animals?
Ans: All birds and mammals are examples of warm-blooded animals.
All amphibians -frogs, toads, and salamanders, aquatic animals, such as alligators, crocodiles, sharks,  lizards, fish, snakes, turtles, tortoises, and some insects such as the dragonflies and bees are all examples of cold-blooded animals.

Q9. Which of the following sets of animals defined below belongs to a single taxonomic group?
(a) Cuttlefish, Jellyfish, Silverfish, Dogfish, Starfish
(b) Bat, Pigeon, Butterfly
(c) Monkey, Chimpanzee, Man
(d) Silkworm, Tapeworm, Earthworm
Ans: (c)
Explanation: Monkeys, chimpanzees and men have many similar characteristics and are placed in one common group.

Q10. Distinguish between the following terms-  

• Closed circulatory system and Open circulatory system. 
• Oviparous and viviparous characteristics 
• Direct development and Indirect development

Ans: 
a) In the open circulatory system, the blood is pumped out of the heart, flows freely through cavities and is not confined to blood vessels. It is mainly found in vertebrates. . In contrast, blood is circulated throughout the body with the help of a series of vessels in the closed circulatory system. It is present in vertebrates and echinoderms.
b) Laying fertilised and unfertilised eggs are called oviparous animals, whereas giving birth to young ones is classified under viviparous animals.
c) In direct development, the larval stage is absent, and there is an incomplete development of the organism. In contrast, the larval stage is present in the organism’s development, which does not resemble the adult, called indirect development.

Q11. What are triploblastic animals?
Ans: Triploblastic animals are those with three germ layers, namely the ectoderm, mesoderm, and endoderm. This category encompasses a wide range of multicellular creatures, such as Molluscs, worms, arthropods, Echinodermata, and vertebrates.

Q12. The body cavity is the cavity between the body and gut walls. In some animals, the body cavity is absent, while in some, it is present. To define the terms.
(a) Acoelomate and
(b) Pseudocoelomate.
(c) Coelomate 
Ans:
(i) Acoelomate: Acoelomates are animals in which the body cavity is absent. E.g., Porifers, Coelenterates, Ctenophores and Platyhelminthes.

(ii) Pseudocoelomate: The mesoderm is not lined in some animals. Instead, the mesoderm is present as scattered pouches between the ectoderm and endoderm. Here the body cavity is directly connected to the archenteron. Such a body cavity is known as pseudocolour, and pseudocoelomates are the animals possessing the body cavity examples are Aschelminthes, also known as Ascaris.

(iii) Coelomate: In coelomate animals, the coelom is the body cavity lined by mesoderm on both sides. Animals possessing coelom are called coelomates, the cavity between the alimentary canal and body wall enclosed by mesoderm on both sides. E.g., Annelids, Arthropods, Molluscs, Echinoderms, Hemichordates and Chordates.

Depending upon its origin, true coelom or coelom is of two types:

(a) Schizocoelous: The coelom is formed by the splitting of mesoderm. E.g., Annelida, Arthropoda and Mollusca.
Note: The cavity filled with blood is called haemocoel. It is found in Arthropods (cockroaches) and Molluscs (Pila).
(b) Enterocoelom: The coelom develops as an outgrowth of the enteron or embryonic gut. E.g.: Deuterostomia (Echinodermata and Chordata). Echinodermata is an enterocoelomate invertebrate.

Q13. Endoparasites are found inside the host body. Mention the special structure these possess, which enables them to survive in those conditions.
Ans: Because of their extreme specialisation, the life cycles of endoparasites are more complex. Their morphological and anatomical features are mostly simplified while emphasising their reproductive potential.
Following their lifestyle, parasites evolve special adaptations, which include:

• Loss or absence of unnecessary sense organs.
• Absence of digestive system.
• A high reproducing capacity.
• Presence of suckers, also called adhesive organs, that help cling onto the host.

Q14. What is the relationship between the germinal layers and the body cavity formation in the case of coelomates, acoelomates and pseudocoelomates?
Ans: Germinal layers are those formed during the process of gastrulation. The outer layer of the germ is called the ectoderm, the middle one is the endoderm, and the innermost is the endoderm. Coelomates are organisms that possess coeloms. The coelom is the body cavity which is lined by the mesodermal layer. Annelida, Mollusca, arthropods, etc., are the most common examples of coelomates. The organisms with absent or no body cavities are called acoelomates. One of the most common examples of acoelomate is Platyhelminthes. Some of these organisms do not have a mesoderm lining. Instead, it will be in the form of a scattered pouch between the ectoderm and endoderm layers. Such a body cavity is called pseudocode, and animals possessing pseudocolour are called pseudocoelomates. E.g., Ascaris. 

Q15. What are the significant features that you find in parasitic Platyhelminthes?
Ans: 
The most significant features of the parasitic Platyhelminthes are:

1. They are free-living and parasitic.
2. They contain an organ level of organisation and are mostly hermaphrodites.
3. Their body wall is three layers, with the epidermis being the outer covering made up of ciliate and covered with cuticles.
4. The digestive tract is incomplete or absent
5. There is the presence of well-defined excretory structures, such as flame cells.
6. Presence of anti-toxins and a thick tegument resistant to the host’s digestive enzymes. 
7. They are classified into anaerobic respiration, which means they can survive without air. No special respiratory structure was observed.
8. Their front body is divided into suckers, hooks, eyespots and auricles that help them to attach themselves to the hosts.
9. A highly developed reproductive system.