Animal Kingdom MCQ Quiz - Objective Question with Answer for Animal Kingdom - Download Free PDF

The correct answer is a poikilotherm

Explanation:

• Animals are often classified based on their ability to regulate body temperature. This classification determines whether their body temperature remains constant or fluctuates with environmental conditions.
• Poikilotherms are animals whose body temperature varies with the temperature of their surroundings. Unlike homeotherms, they do not maintain a constant internal body temperature. Organisms like amphibians, reptiles, and fish are common examples of poikilotherms as they rely on external heat sources to regulate their body temperature.
• Homoeotherm: These are animals that maintain a constant internal body temperature, regardless of environmental conditions. Examples include mammals and birds. 
• Ectotherm: While ectotherms also rely on external sources of heat for body temperature regulation, this term primarily refers to the source of heat rather than the fluctuation in body temperature.
• Endotherm: These are animals that generate internal heat through metabolic processes to maintain a stable body temperature. Examples include humans, cats, and dogs.

The correct answer is Cloaca

Explanation:

• During embryonic development in frogs, a structure called the blastopore forms. The blastopore is an opening that connects the archenteron (primitive gut) to the external environment.
• In deuterostomes like frogs, the blastopore develops into the cloaca, which is a common cavity for the intestinal, urinary, and reproductive tracts.

Other Options:

• Mouth: The blastopore does not develop into the mouth in frogs. Instead, the mouth forms separately from the stomodeum during embryonic development.
• Nasal Pore: Nasal openings develop independently to connect the nasal cavity to the external environment.
• Gonopore: Gonopores are specific openings for gamete release in certain organisms, but in frogs, reproductive openings are part of the cloaca.

The correct answer is 2nd and 3rd thoracic segments

Explanation:

• Insects are members of the class Insecta, characterized by their segmented bodies, jointed appendages, and exoskeleton.
• The body of an insect is divided into three main segments: head, thorax, and abdomen.
• The thorax is the central segment of the body, and it plays a crucial role in locomotion as it supports both wings and legs in flying insects.
• Flying insects typically bear wings only on the 2nd and 3rd thoracic segments (mesothorax and metathorax).
• The mesothorax typically supports the forewings, while the metathorax supports the hindwings.
• These wings are crucial for flying and are supported by strong muscles within these thoracic segments.
• Examples include butterflies, bees, and dragonflies, where the wings are attached to the 2nd and 3rd thoracic segments.

The correct answer is Crocodiles

Explanation:

• The foramen of Panizza is a unique anatomical feature found in the heart of crocodilians, a group that includes crocodiles, alligators, caimans, and gharials.
• This structure is a small opening or channel that connects the left and right aortae near the base of the heart.
• It plays a crucial role in regulating blood flow and allows crocodiles to efficiently manage oxygenated and deoxygenated blood circulation, especially during diving or when submerged underwater.

Fig: Crocodile heart

Key Points about the Foramen of Panizza:

• The foramen of Panizza is not found in other groups of animals, making it a distinctive feature of crocodilian anatomy.
• This structure allows for the mixing or bypassing of oxygenated and deoxygenated blood. During diving, crocodiles can redirect blood flow to prioritize oxygen delivery to essential organs like the brain and heart while reducing blood flow to the lungs.
• Crocodiles are often submerged for extended periods. The foramen of Panizza enables them to conserve oxygen and remain underwater for longer durations.

The correct answer is Longitudinal ciliated groove on the ventral wall of the pharynx of Amphioxus.

Explanation:

• The endostyle is a key anatomical feature found in certain chordates, particularly in primitive species such as Amphioxus (a cephalochordate) and larval forms of tunicates.
• It is a longitudinal ciliated groove located on the ventral wall of the pharynx. Its main function is to produce mucus and aid in trapping food particles during filter feeding.
• In evolutionary terms, the endostyle is considered homologous to the thyroid gland in vertebrates. This evolutionary link is supported by the fact that both structures share a role in iodine metabolism.
• The endostyle secretes mucus, which captures small food particles suspended in water as the organism filters it through its pharyngeal slits.
• The cilia lining the endostyle help in moving the mucus-bound food particles toward the digestive tract for further processing.

Fig: Amphioxus (Internal structure)

Other Options:

• Stylus in the endoderm of the intestine – This is incorrect because the endostyle is not a stylus (rod-like structure) and is not located in the intestine. It is specifically a ciliated groove in the pharynx of chordates.
• Crystalline style in mollusca – This is incorrect because the crystalline style is a structure in mollusks, particularly in bivalves, that aids in digestion by releasing enzymes to break down food. 
• An endodermal derivative in the coelom – Endostyle is of endodermal origin, it is not located in the coelom (body cavity).

The correct answer is Collar cells.

 Key Points

• The body of sponges (poriferans) has several minute pores called ostia through which the water enters into the central cavity, spongocoel.
• The flagellated cells called choanocytes (collar cells) line the spongocoel.
• These cells generate a flow of water and the water current helps in food gathering, respiratory exchange and removal of waste.
• The water finally goes out of the body through a large pore called osculum. (Plural: oscula).
• The body wall of the sponge is composed of two layers: outer pinacoderm and inner choanoderm. In between these two layers, mesenchyme is present with various mesenchymal cells.

Additional Information

• Somatic cells make up the connective tissue, skin, blood, bones and internal organs.
• White blood cells are made in the bone marrow. They are stored in your blood and lymph tissues.
• These sex cells are also called reproductive cells or gametes. Sperm cells are produced in men's testicles and egg cells are produced in women's ovaries

The correct answer is Platyhelminthes.Key Points

• Platyhelminthes are also known as flatworms.
• Flatworms have unsegmented, bilaterally symmetrical, soft bodies, with a triploblastic construction (comprising three layers of cells) and a lacking coelom, skeleton, and anus.
• Example includes Planaria, Liver fluke (Fasciola hepatica), and Tapeworm.

Additional Information

• Cnidaria includes jellyfish, corals, and sea anemones.
  • They have radial symmetry, a single body opening, and stinging cells called cnidocytes.
• Ctenophora includes comb jellies.
  • They have radial symmetry and cilia for movement but also have a complete digestive system.
• Porifera includes sponges.
  • They have asymmetrical or radial symmetry, no true tissues, and filter food through pores in their bodies.

The correct answer is Aschelminthes. Key Points

• ​Roundworms are the popular name for Aschelminthes.
• They are distinguished by having a pseudocoelom.
• They either live freely or are parasites.
• They can be found on plants, animals, humans, and even in freshwater and soil.
• In the human intestine, Ascaris is discovered to exist as an endoparasite.
• The body is triploblastic and bilaterally symmetric.
• The body is long, slender, and not segmented; it tapers out at the end.
• There is no evidence of metameric segmentation.
• Males are often smaller than females since they are dioecious.
• Their bodies are organised on an organ-system level.​

Additional Information

• Platyhelminthes:
  • The flatworms, also known as platyhelminths, are a phylum of soft-bodied, relatively uncomplicated bilaterian invertebrates.
  • They are bilaterally symmetrical, triploblastic, and acoelomate.
  • They could be parasites or free-living beings.
• Ctenophores:
  • Sea waters are home to a phylum of marine invertebrates known as comb jellies, or Ctenophora.
  • They have two embryonic layers, the ectoderm and endoderm, making them diploblastic.
  • They lack a bodily cavity since they are acoelomates.
  • Ctenophores are symmetrical in all directions.
• Mollusca:
  • After Arthropoda, Mollusca is the second-largest phylum of invertebrate animals.
  • Organ system level organization can be seen in them.
  • A cavity exists in their body.
  • The skull, visceral mass, muscular foot, and mantle are the different parts of the body.
  • Tentacles and complex eyes make up the head.
  • The body has a calcareous shell covering it.

Key Points

• Animals belonging to the phylum Chordata are basically characterized by the presence of a notochord, a dorsal hollow nerve cord, and paired pharyngeal gill slits. 
• These are bilaterally symmetrical, triploblastic, coelomate with the organ-system level of organization.
• The notochord is a flexible, rod-shaped structure that is found in the embryonic stage of all chordates. It is located between the digestive tube and the nerve cord and provides support.
• The blood vascular system is present and it is closed type.
• They possess a post-anal tail and a closed circulatory system.
• Common Examples are- Branchiostoma, Ascidia, Lizards.

Explanation:

Phylum Chordata can be divided into 3 sub-phyla -

1. Urochordata - 
   • Notochord is present only in larval tail
   • Examples - Ascidia, Doliolum.
2. Cephalochordata - 
   • Notochord extends from head to tail and is present throughout life.
   • Example - Branchiostoma.
3. Vertebrata - 
   • Notochord is present in the embryonic stage and is replaced by a vertebral column in adult.
   • Examples - Fishes, amphibians, reptiles, birds, mammals.

• Urochordata and Cephalochordata are together known as Protochordata and they are exclusively marine animals.
• Therefore, chordates except the vertebrates will have all the given features, which indicates the Protochordates.

Therefore, the correct answer is Protochordata.

• Limulus does not belong to the Phylum Annelida.
• Annelida are bilaterally symmetrical with an organ-system level of body organization.
• Limulus belong to the Phylum Arthropoda which is the largest phylum of Animalia which includes insects.

Additional Information

• Nereis is a genus of polychaete worms in the family Nereididae.
• It comprises many species, most of which are marine. Nereis possess setae and parapodia for locomotion. 
• The parapodia also help in swimming
• Pheretima also called “Earthworm” belongs to Phylum Annelida
• The earthworm is a reddish-brown terrestrial invertebrate.
• The common Indian earthworms are Pheretima and Lumbricus.
• They inhabit the upper layer of the moist soil.
• During day time, they live in burrows made by boring and swallowing the soil.
• Hirudinaria is an example of Annelida Phylum.
• The annelids are also known as the ringed worms and are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms

Correct answer: 1)

Concept:

• Excess nitrogen in the form of nitrogenous waste is excreted from the body in three forms, that is, ammonia, urea, and uric acid.
• The most toxic nitrogenous waste is ammonia.

Explanation:

a) Ammonotelic

• The organisms that excrete ammonia as nitrogenous waste are known as ammonotelic organisms.
• Ammonia is highly toxic.
• It is highly soluble in water, and therefore requires plenty of water for its excretion.
• Example: bony fishes (like Hippocampus) and aquatic amphibians (like Salamandra).

b) Ureotelic

• Humans and other mammals  (like Ornithorhynchus) excrete urea as nitrogenous waste.
• They are known as ureotelic organisms.
• Urea is less toxic and needs less water in comparison to Ammonia.  
• It is can be stored in cells without toxic effects.

c) Uricotelic

• Birds, insects, reptiles, and land snails all excrete uric acid as nitrogenous waste.
• These organisms are known as uricotelic organisms.
• Pavo is the name of the bird, and it is uricotelic in nature, it excretes out waste in the form of a pellet or paste.

• Needs very little water to get rid of uric acid

So, the correct answer is option 1.

Concept:

• The 5-kingdom classification of Whittaker places the organisms under Monera, Protista, Fungi, Plantae and Animalia.
• Kingdom Animalia is further divided into 11 phyla, which are in order of evolution, meaning they are placed from the most primitive to the most advanced.
• The phyla are: 

Porifera ⇒ Coelenterata (Cnidaria) ⇒ Ctenophora ⇒ Platyhelminthes ⇒ Aschelminthes ⇒ Annelida ⇒ Arthropoda ⇒ Mollusca ⇒ Echinodermata ⇒ Hemichordata ⇒ Chordata.

Important Points

• The circulatory system refers to the the blood vascular system, in which blood is circulated through heart and blood vessels.
• Circulatory system is present in all animals that have a true coelom.
• The presence of coelom or body cavity is an important basis of animal classification.
• All phyla from Annelida onwards to Chordata possess a true coelom and hence, also possess circulatory systems.
• Therefore, the phyla possessing circulatory systems are: Annelida, Arthropoda, Mollusca, Echinodermata, Hemichordata and Chordata.

Circulatory systems can of 2 types - 

1. Open - ​
   • The pumped blood from the heart passes through blood vessels and are released into body cavities called sinuses.
   • It is present in Arthropoda, Mollusca, Echinodermata and Hemichordata.
2. Closed - 
   • Here, blood is pumped through a closed network of vessels.
   • It is a better regulated system and hence, more efficient.
   • It is found in Annelida and Chordata.

Hence, the correct answer is Annelida, Arthropoda, Echinodermata, Mollusca.

The correct answer is India.Key Points

• India is the only country in the world to have both tigers and lions in the wild.
• India is home to the Bengal tiger, which is the most common subspecies of tiger found in the country, and the Asiatic lion, which is only found in the Gir Forest National Park in the state of Gujarat.

Additional Information

• Kenya is known for its wildlife, including lions, but does not have tigers in the wild.
• South Africa is home to lions, but tigers are not native to the country.
• China is known for its giant pandas, but tigers and lions are not native to the country.
• It is important to note that while some countries may have tigers and lions in captivity, India is the only country where both species can be found in their natural habitats.

Correct Answer: 2)

Concept:

• Chordates are a group of animals having a notochord, a dorsal hollow nerve cord, and paired pharyngeal gill slits.
• Phylum Chordata is divided into three subphyla: Urochordata or Tunicata, Cephalochordata, and Vertebrata.
• Vertebrates are chordates in which the notochord is replaced by a bony vertebral column. ​

​

Statement I: All vertebrates are chordates, but all chordates are not vertebrates.

This statement is true, in vertebrate notochord is replaced by a vertebral column. The notochord is present in the embryonic stage and the adult stage, it is replaced by a bony vertebral column. So, all vertebrates are chordates, but all chordates are not vertebrates

Statement II: A notochord is replaced by a vertebral column in adult vertebrates.

This statement is true, the notochord is a cartilaginous rod that is found in the embryonic stage in vertebrates, and later, it gets replaced by a bony vertebral column. That is why they are known as vertebrates.

So, the correct answer is 2.

The correct answer is "(R) is the correct explanation for (A)"

Key Points

• The phylum name Platyhelminthes literally means "flatworms."
• Members of this phylum are soft, thin-bodied, leaf or ribbonlike worms, including the familiar planaria of ponds and streams, as well as the flukes and tapeworms parasitic in human and other animal bodies.
• It is a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates.​

Additional Information

• Various Phylums of Animal Kingdom are:
  •  Porifera
  • Coelenterata (Cnidaria)
  • Platyhelminthes
  • Nematoda
  • Annelida
  • Arthropoda
  • Mollusca
  • Echinodermata
  • Hemichordata
  • Chordata