Diversity in Living Organisms Test - 21

• Toads are amphibians. But they differ from frogs in having dry, warty skin, shorter legs which help them to crawl around rather than hop.  
• Jellyfish are mainly free-swimming marine animals with umbrella-shaped bells and trailing tentacles. Jellyfish belong to the phylum Cnidaria, which is a phylum consisting of invertebrates.
  
• Penguins are a group of aquatic flightless birds. They are oviparous. They do not nurse their young ones with milk like mammals.

Birds are members of class Aves. They are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds use their strong breast muscles to flap their wings and give them the thrust to move through the air and fly.
So, the correct answer is option D.

Enterobiasis is pin-worm infection which is a human parasitic disease and one of the most common parasitic worm infections.
So, the correct answer is 'Pin'.

Whales are aquatic mammals. Like other mammals, they have mammary glands that secrete milk to feed their young ones.

An arthropod is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed legs. Arthropods form the phylum Arthropoda and include insects that have wings.
Birds are not invertebrates. Annelids do not have wings. Protists are unicellular organisms. Protists are not animals.
So, the correct answer is option B.

Arthropoda is the largest phylum of animals within which, the class Insecta has the maximum number of species. Insects make up around 75% of the phylum Arthropoda. They occupy a variety of habitats and can crawl, fly, jump or swim. Most of them lay eggs in protected places and only a few species show parental care. They sometimes protect themselves with venom and use camouflage to protect themselves from their predators or to attack their prey.

Out of the options given, birds lack teeth. Due to the absence of teeth, their digestive system is well adapted to make up for their absence. Their digestive consists of the crop which is involved in the storage of food and gizzard that contains stones that help in grinding food as no teeth as present to do so. 

Correct option - C

• Amphibians spend their lives in water and on land. There are more than 4,000 different kinds of amphibians. Members of this animal class are frogs, toads, salamanders, newts, and caecilians or blindworms.
• Before amphibians reach adulthood, they first experience a larval stage, where they breathe primarily through their gills. When they get older, they start to breathe through their lungs, which allows them to live on land. Hence, it is necessary for amphibians to live in both land and water.
  

So, the correct answer is 'Amphibian'.