Biology · General Awareness

Aquatic and Marine Biology

1,905 Questions

This hub covers key concepts in aquatic and marine biology, including fish anatomy, marine animal behavior, and commercial fisheries. These topics are essential for general science sections in various competitive exams. Use these resources to test your knowledge of diverse aquatic ecosystems.

Marine animal adaptationsCommercial fisheriesFish anatomyAquatic ecosystems

Aquatic and Marine Biology Questions

Multiple choice biology respiration in living organisms breathing underwater respiration in other organisms respiration in organism

Which organ is used by fishes for their respiration?

  1. Gills

  2. Skin

  3. Fin

  4. Nostril
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Gills are tissues which consist of cloth and fabric structures called filaments. These filaments have many functions including the transfer of ions and water, as well as the exchange of oxygen, carbon dioxide, acids and ammonia.

Multiple choice biology respiration in living organisms breathing underwater respiration in other organisms respiration in organism

Which of the following has no blood but respires? 

  1. Earthworm

  2. Hydra

  3. Cockroach

  4. Fish
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In animals, three main types of respiratory systems exist: respiration through the skin, respiration through the gills or respiration through internal air structures. Respiration through the skin, as in the hydra, involves the passing of molecules into and out of the body via diffusion. Aquatic animals use gills, which are structures composed of tissues and blood vessels that extend from the body, for their respiration needs. Most terrestrial animals use internal air structures, such as lungs or tracheae, to respire. 

Therefore, the correct answer is option B.

Multiple choice biology respiration in living organisms breathing underwater respiration in other organisms respiration in organism

A freshwater fish must continuously

  1. Acquire water and get rid of salt

  2. Get rid of both water and salt

  3. Acquire both water and salt

  4. Get rid of water and acquire salt
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Freshwater fish lives in rivers and lakes where the salinity levels are less than 0.05%. The freshwater species differ physiologically from salt water fish in that their gills are modified to diffuse dissolved gasses while retaining the salts present in the body fluids. Further, their scales reduce water diffusion through the skin and also have well developed kidneys that can reclaim salts from body fluids before excretion. Through this process, they get rid of water and acquire salt.

Multiple choice biology respiration in living organisms breathing underwater respiration in other organisms respiration in organism

A marine bony fish must continuously

  1. Acquire water and get rid of salt

  2. Get rid of both water and salt

  3. Get rid of water and acquire salt

  4. Acquire both water and salt
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water naturally seeks a chemical balance, or equilibrium. That means water flows from areas of higher water concentration to areas of lower water concentration to equalize the system. Water concentration inside a fish is higher than in the ocean itself because the ocean is so salty. As a result, most saltwater fish constantly lose water through their gills and skin. Because the fish is losing water, it must drink a lot to stay hydrated-but salty seawater is the only water around. To get rid of excess salt, the fish's kidneys pump lots of salt into its urine.

Multiple choice evs water in our life where do we get water from? why conserve water uses of water

Animal that can change its colour is 

  1. Planaria

  2. Octopus

  3. Leech

  4. Hydra
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Squids, octopuses, and cuttlefishes are among the few animals in the world that can change the colour of their skin in the blink of an eye.
  •  These cephalopods a group of molluscs with arms attached to their heads can change their skin tone to match their surroundings, rendering them nearly invisible, or alternatively give themselves a pattern that makes them stand out. 
  • Hence, Animal that can change its colour is Octopus.
  • So, the correct answer is 'Octopus'.
Multiple choice zoology biodiversity and its classifications vertebrates characteristics of vertebrates classification of organisms

Which of the following is a catfish?

  1. Labeo rohita

  2. Catla catla

  3. Cirrhina mrigala

  4. Wallago attu
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A. Labeo rohita, known as the carp fish, is found in sluggish and clear streams.
B. Catla catla, known as the major carp, is a freshwater fish.
C. Cirrhina mrigala is a ray finned fish in the genus Cirrhina.
D. Wallago attu is a freshwater catfish in the family Siluridae.
So, the correct answer is 'Wallago attu'.
Multiple choice zoology biodiversity and its classifications vertebrates characteristics of vertebrates classification of organisms

Pectoral fins are enlarged in

  1. Hippocampus

  2. Exocoetus

  3. Coccosteus

  4. Scoliodon
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
A. Hippocampus, commonly known as sea horse, is a small marine fish.
B. Exocoetus is known as flying fish. It has a powerful tail by which it is able to make large jumps over the surface of water. It has enlarged pectoral fins.
C. Coccosteus is a genus of extinct placoderm fishes.
D. Scoliodon is known as Dog fish. It has powerful sense of smell like that of a dog.
So, the correct answer is 'Exocoetus'.
Multiple choice zoology biodiversity and its classifications vertebrates characteristics of vertebrates classification of organisms

Heart pumps only impure blood in case of

  1. Sharks

  2. Whale

  3. Lizard

  4. Frog
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The heart pumps only impure blood in sharks. Sharks have a two-chambered heart which is an S-shaped tube. It has an atrium and ventricle. The blood is pumped by the heart through the afferent branchial arteries to capillaries in the gills, where the blood is oxygenated). 
  • The blood then flows through efferent branchial arteries, through the tissues of the body, and back to the heart in veins. Sharks have low blood pressures; the walls of the pericardium are rigid, creating suction within the pericardium to maintain the flow of blood. To circulate blood throughout their bodies, many sharks must swim continuously. 
  • The blood flow is similar to humans because blood is pumped by the heart to the rest of the body by arteries and returned to the heart by veins. 
  • A difference is that humans have 4-chambered hearts while sharks only have two chambers.
Multiple choice zoology biodiversity and its classifications vertebrates characteristics of vertebrates classification of organisms

Which one of the following is an example of viviparous animal?

  1. Amphibians

  2. Bony fish

  3. Fish

  4. Shark
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Viviparous sharks give birth to live young. The number of pups in a litter ranges from 2-20 or more. For example, the Bull sharks, Whitetip reef shark, Lemon shark, Blue shark, Mako, Porbeagle, Salmon shark, the Silvertip shark, and Hammerheads.

Amphibians are oviparous because the young hatch after the egg is laid.
Bony fish and fish are oviparous in nature.

Multiple choice evolutionary changes in heart transportation - the circulatory system

Which of the following has a 3 chambered heart?

  1. Salamander

  2. Fish

  3. Crocodile

  4. Dolphin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vertebrates have evolved a muscular heart to pump blood to body parts. Fishes have two chambered heart. Birds and mammals have four chambered heart, having two auricles and two ventricles. Reptiles, except crocodile, have three chambered heart. Crocodiles have four chambered heart. Thus Dolphin being a mammal has four chambered heart. Salamander being an amphibian has a three chambered heart.

Multiple choice evolutionary changes in heart transportation - the circulatory system

Four chambered heart is present in 

  1. Frog

  2. Crocodile

  3. Shark

  4. Lizard
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Among reptiles the heart is 3- chambered but the crocodile is an exception where the heart is 4- chambered but not completely divided. The left and right aorta are connected by a hole called the foramen of Panizza. The frog heart has 3 chambers: two atria and a single ventricle. Sharks have a two-chambered heart, with an atrium (also called the auricle) and a ventricle. Lizard also has three chambered heart. 
Thus, the correct answer is option B.
Multiple choice evolutionary changes in heart transportation - the circulatory system

The number of chambers in the heart of fish are

  1. One

  2. Two

  3. Three

  4. Four
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Fish heart is made up of 2 chambers- one auricle and one ventricle, The auricle receives the deoxygenated blood which then passes to ventricle and then to whole of the body. 
Therefore, the correct answer is option B.