Biology · General Awareness

Aquatic and Marine Biology

1,834 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 physics forces and matter pressure in fluids pressure in liquids introduction to pressure

If a sweet water fish enters a sea, the fish will

  1. swell

  2. be squeezed

  3. remain as it is

  4. suffer none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Liquid pressure is given by =$\rho \times g \times h$

The water from river has a lower density than the sea water. So, at equal depth, sweet water or river water exerts less pressure than sea water. Body of a sweet water fish is habituated with this lower pressure of river water. Naturally, when the fish will enter the sea, it will suffer greater pressure due to increase in density and hence the body of the fish will be squeezed slightly.

Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure

If a sea fish enters a river, the fish will

  1. swell

  2. be squeezed

  3. remain as it is

  4. suffer none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Density of sea water is more than that of river water. So, at same depth, sea water exerts greater pressure. And, the body of the sea fish is habituated with the high pressure from outside. Now, as the same fish enters the river, water density being low, will suffer less pressure from outside. As a result, the body of the fish will swell out slightly.

Multiple choice zoology animal diversity - ii (phylum: chordata) amphibia and reptilia amphibia classifications of chordata

A non-poisonous snake is______________.

  1. Viper

  2. Python

  3. Bungarus

  4. Sea snake
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Vipers are a family of venomous snakes, the Viperidae. All have long, hinged fangs that dig deep into their prey and inject venom. 
  • Sea snakes are venomous. They are typically found in Indo-Australian and Southeast Asian waters.  
  • Bungarus is a genus of venomous elapid snakes, the kraits found in South and Southeast Asia.  
  • Pythons are a family of non-venomous snakes, the Pythonidae found in Africa and Asia. 
  • so the correct answer is option B.
Multiple choice zoology animal diversity - ii (phylum: chordata) amphibia and reptilia amphibia classifications of chordata

Which of the following is not a true amphibian?

  1. Tortoise

  2. Frog

  3. Salamander

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

Tortoises are considered as reptiles and not amphibians because of the following characteristics:

  • They are vertebrates that is they have a backbone.
  • They are covered in scales.
  • They breathe through lungs.
  • They lay eggs.
  • And they are cold blooded which means they cannot regulate their body temperature.
And all these characteristics are shown by the organisms which fall under the category of reptiles and not amphibians. 

Multiple choice zoology animal diversity - ii (phylum: chordata) amphibia and reptilia amphibia classifications of chordata

Which of the following statement is true for Ichthyophis?

  1. It is limbless reptile, who lives in water

  2. It is limbless amphibian, who lives in water

  3. It is limbed, lives on land

  4. It is limbless animal and amphibious in nature
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Ichthyophis is a genus of caecilians (a group of limbless, serpentine amphibians).
  • They are found in moisturized or wet tropical habitats.
  • So, the correct answer is 'It is a limbless amphibian, who lives in water'.
Multiple choice zoology animal diversity - ii (phylum: chordata) amphibia and reptilia amphibia classifications of chordata

An aquatic animal that lays eggs only on land is

  1. Fish

  2. Frog

  3. Sharks

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

Turtles are characterized by a special bony or cartilaginous shell developed from their ribs and acting as a shield. Before the turtle lay their eggs, nearly all turtles prepare a nest on land. During the last weeks of gestation, the pregnant female spends less time in the water and more time on land, smelling and scratching at the ground in search of the perfect place to lay her eggs.

So, the correct answer is 'Turtles'.

Multiple choice evs i love gujarat flora and fauna in forest ecosystem threatened species need of conservation

Fauna that lives in ice is called as 

  1. Megafauna

  2. Microfauna

  3. Cryofauna

  4. Epifauna
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The animal life which is found in a particular region at a particular period of time is known as fauna. This includes the various different types of animals found in that area. On the basis of the habitats, size and the environments in which the animals are found, the animals are classified into various different types of fauna as megafauna, cryofauna, microfauna, etc. The animals or the organisms which can live in or close to ice are known as the cryofauna. 

Thus, the correct answer is option C. 

Multiple choice biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

Many freshwater organisms cannot live for long in seawater because the surrounding water will be ______ to body cells and ______ may occur.

  1. Hyper tonic, Exosmosis

  2. Hyper tonic, Endosmosis

  3. Hypo tonic, Exosmosis

  4. Hypo tonic, Endosmosis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the sea water , the surrounding water is salty and hence hypertonic to the body cells, Thus, water will move from its higher concentration to ts lower concentration leading to exosmosis. Therefore, many fresh-water animals cannot live for long in sea water and vice versa. 

Multiple choice evs insectivorous plants meaning of an ecosystem food chain and food web components of environment and their interdependencies

The concentration of polychlorinated biphenyls (PCB, an organochloride contaminant) in many fish populations has been declining, since a ban on their production was instituted in the late 1970s. PCBs remain a potential problem, however, because they are lipophilic and are known to biomagnify. Based on this knowledge, 

What type of fish expected to be safest for human consumption?

  1. Piscivorous fish species (i.e., which eat other fish)

  2. Benthivorous fish species (i.e., which eat invertebrates on the lake bottom)

  3. Small (young) fish

  4. Fish species with high fat content
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Heavy metals and persistent pesticides (e.g., organochlorine of chlorinated hydrocabons like DDT) pass into food chain and increase in amount per unit weight of organisms with the rise in trophic level due to their accumulation in fat, This phenomenon is called biomagnification. Therefore, lower the trophic level of fish (such as small fish), lesser will be the biomagnification and hence safer it will be for consumption.

Multiple choice evs sources of water the lithosphere and the hydrosphere first aid safety and first aid

Which one of the following fish is being illegally introduced for aquaculture purposes and is posing a threat to the indigenous catfishes of Indian rivers?

  1. Clarias gariepinus

  2. Nile perch

  3. Climbing perch

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

Clarias gariepinus, the African catfish has been illegally introduced for aquaculture purposes and is posing a threat to the indigenous catfishes of Indian rivers.

Multiple choice zoology our health harmful microorganism for humans microbes and diseases categories of diseases

Toxins (saxitoxins) secreted by some dinoflagellates enter the body of human beings through food chain and result in

  1. Madness

  2. Paralysis

  3. Syphilis

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

Genus Alexandreum of dinoflagellates secretes neurotoxin saxitoxins which are the causative agents of paralytic shellfish poisoning (PSP). Molluscs such as mussels and clams feed on a large number of dinoflagellates, human consumption of those molluscs causes paralysis. 

Madness is a characteristic symptom of rabies which is caused by RNA virus “rabies virus” and is mostly spread through the bite of an infected dog. 
Syphilis is a sexually transmitted disease, caused by gram negative spirochete, Treponema pallidum. 
Plague is caused by gram negative rod shaped bacteria. Yersinia pestis and is characterised by flu-like symptoms. It is transmitted by bites from infected fleas. So, the correct answer is option B.

Multiple choice

Which of the following is a type of fish that is commonly found in estuaries?

  1. Flounder

  2. Salmon

  3. Trout

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

Flounder is a type of fish that is commonly found in estuaries.