Question:

Animals possess nerve networks or nervous systems to respond to their environment. But the single called Amoeba does not possesses any nerve cell, so, how it come to know whether a particle it encounters is a grain of sand and not its dinner ?

Updated On: Jul 27, 2022
  • By chemotaxis
  • By skin
  • By hormones
  • All of these
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is A

Solution and Explanation

Although the Ameba has no sense organs, it responds to chemical stimuli. It makes this determination by chemotaxis, a kind of chemical sense. This is the same response mechanism that our white blood use when they encounter and phagocyrize a pathogen.
Was this answer helpful?
0
0

Questions Asked in AIIMS exam

View More Questions

Concepts Used:

Kingdom Protista

Biological Classification: Kingdom Protista

Protista is the kingdom that includes single-celled eukaryotes. They are typically found in the water. In the aquatic ecosystem, algae, for example, are the primary producers. They are eukaryotic creatures with only one cell. They have a true core that is separated from the rest of the cell by the nuclear membrane. They can move by cilia and flagella; they can breathe both aerobically and anaerobically, and they can reproduce both sexually and asexually.

Characteristics of Kingdom Protista:

  1. They are eukaryotic, which means they have a nucleus.
  2. Most have mitochondria.
  3. They can be parasites.
  4. They all prefer aquatic or moist environments.

Read More: Biological Classification

Classification of Protista

They are divided into Chrysophytes, Dinoflagellates, Euglenoids, Slime molds, and Protozoans.

Chrysophytes

This category includes diatoms and golden algae. They are found in both freshwater and marine settings. In nature, they are photosynthetic. Their cell walls are made of silica. They are the most important producers in the oceans. Most of them are unicellular flagellates. They are amoeboids.

Dinoflagellates

They are photosynthetic organisms that live in the sea. They can be yellow, green, brown, blue, or red, depending on the cell pigment. The outside surface of their cell walls is covered in cellulose plates, making them rigid.

Euglenoids

They are frequently found in stagnant water and are freshwater creatures. They make use of their photosynthetic nature when exposed to sunshine. They eat smaller organisms when they are deprived of sunshine.

Slime Moulds

They feed on rotting twigs, leaves, and organic waste and are saprophytic. Even in the face of adversity, they can live for a long time.

Protozoans

All protozoans are parasite-eating predators. Amoeboid protozoans, Flagellated protozoans, Ciliated protozoans, and Sporozoans are the four types of protozoans.