Tag: zoology

Questions Related to zoology

Which of the following statements regarding cilia is not correct?

zoology locomotion and reproduction flagella other cell components single membrane bound organelles

  1. Microtubules of cilia are composed of tubulin.

  2. Cilia contain an outer ring of nine double microtubules surrounding two single microtubules.

  3. The organised beating of cilia is controlled by fluxes of Ca$^{2+}$ across the membrane.

  4. Cilia are hair-like cellular appendages.

Show answer
Correct Option: C
Explanation:

The shaft of cilia and flagella consists of an external sheath, semi fluid matrix and an axoneme. Axoneme has 9+2 fibrillar arrangement, comprising of nine peripheral doublet microtubule fibrils and two central singlet microtubule fibrils, central sheath, linkers and spokes. Certain flagella possess lateral hairs called flimmer filaments. Such flagella are called tinsel Flagella.

Flagella devoid of flimmers are called smooth or whiplash flagella. The cilia function like an oar. They have a power or effective stroke which pushes the fluid in one direction with a jerk while the cell is pulled in the opposite direction. This movement does not depends on calcium ion flux.

Select the incorrect statement.

zoology locomotion and reproduction flagella other cell components single membrane bound organelles

  1. Flagella are comparatively longer than cilia & responsible for cell movement.

  2. The prokaryotic flagella are functionally different from eukaryotic flagella.

  3. The axoneme of cilia usually has nine peripheral doublets of microtubules.

  4. Centrioles form the basal body of eukaryotic cilia flagella.

Show answer
Correct Option: B
Explanation:

Prokaryotic and eukaryotic flagella are different in the structure but their function is similar as they are used for the locomotion in prokaryotes while in gametes of eukaryotes are also used for movement.

So the correct option is 'The prokaryotic flagella are functionally different from eukaryotic flagella.'

The principal protein of cilia and flagella is

zoology locomotion and reproduction flagella other cell components single membrane bound organelles

  1. Tubulin

  2. Albumin

  3. Globulin

  4. Gliadin

Show answer
Correct Option: A
Explanation:

The cytoskeletal structures are of three types : microtubules (made of tubulin protein), microfilaments (made of actin protein) and intermediate fibres (made of keratin protein). 

Microtubules are basic structures of spindle apparatus, centrioles, basal bodies, cilia and flagella.

In eukaryotic flagella, membrane bound central part is termed as?

zoology locomotion and reproduction flagella other cell components single membrane bound organelles

  1. Shaft

  2. Central sheath

  3. Axonema

  4. Spoke

Show answer
Correct Option: C
Explanation:

Inside cilia and flagella is a microtubule-based cytoskeleton called the axoneme. The axoneme of primary cilia typically has a ring of nine outer microtubule doublets (called a 9+0 axoneme), and the axoneme of a motile cilium has two central microtubules in addition to the nine outer doublets (called a 9+2 axoneme). The axonemal cytoskeleton acts as a scaffolding for various protein complexes and provides binding sites for molecular motor proteins such as kinesin II, that help carry proteins up and down the microtubules.


So the correct option is 'Axoneme'.

Read the following statements:
(i) Cilia and flagella work like oars
(ii) Cilia are relatively longer than flagella
(iii) Prokaryotic and eukaryotic flagella are structurally similar
(iv) Cilia and flagella are covered with plasma membrane in eukaryotes
(v) The core of cilia/flagella is called axoneme which has nine pairs of doublets or radially arranged peripheral microtubules and a pair of centrally located microtubules.
How many of the given statements are correct?

zoology locomotion and reproduction flagella other cell components single membrane bound organelles

  1. Three

  2. Two

  3. Four

  4. Five

Show answer
Correct Option: A

Flagella are composed of

zoology locomotion and reproduction flagella other cell components single membrane bound organelles

  1. $9$ pairs of mictotubules syrrounding a central pair of microtubules

  2. $9$ pairs of microtubules surrounding a single central microtubule

  3. $9$ microtubules surrounding a central pair of microtubules

  4. None of these

Show answer
Correct Option: A

Read the following statements and state true (T) or false (F) regarding cilia and flagella of eukaryotic cells.
Both the cilium and flagellum emerge from basal bodies.

zoology locomotion and reproduction flagella other cell components single membrane bound organelles

  1. True

  2. False

Show answer
Correct Option: A
Explanation:
  • A basal body can be defined as a protein structure which is found at the base of a eukaryotic undulipodium (cilia or flagella).
  • It acts as a nucleation site for the growth of the axoneme microtubules.
  • The basal bodies undergo a transition to form the cytoskeletal structure present in cilia or flagella called the axoneme.
  • So the correct answer is 'True'.

Which of the following type of movement are seen in human body?
A. Amoeboid     B. Ciliary     C. Flagellar     D. Muscular

zoology locomotion and reproduction flagella other cell components single membrane bound organelles

  1. A, b and c

  2. A, b and d

  3. A, c and d

  4. A, b, c and d

Show answer
Correct Option: B
Explanation:

A human body has a different type of cells which shows different types of movements at different places in the body.

These movements include:-
  • Amoeboid movement, for example, white blood cells show this type of movement. 
  • Ciliary in the respiratory tract, 
  • Muscular is the most common type of movement for both voluntary and involuntary movements.
So the correct answer is 'Amoeboid, Ciliary and muscular'.

Read the following statements and state true (T) or false (F) regarding cilia and flagella of eukaryotic cells.
A cilium or a flagellum is not covered with plasma membrane.

zoology locomotion and reproduction flagella other cell components single membrane bound organelles

  1. True

  2. False

Show answer
Correct Option: B
Explanation:
  • Cilia or flagella can be defined as projections from the cell which are made up of microtubules.
  • It consists of a central core (two microtubules) that is surrounded by an outer ring of nine pairs of microtubules (9+2 arrangement).
  • The outer ring of microtubules is surrounded by an extension of the cell membrane.
So the correct answer is 'False'.

Read the following statements and state true (T) or false (F) regarding cilia and flagella of eukaryotic cells.
The axoneme usually has nine pairs of triplets of radially arranged peripheral microtubules.

zoology locomotion and reproduction flagella other cell components single membrane bound organelles

  1. True

  2. False

Show answer
Correct Option: B
Explanation:
  • Axoneme refers to the cytoskeletal structure which forms the central strand of a cilium or a flagellum.
  • It is composed of an array of microtubules which typically consists of nine pairs of doublet around two single central ones.
So the correct answer is 'False'.