Tag: locomotion and reproduction

Questions Related to locomotion and reproduction

The movement of the flagellum is regulated by 

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

  1. Plasma membrane

  2. Nucleus

  3. Basal body

  4. Ribosomes

Show answer
Correct Option: A
Explanation:

Bacterial flagella are helically shaped structures containing the protein flagellin. The base of the flagellum (the hook) near the cell surface is attached to the basal body enclosed in the cell envelope. The flagellum rotates in a clockwise or counterclockwise direction, in a motion similar to that of a propeller. This movement is regultaed by plasma membrane.

Thus, the correct answer is 'Plasma membrane.'

Find the correct statement in relation to flagella: 

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

  1. Flagella are longer and less in number than cilia.

  2. Flagella usually beat independently.

  3. Arms of subfibril A are made of Nexin protein.

  4. A-B linker is made of dyenin protein.

Show answer
Correct Option: A
Explanation:

Flagella are long, numerous hairlike projections from the plasma membrane. Flagella are longer and less in number than cilia. In multicellular organisms, cilia and flagella are the major means of locomotion in prokaryotic cells, both cilia and flagella are composed of microtubles.

So, the correct option is 'Flagella are longer and more in number than cilia'.

The movement of cilia and flagella is due to the presence of _________.

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

  1. radial spokes

  2. central sheath

  3. singlet micritubules

  4. dyneins

Show answer
Correct Option: D
Explanation:

Groups of dynein molecules responsible for movement in opposite directions are probably activated and inactivated in a coordinated fashion so that the cilia or flagella can move back and forth.

Pili, Fimbriae and flagella

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

  1. Play a role in motility in bacteria

  2. Are surface structures of bacteria

  3. Play a role in motility in eukaryotic cells

  4. Are elongated tubular structures made of a special phospholipid

Show answer
Correct Option: B
Explanation:

Pili, Fimbriae and flagella are structures that are found on the cell wall of the bacteria. These are structures that are made out of cellular components like proteins, for example, Pilli is made up of the protein pilin and flagella is made up of the protein flagellin.

Flagella are longer than both pili and fimbriae. These are a surface structure of the bacteria.
So, the correct option is 'Are surface structures of bacteria'

Arrangement of microtubules in a flagellum and a centriole is _______ and ________ respectively.

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

  1. $9 + 2$ and $9 + 1$

  2. $9 + 1$ and $9 + 0$

  3. $9 + 0$ and $9 + 2$

  4. $9 + 2$ and $9 + 0$

Show answer
Correct Option: D
Explanation:
A centriole possesses a whorl of nine peripheral fibrils. Fibrils are absent in the centre. The arrangement is, therefore, called $9 + 0$. Flagellum contains an axoneme of a peripheral doublet fibrils and $2$ central singlet fibrils. This arrangement is called $9 + 2$ or $11$ stranded.
So, the correct answer is '9+2 and 9+0'.

Filaments present in flagella/cilia are

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

  1. Microfibrils

  2. Microtubules

  3. Microfilaments

  4. Microvilli

Show answer
Correct Option: B
Explanation:
  • Cilia and flagella are small hair-like projections from the cell and are composed of microtubules which are arranged with their positive end at the outer tip of the axoneme.
  • A microtubule is a tubular linear polymer of tubulin protein which is a part of the cytoskeleton that helps to provide structure and shape to the cytoplasm of a eukaryotic cell.
  • So, the correct answer is 'Microtubules'.

The variation in pattern of 9+2 in cilium or flagellum is shown by 

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

  1. Flatworm

  2. Eel

  3. Sporozoan protozoan

  4. All of the above

Show answer
Correct Option: D
Explanation:

The 9+2 arrangement of fibrils is characteristics of eukaryotes being comprised of 9 peripheral doublet and 2 central singlet fibrils. Although the 9 + 2 pattern is the fundamental pattern of virtually all cilia and flagella, the axonemes of certain sporozoan protozoans and some insect sperm show some interesting variations. The spermatozoids of flatworms are also atypical. The eel sperm shows 9+0 arrangement. These atypical cilia and flagella, which are all motile, show that the central pair of singlet microtubules is not necessary for axonemal beating and that fewer than nine outer doublets can sustain motility, but at a lower frequency.

Which of the following statement regarding cilia is not correct?

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

  1. Cilia contain an outer ring of nine doublet microtubles surrounding two single microtubles.

  2. Cilia is an organelle found in prokaryotes.

  3. Cilia are short, hair-like cellular appendages.

  4. Microtubules of cilia are composed of tubulin.

Show answer
Correct Option: B
Explanation:

Cilia are short, hair like appendages extending from the surface a living cell. Cilia are found exclusively in the prokaryotes.