Tag: single membrane bound organelles

Questions Related to single membrane bound organelles

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.

  1. True

  2. False


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'.

What is common between a Eukaryotic and Prokaryotic flagella?

  1. Same structure

  2. Both are used for locomotion

  3. Composed of same proteins

  4. Both are extension of cell membrane


Correct Option: B

ATP powers the movement of cilia and flagella in eukaryotic cell. These ATP molecules are hydrolysed into ADP+Ip in cilia and flagella by the activity

  1. Nexin protein

  2. Dynein protein

  3. Myosin of muscles

  4. Flagellin protein


Correct Option: B
Explanation:

Movement of cilia and flagella in a eukaryotic cell is powered by ATP and these ATP molecules are hydrolysed into ADP+Pi in cilia and flagella by the activation of dynein protein
Nexin protein is found in cilia and flagella and it prevents microtubules from moving
Myosin of muscles- It is found in animals

Flagellin protein is found in flagella and it made up the structure of it.
so correct answer is  ' Dynein protein ' 

The obilique and parallely arranged strips which are responsible for metaboly are present in

  1. Flagella

  2. Paraflagellar body

  3. Cytoplasm

  4. Pellicle


Correct Option: A
Explanation:

The body of euglenoids are covered by a thin pellicle, that has oblique but parallelly arranged stripes. It provides it the flexibility to cause temporary changes in body shape. The pellicle strips slide over one another to help in metabolic. So, the correct option is 'Pellicle'.

Read the following statements and state true (T) or false (F) regarding cilia and flagella of eukaryotic cells.
Cilia are small structures which work like oars, causing the movement of the surrounding fluid.

  1. True

  2. False


Correct Option: A
Explanation:
  • A cilium is an organelle found on eukaryotic cells and are slender, small protuberances that project from the much larger cell body.
  • It works like oars, causing the movement of the surrounding fluid. They are primarily responsible for locomotion, either of the cell itself or of fluids on the cell surface.
  • Hence Cilia are small structures which work like oars, causing the movement of the surrounding fluid is a True statement.
  • So, the correct answer is 'True'.

The flagella of prokaryotic and eukaryotic cells differ in

  1. Microtubular organization and function.

  2. Type of movement and placement in cell.

  3. Location in cell and mode of functioning.

  4. Microtubular organization and type of movement.


Correct Option: D
Explanation:
Flagella are long, whip-like projection or appendages of cells used in motility. These are made up of microtubules (long, slender, protein tubes) and help propel cells and organisms in a whip-like motion. These are organelles defined by function rather than structure. There are large differences between different types of flagella pf prokaryotes and eukaryotes. The flagella differ greatly in protein composition, structure, and mechanism of propulsion. 
The flagellum of eukaryotes usually moves with an S motion and is surrounded by cell membrane. 

Rhizoplasts or rootlets, are the part of which of the following structure?

  1. Centriole

  2. Root hairs

  3. Ciliary apparatus

  4. Spindle


Correct Option: C
Explanation:

Rhizoplast is a fibril which is a connecting link between blepharoplast, with the nucleus in flagellated cells or organisms. It is a striated contractile structure attached to the basal region of the cilium in a variety of ciliates and flagellates. Many regulate the flagellar beat pattern, and is sensitive to calcium concentration. They are composed of a 20 kD protein, rather similar to spasmin. The ciliary rootlet or rhizoplast, is a cytoskeleton-like structure that originates from the basal body at the proximal end of a cilium. It extends proximally toward the cell nucleus. Rootlets are typically 80-100 nm in diameter and contain cross stria distributed at regular intervals of approximately 55-70 nm. 


So, the correct answer is option C.

The cilia and flagella arise from

  1. Basal bodies

  2. Basal granules

  3. Blepharoplasts

  4. All of the above


Correct Option: D
Explanation:

A basal body (synonymous with basal granule, kinetosome and in older cytological literature with blepharoplast) is an organelle formed from a centriole, and a short cylindrical array of microtubules. It is found at the base of a eukaryotic undulipodium (cilium or flagellum) and serves as a nucleation site for the growth of the axoneme microtubules. Centrioles, from which basal bodies are derived, act as anchoring sites for proteins that in turn anchor microtubules within centrosomes, and are known as the microtubule organizing center (MTOC).

Cartwheel structure is shown by

  1. Flagella

  2. Cilia

  3. Centriole

  4. All of the above


Correct Option: D
Explanation:

Centrosome is composed of two centrioles lying at right angles to each other. Each centriole has a cartwheel constitution. There is a whorl of nine peripheral triplet fibres of tubulin tilted at an angle of 40 degrees. In cilia and flagella also the cartwheel structure is present but the fibrils have 9+2 arrangement- peripheral doublet fibrils are tilted at an angle of 10 degrees.

The cilia and flagella both have

  1. 9 + 2 arrangement of microtubules.

  2. Protective structure of cells.

  3. Only present in protozoa animals.

  4. Only outgrowth structure of cytoplasm.


Correct Option: A
Explanation:

A cilium is an organelle found in eukaryotic cells. Cilia are slender protuberances that project from the much larger cell body. 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 microtubule singlets in addition to the nine outer doublets (called a 9+2 axoneme). A flagellum is a lash-like appendage that protrudes from the cell body of certain prokaryotic and eukaryotic cells. Flagella also has 9+2 arrangement of microtubules. They both contains inner growth along with outer growth of cytoplasm. They both are not the protective structures.