Tag: locomotion and reproduction

Quizzes (2) Questions (48)

Questions Related to locomotion and reproduction

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

Cartwheel structure is shown by

  1. Flagella

  2. Cilia

  3. Centriole

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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.
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

Tubulin binds colchicine and which of the following, at different binding sites?

  1. Vincristin

  2. Vinblastin

  3. Actin

  4. All the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Vincristin and Vinblastin are important anti cancer drugs, isolated from Althea rosea. These drugs inhibit spindle formation and thus arrest uncontrolled division of cancer cells. Tubulin are important cytoskeletal elements. Actin, Myosin are important for cellular movements. Motor proteins utilizing the cytoskeleton for movement fall into two categories based on their substrates: Actin motors such as myosin move along microfilaments through interaction with actin. 

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

Which of the following statements regarding cilia is not correct?

  1. Cilia contain an outer of nine doublet microtubules surrounding two single microtubules.
  2. The organized beating of cilia is controlled by fluxes of Ca$^{2+}$ across the membrane.

  3. Cilia are hair-like cellular appendages.

  4. Microtubules of cilia are composed of tubulin.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cilium is an organelle found in eukaryotic cells and are hair-like appendages. Inside cilia, is a microtubule-based cytoskeleton called the axoneme. The axoneme of cilia has a ring of nine outer microtubule doublets and two central microtubule singlets in addition to the nine outer doublets, called 9+2 axoneme.
The organized beating of cilia, however, are produced by controlled sliding of outer doublet microtubules.

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

Which of the cilia protein is analogous to myosin of muscles?

  1. Tubulin

  2. Dynein

  3. Flagellin

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Dynein forms an integral part of cilia. It is a motor protein which converts the chemical energy contained in ATP into the mechanical energy of movement. Dynein transports various cellular cargo by "walking" along cytoskeletal microtubules towards the minus-end of the microtubule, which is usually oriented towards the cell center. 

Axonemal dynein causes sliding of microtubules in the axonemes of cilia and flagella and is found only in cells that have those structures. There are parallels between the sliding filaments of skeletal muscle myosin and the sliding microtubules of cilia. Both are powered by ATP. Both motors dynein in cilia, myosin in skeletal muscle are ATPases. Both are regulated by calcium ions. 

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

Pattern of organisation of eukaryotic cilia and flagella is

  1. 9 + 0

  2. 9 + 1

  3. 9 + 2

  4. 9 + 3
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Cilia and flagella are cellular projections which are covered by an extension of the plasma membrane. 
  • They both have similar internal structures and are made up of microtubules.
  • The microtubule arrangement within cilia and flagella is 9 + 2 arrangement of microtubules.
  • It contains nine fused pairs of microtubules on the outer side of a cylinder and the two unfused microtubules at the centre.
  • So, the correct answer is '9 + 2'.
Multiple choice zoology locomotion and reproduction flagella other cell components single membrane bound organelles

9 + 0 arrangement is found in

  1. Flagellum

  2. Centriole

  3. Cilium

  4. Spindle fibres
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Centriole- The centrosome is made up of 2 centrioles which are right angled to each other and is composed of a protein known as tubulin.
  • It produces spindle apparatus at the time of cell division.
  • Each centriole has 9 peripheral groups of microtubules (triplet) with no central microtubules thus, this type of arrangement in centriole is called 9+0 pattern.
  • So, the correct answer is 'Centriole'.
Multiple choice zoology locomotion and reproduction flagella other cell components single membrane bound organelles

Number of dynein arms

  1. Four attached to subfibre B

  2. Two attached to subfibre B

  3. Two attached to subfibre A

  4. Four attached to subfibre A
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Dynein arms refer to the structures that extend clockwise from one tubule of each microtubule (nine doublets) towards the adjacent doublet in the axoneme of cilia or flagella.
  • Each axoneme contains eight or nine dynein heavy chains.
  • The inner and outer dynein arms are two-headed structures which contain two heavy chains each.
  • So, the correct answer is 'Two attached to sub fibre A'.
Multiple choice zoology locomotion and reproduction flagella other cell components single membrane bound organelles

The presence of cilia, an oral groove and food vacuoles and the absence of chloroplasts in an unicellular organism indicate that the organism carries on

  1. Sexual reproduction

  2. Autotrophic nutrition

  3. Extracellular digestion

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

The autotrophic organisms are self feeders that can synthesize the organic compounds using the inorganic substances available in surroundings. Green plants synthesize organic compounds using carbon dioxide and water in presence of sunlight as captured by green pigment chlorophyll. Absence of chlorophyll indicates the heterotrophic mode of nutrition of the organisms wherein they depend on the organic compounds synthesized by other autotrophs. This makes option B incorrect and option D correct. Option A is incorrect as the question is about mode of nutrition; not mode of reproduction. Extracellular digestion refers to secretion of digesting enzymes onto the food present in surroundings followed by intake of digested food via phagocytosis or any other transport mechanism. Cilia are the hair like appandages that help organism to move food into the oral groove which in turn collect and move the food into the cell; the food vacuoles serve to store the food. This makes option C incorrect as presence of cilia, oral groove and food vacuole indicate intracellular digestion. Correct answer is D.