Tag: cell: size and differentiation

Questions Related to cell: size and differentiation

Which organelle occurs both in plants and animals

  1. Cell wall

  2. Mitochondria

  3. Centriole

  4. Chloroplast.


Correct Option: B

Beside the nucleus, which of the following cell organelles play an important role in hybrid vigor?
a. Lysosome
b. Mitochondria
c. Endoplasmic reticulum
d. Plastid
Select the correct answer using the codes given.

  1. $1$ and $2$

  2. $1$ and $4$

  3. $2$ and $3$

  4. $2$ and $4$


Correct Option: A
Select the incorrect match from the following.
  1. Terpenoids - Monoterpenes

  2. Lectins - Concanavalin A

  3. Toxins - Anthocyanins

  4. Drugs - Vinblastin


Correct Option: C
Explanation:
 Some Secondary Metabolites Some Secondary Metabolites 
 Pigments  Carotenoids, anthocyanins, etc. 
 Alkaloids Morphine,Codeine ,etc. 
 Terpenoids Monoterpenes, Diterpenes, etc. 
 Essential oils Lemongrass oil,etc. 
 Toxins Abrin,Ricin 
Lectins  Concanavalin A 
 Drugs Vinblastin, Curumin, etc. 
 Polymeric substance  Rubber,Gums,Cellulose. 

So, the answer is 'Toxins - Anthocyanins'.

The chromosome in which centromere lies slightly away from the middle of the chromosome resulting into one shorter arm and one longer arm, is called as
  1. Metacentric

  2. Submetacentric

  3. Acrocentric

  4. Telocentric


Correct Option: B
Explanation:

In submetacentric type of chromosome, the centromere lies at some distance away from the midpoint, dividing the chromosomes into two unequal arms.

So, the correct answer is 'Submetacentric'

How does a cell rid itself of defective or malfunctioning organelles?

  1. They are engulfed by plastids and stored until export from cell is possible

  2. Defective parts accumulate until the cell itself dies

  3. They are exported by exocytosis

  4. Lysosomes assist in the removal of defective organelles by digesting them


Correct Option: D
Explanation:

The lysosomes may be called "suicide bags" of the cell in view of their autolytic role, or "disposal units" of the cell because they digest the incoming food materials and remove the foreign bodies, toxic molecules, and debris; or "recycling centres" as they break down warn out and defective cells and cell organelles to component molecules for building new organelles and cells.

Cell cultures of Lithospermum erythrorhizon are being used commercially for preparing.

  1. Berberine

  2. Plamitine

  3. Shikonin

  4. Plumagin


Correct Option: A

Nucleoprotein structures found at the end of chromosome are

  1. Centromere

  2. Telomeres

  3. Satellites

  4. Centrosomes


Correct Option: B
Explanation:
  • Telomeres are essential nucleoprotein structures at the ends of eukaryotic chromosomes. They play several essential roles preserving genome stability and function, including distinguishing chromosome ends from DNA double-stranded breaks (DSBs) and maintenance of chromosome length.
  • The centromere is the point of attachment of the kinetochore, a structure to which the microtubules of the mitotic spindle become anchored.
  •  Satellite DNA consists of very large arrays of tandemly repeating, non-coding DNA. Satellite DNA is the main component of functional centromeres, and form the main structural constituent of heterochromatin.

So, the correct answer is 'Telomeres'.
Read the given statements.

(i) Centromere is present in the middle of the chromosome and forms two equal arms.
(ii) Chromosome has a terminal centromere.
(iii) Centromere lies close to the end of the chromosomes forming one extremely short and one very long arm.
(iv) Centromere lies slightly away from the middle of the longer arm.

Select the correct option as per the codes given above.
  1. $Metacentric - (i), Submetacentric - (iv), Acrocentric - (iii), Telocentric - (ii)$

  2. $Metacentric - (i), Submetacentric - (ii), Acrocentric - (iii), Telocentric - (iv)$

  3. $Metacentric - (iv), Submetacentric - (i), Acrocentric - (iii), Telocentric - (ii)$

  4. $Metacentric - (iv), Submetacentric - (ii), Acrocentric - (iii), Telocentric - (i)$


Correct Option: A
Explanation:

metacentric chromosome - has centromere in the center with arms of identical length on either sides (p=q) telocentric chromosome: has centromere at terminal end, one single arm, not distinguished as p and q sub metacentric chromosome: centromere slightly away from the centre, forming two unequal arms - p -shorter and q-longer acrocentric chromosome : centromere farther away from the center, closer to the terminal end. forms unequal arms, p-much shorter, q- quite longer. So, the correct answer is 'Metacentric−(i),Submetacentric−(iv),Acrocentric−(iii),Telocentric−(ii)'

Rapid and irreversible cell elongation occurs commonly in plants but not in animals. This difference is due to the.

  1. Presence of chloroplasts and mitochondria

  2. Absence of centrioles and Golgi bodies

  3. Absence of endoplasmic reticulum and presence of large vacuoles

  4. Presence of large vacuoles and cell walls


Correct Option: A

The chromosome in which centromere lies slightly away from the middle of the chromosome resulting into one shorter arm and one longer arm, is called as _____________.

  1. Metacentric

  2. Submetacentric

  3. Acrocentric

  4. Telocentric


Correct Option: B
Explanation:
In submetacentric type of chromosome, the centromere lies at some distance away from the midpoint, dividing the chromosomes into two unequal arms.
So, the correct answer is 'Submetacentric'