Companion cells in minor veins of mature leaves. All three cell types have dense cytoplasm and abundant mitochondria, there are three types companion cells  present in column A while its characteristics given in column B;

             COLUMN A                                                             COLUMN B

A) Ordinary companion cells              i) appear well suited for taking up solutes via cytoplasmic connections numerous plasmodesmata connecting them to bundle sheath cells. Its having numerous small vacuoles, as well as poorly developed thylakoids.

 

B) Transfer cells                                    ii) have chloroplasts with well-developed thylakoids     and a cell wall with a smooth inner surface. The number of plasmodesmata connecting ordinary companion cells to surrounding cells.

C) Intermediary cells                          iii) the development of fingerlike wall in growths, particularly on the cell Walls. These wall ingrowths greatly increase the surface area of the transfer cell’s  plasma membrane, few plasmodesmata connect this type of companion cell to any of the surrounding cells except its own sieve element.

Which of the following correct combination;

#Question id: 3685

#Section 3: Genetics, Cellular and Molecular Biology

In prokaryotes, DNA replication begins at a single site that is rich in AT nucleotide sequence, where two strands unwind and separate. This ATP dependent process catalyzed by a protein

#Question id: 3686

#Section 3: Genetics, Cellular and Molecular Biology

The short strand of ........ primer is required for the replication of DNA:

#Question id: 3687

#Section 3: Genetics, Cellular and Molecular Biology

As the two strands of the double helix are separated, the positive supercoiling interferes with the further unwinding of DNA. Which of the following enzyme makes a break in a strand of DNA to release the supercoiling and facilitate the replication to occur?

#Question id: 3688

#Section 3: Genetics, Cellular and Molecular Biology

Which of the following enzyme has a unique ability to introduce positive and negative supercoiling of the DNA and it is the target for antibacterial agents such as ciprofloxacin/quinolones?

#Question id: 3689

#Section 3: Genetics, Cellular and Molecular Biology

DNA replication is bidirectional and anti-parallel. Which of the statement is FALSE regarding the DNA replication?

#Question id: 3690

#Section 3: Genetics, Cellular and Molecular Biology

The DNA polymerase is a template-directed enzyme that synthesizes new complementary strand from a parent strand but it requires the existing short nucleotide sequence for its elongation. Which of the following enzyme is required for the synthesis of this primer?