Which free-living cells were the earliest contributors to the formation of Earthʹs oxidizing atmosphere?

#Question id: 19503

#SCPH05 I Biotechnology

#Question id: 76

#SCPH05 I Biotechnology

Which of the following illustrations is not a structural isomer of an organic compound with the molecular formula C6H14? For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted.

#Question id: 2318

#SCPH28 | Zoology

What plant organelle serves a function similar to that of animal lysosomes?

#Question id: 11799

#SCPH05 I Biotechnology

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: 12714

#SCPH06 I Botany