SSC MTS EXAM

SSC

BIOLOGY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Why must radioactive CO2 be used when tracing phloem flow?
A
It is incorporated into the phloem cells
B
It is incorporated into the minerals in the phloem
C
It is incorporated into the sucrose during cellular respiration
D
It is incorporated into the sucrose during photosynthesis
Explanation: 

Detailed explanation-1: -During photosynthesis, plants take in carbon dioxide (CO2) and water (H2O) from the air and soil. Within the plant cell, the water is oxidized, meaning it loses electrons, while the carbon dioxide is reduced, meaning it gains electrons. This transforms the water into oxygen and the carbon dioxide into glucose.

Detailed explanation-2: -Translocation occurs in the phloem tissues, which consist of tube-like vessels called phloem vessels. These phloem vessels run from the leaves into every other part of the plant and are responsible for transporting dissolved organic solutes, such as sucrose and amino acids, from the sources to the sinks.

Detailed explanation-3: -Water follows the sugar molecules into the sieve elements through osmosis (since water passively diffuses into regions of higher solute concentration). This water creates turgor pressure in the sieve elements, which forces the sugars and fluids down the phloem tubes toward the sinks.

There is 1 question to complete.