Question

sugar cane has a high efficiency of carbon dioxide fixation because it performs
(a)Calvin cycle
(b)EMP pathway
(c)hatch and slack pathway
(d)TCA cycle

Answer 1

Hint: The metabolic pathway in plants where carbon fixation is done in bundle sheath cells by the enzyme RuBisCO. This is seen in ${ C }_{ 4 }$ plants such as sugar cane.

Complete answer:
Sugar cane can grow in dry tropical regions. Plants in these regions are adapted to perform the ${ C }_{ 4 }$ pathway. They are called ${ C }_{ 4 }$ plants. These plants have a high affinity for carbon fixation because they perform the ${ C }_{ 4 }$ pathway which is also known as Hatch and Slack pathway.
Other examples of plants that perform ${ C }_{ 4 }$ Pathway are maize, sorghum, corn. Etc.

Additional Information: -${ C }_{ 4 }$plants have special leaf anatomy and they can tolerate higher temperatures and can show responses to high light intensities.
- Photorespiration, a process generally found in ${ C }_{ 3 }$ plants is absent in ${ C }_{ 4 }$ plants.
- Production of biomass is more in ${ C }_{ 4 }$ plants
- ${ C }_{ 4 }$ plants have the 4 carbon compound oxaloacetic acid which is the first carbon dioxide fixation product.
- ${ C }_{ 4 }$ plants have a special type of Anatomical feature called Kranz Anatomy where vascular cells are surrounded by large cells called bundle sheath cells.
- Bundle sheath cells have a large number of chloroplasts, thick walls, no intracellular spaces and contain an enzyme called RuBiSco.
- Enzyme PEP carboxylase helps in carbon fixation in the mesophyll cells. ${ C }_{ 4 }$ plants lack this enzyme, so carbon fixation is performed by the enzyme RuBisCO present in the bundle sheath cells.
- The 4-carbon oxaloacetic acid is converted into malic acid or aspartic acid which is transported into bundle sheath cells where these acids are broken down into carbon dioxide and 3 carbon compounds.
So, the correct answer is the 'Hatch and Slack pathway'.

Note: The Calvin pathway occurs in mesophyll cells in ${ C }_{ 3 }$ plants and in ${ C }_{ 4 }$ plants it occurs in bundle sheath cells.
RuBisCO - Ribulose bisphosphate carboxylase-oxygenase.
Crassulacean Acid Metabolism(CAM) is an alternative pathway for ${ C }_{ 3 }$ and ${ C }_{ 4 }$ pathways for carbon dioxide fixation. It is found in plants that grow in hot and dry environments. Ex: plants belong to the Crassulaceae family ex: cacti.