Question

Secondary xylem is absent in (1)Mangofera (2)cicer (3)zea mays (4)Ficus​

Answer 1

Secondary xylem is the extra xylem that grows in woody plants as a part of secondary growth.

Explanation:

Secondary xylem is the extra xylem that grows in woody plants as a part of secondary growth.

• Xylem is the vascular tissue which transports water and nutrients to the plant. Water absorbed from the soil is supplied throughout the plant.
• Xylem maybe classified as primary or secondary depending on their place of origin and growth.
• Primary xylem is the xylem formed during the initial growth phase, it originates from the procambium.
• Secondary xylem originates from the cambium, it is prominent among woody trees indicating higher development. These form the growth rings of a tree, which are used to determine the age of a tree.

Zea mays (corn plant) does not have a secondary xylem. It is the only plant which is not woody hence lacks a secondary xylem.

Answer 2

(3) is the correct option.

The secondary xylem is the name given to the xylem that is the result of secondary growth and makes the plant woody:

• The xylem is the vascular part of a plant that is responsible for the distribution of water and nutrients from the roots to all the parts of the plant.
• The primary xylem arises from procambium and is the result of primary growth in terrestrial plants.
• The secondary xylem on the other hand arises from the vascular cambium and is formed from secondary growth.
• Secondary xylem is not present in non-woody plants hence, Zea mays (maize) is the only option that does not contain secondary xylem.