Question

In a raceme, the flower arrangement is?
A. Basipetal
B. Centripetal
C. Centrifugal
D. Acropetal

Answer 1

Raceme arrangement is a type of racemose inflorescence. It is characterized by the continuous growth of the main axis with younger flowers at the apex and older ones at the base. It is seen in radish. The peduncle contains bisexual flowers.

Complete answer:
Inflorescence refers to the pattern of arrangement of flowers on the axis. It is mainly of two types called a racemose and cymose inflorescence. Inflorescence types can be used in the determination and classification of flowering plants. These are further divided into several subtypes. Raceme inflorescence is a sub-type of the racemose inflorescence. A raceme is defined as an unbranched and indeterminate type of inflorescence. The flowers of a raceme have short floral stalks called pedicels along the axis (shoot) of the inflorescence. These are called pedicellate flowers. The oldest flowers in a raceme are found at the base and the younger flowers are found at the apex of the shoot. The flowers together form a cluster that is attached by short equal stalks at equal distances. Thus, it shows the acropetal arrangement of flowers which is evident in radish. A raceme can have a branching axis which is called a compound raceme. A spike is a similar inflorescence to a raceme but its flowers lack stalks. The black cohosh plant shows a showy raceme inflorescence. A centripetal arrangement means that younger flowers occur in the center and the older ones are found at the periphery. The basipetal inflorescence is the opposite of acropetal.
So, we can conclude from the above discussion that the right answer is option D.

Note: The cymose inflorescence as compared to the racemose inflorescence is characterized by the termination of stalk growth due to flower formation. Most of the racemose inflorescences are in an acropetal manner. The other types of the inflorescence are also present and are termed as special inflorescences.