Question

In an anther, stomium occurs
A. At the tip
B. In groove of each anther lobe
C. At the base of anther
D. Transversely on the anther

Answer 1

Hint: Stamen is the essential whorl of a flower and is a male reproductive part. It consists of anther and filament. Anther is a terminal structure. It consists of two lobes so called as bilobed. Filament is a long and slender stalk. It is attached to the thalamus of the flower.

Complete answer:
Structure of Typical Anther
A typical anther is bilobed consisting of two lobes. The two anther lobes are separated by a deep groove where line of dehiscence occurs in front and are attached to each other by a band of vasculated sterile tissue called connective.
Each anther is a four sided tetragonal structure consisting of four microsporangia located at corners, two in each lobe as it is bilobed. Hence, a mature anther is tetrasporangiate.
Microsporangia forms pollen sacs the structure which helps in fertilisation which on maturity become filled with pollen grains.
Stomium is the structure which marks the line of dehiscence.

Now let us match this with given options:-
At the tip :- at the tip of the anther lobes are present but these lobes do not play any role in the dehiscence so stomium is not present here.
In the groove of each anther lobe :- The two anther lobes are separated by a deep groove where line of dehiscence occurs in front and stomium is the structure which marks the line of dehiscence. Thus this option is correct.
At the base of anther :- at the base of the anther filament is present. It is a long stalk-like structure . This remains attached to the thalamus or petals of the flower. This structure connects anther to the ovary.
Transversely on the anther :- when we see the transverse section of the anther it shows different structures as lobes and microsporangium but stomium is not present.

Our required answer is b that is in the groove of each anther lobe.

Note: As the anthers mature and dehydrate, the microspores dissociate from each other and develop into pollen grains. Inside each microsporangium, several thousands of microspores of pollen grains are formed that are released with the dehiscence of anther Epidermis.