General Instructions:
- Copy the given assignment of practical in fair practical copy of biology.
- Make the use of black pen for heading and sub-headings and blue pen for writing other content.
- Work should be presentable.
- Make well labelled and proper diagram as provided in this assignment.
Spot No.2
Aim: To observe flower adapted for pollination by insects.
Materials Required: A ficus plant, forceps, needle notebook
Theory: Insects pollinated flowers rare large brightly to attract insects. They produce fragrance and nectar to attract insects. They produce a moderate quantity of pollen. The pollen are often sticky to sticky to the insect body. Another adaptation of insect pollinated flower is that their stigma lies inside the flower so that the insect brushes against it.
When the flowers are small and inconspicuous, they are collected together into a dense inflorescence to become attractive and showy.
Procedure:
- Study the various parts of the flower.
- Observe the insects which visit these flowers.
Observation:
- Ficus has hypanthodium inflorescence.
- There is narrow orifice for entry of insects, within which there are three types of flower(male flower, female flower and neutral flower)
- The male flower are situated near the orifice, while lower down are long styled female and short styled neutral flower.
- Figs are pollinated by gall wasp which crawls into receptacle and lays eggs inside the ovules of gall flower which can easily reach through its ovipositor because of short style. Each egg develop larvae which feds on ovules and forms galls.
- The larva develops into mature wasp and crawl out of figs. In doing so they brush against male flower carrying away pollen gains on their body. These pollen laden insects the enter fresh figs thus pollinating long styled female flower and lay egg within the gall flower in their returns
Precautions:
- Always take fresh flower to study the features.
- Carefully observe the insects which visit the flower.
