Question

Explain how each evolutionary change seen in the life cycles of seedless non-vascular plants, seedless vascular plants, non-flowering seed plants, and flowering seed plants reflects adaptations to land. In your explanation, explain why each plant group is more successful on land than the ancestral group before it.

Answer 1

Non vascular plants do not posses vascular tissue for the conduction of water and food as these plants do not grow vertically much, they grow in damp and moist surfaces so their each cell can directly absorb required water from surrounding and also those plants do not have true stem, true leaf and true root.

But soon they started to live on Terrestrial mode and do not require water for fertilization. So now they have to develop an stage which can persist even without water. So they started to produce seed.

Because seed can pass the unfavourable conditions like scarcirty of water and high temperature until favourable condition comes.

Now as the plants grow on dry land and grows vertically due to true stem, and true roots plants now need vascular tissue to transport water to the tip of plants food vice versa.

Next I'm evolution plants with flowers comes, because plants with attractive flower have a well developed mechanism of transfer of pollen grains. Those plants which produce flowers attract insect and other pollinators, these pollinator transfer pollen grains to the suitable receiver without wastage of grains. Previously without flowers only air and water like vectorless method are used by plants which are totally directionless mechanism causes losses of several pollens.