Question

1A. What group of plants do ferns belong to?

1B. Which stage of the life cycle is dominant in ferns?

1C. What advantages did the evolution of vascular tissue give to plants?

Answer 1

Ans1(A) : Ferns come under the Pteridophytes. A fern is a representative of the pteridophytes.

Ans 2(B) : The dominant phase in life cycle of ferns is sporophytic phase or sporophytic generation. Unlike bryophytes, in which sporophyte is dependent upon gametophyte physically & physiologically , the sporophyte is independent at maturity in pteridophytes, & hence the sprophytic phase is the dominant phase of life cycle instead of gametophyte.

Ans 3(C) Advantages of vascular system :

* transportation of resources (water, essential mineral nutrients, sugars & amino acids) effectively through vascular system to different parts of plant as vascular system provides a long channel for transportation , which was earlier not possible in bryophytes as their were absence of vascular tissues & only the primitive type of conducting system (presence of hydroids & leptoids ) in bryophytes was not sufficient ot meet the needs of plant.

* Growth & longer heights of plants having vascular tissues : Bryophytes specially mosses were very short plants , most of them being only few centimeters in length , as they possess only primitive coneucting system which cannot fulfil the needs of taller plants, but the evolution of vascular system resulted an increase in the height of plants due to higher growth by achieving greater availability of water, minerals , sugars etc. i.e. why plants after bryophytes were taller in their heights.

* Providing mechanical support : As the cell walls of vascular tissues are lignified, it provides mechanical strength to resist the pressure that gets created under the condition of tension in resource transportation column & prevents cell from collapsing.

* Vascular system acts as a communication channel among different parts of the plants, determining & regulating the needs of resources by different plants & thus fulfilling them.

Hope this will help you?