What are the trends of the gametophyte, Biology

Assignment Help:

What are the trends of the gametophyte in the evolution of plants?

A tendency of the gametophyte evolution in plants has been towards the formation of gametes that are independent from water. In bryophytes and in pteridophytes the fecundation is totally dependent on water. In phanerogamic plants such dependency does not exist.

Another tendency is the decrease in the size and duration of the gametophyte. In bryophytes the gametophyte is indeed the lasting stage. In pteridophytes, gymnosperms and angiosperms it became the temporary stage and its relative size was successively decreased.

 

A third evolutionary trend relates to the interdependency among gametophytes and sporophytes. In bryophytes the sporophyte is entirely dependent on the gametophyte to survive. In the remaining plants the sporophyte is the independent stage and the once autotrophic gametophyte in bryophytes and pteridophytes became dependent upon the sporophyte in the phanerogamic plants.

 


Related Discussions:- What are the trends of the gametophyte

Defense mechanisms used in diabetes mellitus, Q. Defense mechanisms used in...

Q. Defense mechanisms used in Diabetes Mellitus? Defense mechanisms are the strategies to cope with the real situation and to maintain self-image. Healthy persons normally use

Explain particle movement , Explain Particle Movement ? Particle Mov...

Explain Particle Movement ? Particle Movement :  Particles are moved down a concentration gradient by the process of diffusion. Osmosis is simply the diffusion of water acr

Animals, explain the modes of nurition in animals

explain the modes of nurition in animals

Three sources of energy which do not depend on fossil fuel, Name three sour...

Name three sources of energy which do not depend on fossil fuel. Sources of energy which do not rely on fossil fuel are water (hydroelectric generation), wind, tidal power, wav

Define blank titration for saponification number of fats, Define Blank Titr...

Define Blank Titration for Saponification Number of Fats? Pipette 5 ml of alcoholic KOH in a 250 ml conical flask. Titrate against standardized HCI using phenolphtalein as an i

Some common air pollutants, The major air pollutants are: (i)     Carbo...

The major air pollutants are: (i)     Carbon monoxide, CO (ii)   Nitrogen oxides, (NO)x (iii) Sulphur oxide, (SO)x (iv) Ground level ozone (O3) (v)   Hydrocarbons (

Closed mitral valvotomy-mitral valve disease, Closed Mitral Valvoto...

Closed Mitral Valvotomy :  This has been 1-eplaced by balloon mitral valvotomy (BMV) in most centres. It is done in cases of either pure mitral stenosis or with .triv

Explain about the endocrine system, Why is the endocrine system considered ...

Why is the endocrine system considered one of the integrative systems of the body? What is the other physiological system that also has this function? The endocrine system is s

Pressure and continuity, Pressure and Continuity Pressure Water...

Pressure and Continuity Pressure Water pressure increases with depth which varies in the ocean from 1 atmosphere where at the surface to 1000 atmosphere at the greatest

Estimation of burn area, Estimation of Burn Area: The  estimation of  ...

Estimation of Burn Area: The  estimation of  the  extent  of  burn area expressed as  the  percentage  of  the surface  area  of  the skin  burnt to  the  total body  surface

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd