Trends of gametophyte in evolution of plants
Explain the trends of gametophyte in evolution of the plants?
Expert
A tendency of gametophyte evolution within the plants has been towards the formation of the gametes which are independent from the water. In the bryophytes and in the pteridophytes the fecundation is totally dependent upon the water. Within the phanerogamic plants such dependency is not there.
Another tendency includes the reduction in size and duration of the gametophyte. In bryophytes, the gametophyte is the lasting stage. In pteridophytes, gymnosperms and angiosperms became the temporary stage and its relative size was successively decreased.
A third evolutionary trend is related to the interdependency between the gametophytes and sporophytes. In bryophytes, the sporophyte is solely dependent upon the gametophyte in order to survive. In the remaining plants, the sporophyte refers to the independent stage and the once autotrophic gametophyte in the bryophytes and pteridophytes became dependent on the sporophyte in phanerogamic plants.
Is the mammalian embryonic growth indirect or direct? Answer: In mammals, the embryonic growth is direct, devoid of larval phase.
Name the five kingdoms into which living beings are classified? Which class of living being is out of this categorization?
Mass transportation across cell membrane: Mass transportation is the entrance or existence of substances in or from the cell engulfed by portions of membrane. The fusion of internal substance having membranous vesicles with the cell membrane is termed
It is just the reverse of the downward communication. It flows upward from a subordinate to the superior through middle managerial levels along the line. Such communication is of two types: Feedback if information in which subordinates convey a message to the top executive in response to
What is Seminal Fluid. Explain the characterstics of the Seminal Fluid.
If provided a territory and a list of physicians to call on, how would you go regarding it?
Concerning events throughout the periods of life how dissimilar is the gametogenesis in female and in male?
Explain the Dimension Table?
What is the relation among the concepts of chromosome and chromatin? Are heterochromatin and euchromatin portion of chromosomes?
Write down the most abundant form in which nitrogen is found in nature.
18,76,764
1933918 Asked
3,689
Active Tutors
1448179
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!