Origin of Bryophytes II Pteridophytean Hypothesis II Algal Hypothesis II Botany optional II UPSC

. Channel Created and Managed by Dr. Pravin Ekade Contact - 8975045465 Nothing definite and very little information is available about the origin of bryophytes. All the views regarding the origin of bryophytes are depending upon the evidences like comparative morphology of the living plants, ontogeny of living plants and analogies with the living plants of other groups. Bryologists are divided on two fronts about origin of bryophytes, these are.. 1) Pteridophytean Hypothesis 2) Algal Hypothesis 1) Pteridophytean Hypothesis: the follower of this camp holds that the bryophytes are descended from Pteridophytes. The supporter of this hypothesis formulated their views on the basis of two features, these are.. (1) Close similarity between the Reproductive organs of bryophyte and Pteridophytes. (2) Similarities between the sporogonium of Anthoceros and the terminal sporogonium of the fossil pteridophytes such as Sporogonites and Horoneophyton. Beside this, these two groups also shows the similarities such as 3) Similarity in their pigments 4) Similarity in the structure of cell wall 5) Similarity in Food reserve 6) Similarity in reproductive methods and life cycles Due to all these similarities the follower of these groups strongly presume that bryophytes are evolved from the pteridophytes by "Progressive Simplification or Reduction". This view of origin of bryophytes is strongly supported by Scholars like Scott, Lang, Haskall, Kashyap and others. Rejection of Pteridophytean Hypothesis: The opponent of this hypothesis point out to the complete absence of any relic of the lost vascular system in the sporophyte of all today's bryophytes. This is why Pteridophytean Hypothesis is now stand discarded. 2)Algal Hypothesis: The supporter of this hypothesis believe in the aquatic ancestry of the bryophytes. That is, they hold that bryophytes are originated from the algae. The supporter of this hypothesis formulated their views on the basis of following similarities between algae and bryophytes. (1) The presence of flagellated sperms in in bryophytes which require the water for fertilization is the strong sign that bryophytes have aquatic origin. (2) The similar development of green filamentous algae like protonema structure as a juvenile stage in some bryophytes is again a strong sign that these bryophytes have their origin in algae. Within the algal groups, bryophyta shows more similarities with green algae as compare to brown algae, such as. (3) Both have identical photosynthetic pigments (4) Both shows thallus like plant body (5) Both lack vascular tissues (6) Both have Starch as food reserve (7) Both have cellulose in their cell wall The Algal Hypothesis is supported by scholar like Bower, Cavers, Smith, Cambell and Fritsch. Now the algal ancestry of bryophytes is accepted by the botanist. This video is useful for the examinations like Botany optional for CSM and IFoS Mains Conducted by Union Public Service Commission (UPSC) Botany optional for UPPSC Mains Examination conducted by Uttar Pradesh Public Service Commission (UPPSC) Botany optional for West Bengal Civil Services (WBCS) Mains examination conducted by West Bengal Public Service Commission (WBPSC) Botany optional for BPSC Mains Examination Conducted by Bihar Public Service Commission (BPSC) Botany optional for OPSC Mains Examination Conducted by Odisha Public Service Commission (OPSC) Botany optional for JKPSC (KAS) Mains Examination Conducted by Jammu and Kashmir Public Service Commission (JKPSC) Botany optional for UKPSC Mains Examination Conducted by Uttarakhand Public Service Commission (UKPSC) Botany optional for RPSC – ACF and FRO Mains Examination Conducted by Rajasthan Public Service Commission (RPSC) Botany optional for MPPSC State Forest Service Mains Examination Conducted by Madhya Pradesh Public Service Commission (MPPSC) Botany Syllabus of APPSC for the post of Forest Range Officer (RFO) Conducted by Arunachal Pradesh Public Service Commission (APPSC) Botany Syllabus of MPSC for Meghalaya Forest Service (MFS) (ACF) Conducted by Meghalaya Public Service Commission (MPSC) – MPSC MFS Mains Examination Master of Science (M.Sc.) Botany Post Graduation Examination Bachelor of Science (B.Sc.) Botany Graduation Examination National Eligibility Entrance Test (NEET) Examination 11th and 12th Biology Subject Examinations #upsc #botany #biology #neet #bryophytes