"Agar-agar" is obtained from :-
Motile stages are not found in life cycle of :-
Embryo is not formed in thallophyta due to :-
Thallophyta (algae) reproduce sexually when male gametes and female gametes fuse to form zygote. Zygote immediately undergoes meiosis and it gives haploid gametes. Thus, embryo is not formed.
So, the correct option is 'Zygotic meiosis'.
Oogonia of Thallophyta differs with archegonia of bryophyta :-
Which of the following best explains the evolution of sexual reproduction :-
Chlamydomonas is best example for the evolution of sexual reproduction as the evolution of sex in algae has not taken place in any one phylogenetic line. This has taken place along several independent lines. For example, in Volvocales, where Gonium is isogamous, Pandorina slightly anisogalnous, Eudorina and Pleodorina marked by anisogamy and Volvox oogamous. It is correlated with the evolution from isogamy to oogamy through anisogamy. Whereas on the other hand, in another genus of Volvocales, i.e., Chlamydomonas, where species within the genus show all gradations from isogamy to oogamy, e.g., Chlamydomonas snowiae is isogamous, C. braunii is anisogamous and C. coccifera is oogamous.
Thus, the correct answer is option A.
Cephaleuros, which causes "Red rust of tea" is a :-
Heterotrichous habit is common among :-
Gametes are non-motile in :-
Due to which pigment red algae are capable of surviving in deep sea :-
Blue - green Agae resembles more closely to:-
Which of the following statement is true for algae :-
In which plant group reproductive organs are not enclosed in a layer of sterile cells:-
Classification of algae is mainly based up on :-
Classification of algae is mainly based upon the nature of their pigments.
Red Algae (Rhodophyceae) are characterized by the pigments - Phycoerythrin and Phycocyanin.
Brown Algae (Phaeophyceae) are brown due to the pigment Fucoxanthin.
Green Algae (Chlorophyceae) are characterized by pigments Chlorophyll-a, b, Carotenes, Xanthophyll. Hence option C is correct.
A prokaryotic autotrophic nitrogen fixing symbiont found in
Female sex organ of algae is called :-
A species of yellow-green alga called Vaucheria sessilis is an example of a sexually reproducing alga. The reproductive structures consist of an antheridium, which contains male gametes, and two oogonia, which contain female gametes.
Change in colour of algae according to depth in sea is called :-
Bioluminescence is a phenomenon associated with
Origin and evolution of sex in algae is best seen in
The green algae are a large, informal grouping of algae consisting of the Chlorophyta and Charophyta/Streptophyta, which are now placed in separate divisions, as well as the potentially more basal Mesostigmatophyceae, Chlorokybophyceae and Spirotaenia.
Cilia & flagella are absent in life cycle of :–
Which algae best explains the evolution of sexual reproduction :–
Clamydomonas and Ulothrix in green algae best explains the evolution of sexual reproduction.
The first sexuality was seen in the Clamydomonas and Ulothrix in the from of isogamy that the gamates formed were of plus and minus strains. Next evolution is seen is the ansiogamy that the gametes are of different size. Hence, the correct option is Option A.
The further more advanced evolution in the sex repdroduction is seen in the red algae and brown algae. so the Options B and C are not correct.
Spermatia are male gametes of :–
Cap cells occur in :-
Algae which have food conducting tubes similar to phloem in vascular plants are :-
Chlorophyll 'c' , 'd' and 'e' are characteristic pigments of respectively :-
The brown algae contains xanthophyll pigment fucoxanthin, chlorophyll 'a' and 'c' (no chlorophyll b), beta-carotene.
Red algae contain chlorophyll 'a' and 'd' as well as phycobilins, red and blue pigments involved in photosynthesis.
Yellow green algae contains chlorophyll 'a' but lack chlorophyll 'b'. They possess chlorophylls 'e' or 'c'. Besides these they also possess xanthophylls and beta carotene.
Therefore, the correct answer is option B.
Which of the following algae produces synzoospores :-
Reserve food of algae and fungi are :-
About 90 percent of total photosynthesis in the world is caused by :-
The fact that the land surface is covered in plants, not algae, indicates that plants are the most effective photoautotroph in most terrestrial habitats. In the open ocean, however, you will find mostly microalgae and some cyanobacteria, such as Prochlorococcusare particularly numerous. If you are wondering why these algae, which have a higher photosynthetic efficiency (measured as carbon fixed per quantity of photons), lose out to plants on land, then the short answer is that efficiency very rarely confers a reproductive or competitive advantage in biology.
As for why cyanobacteria and microalgae are more efficient at photosynthesis, it is mostly because they are small, (usually) single-celled, and have a enzymes to actively pump carbon dioxide into their cells (plants rely on passive diffusion). Being small gives them a very high surface-to-volume ratio. Being single-celled means that all cells are doing photosynthesis as opposed to a plant which needs to feed non-photosynthetic tissues. The carbon dioxide pumping enzymes lets cyanobacteria and microalgae avoid some of the harmful byproducts of photosynthesis that accumulate when there isn’t enough carbon dioxide in the cell to match the supply of energy from the light reactions.
Which type of algae are helpful in nitrogen economy :-
Sea weeds belong to :-
Plants of thallophyta are :-