In angiosperms the eggs?
In angiosperm the egg is surrounded by a wall only at the micro pylar end.
About 7% of the total world production of iodine is obtained by which algae?
Iodine is found in algae Laminaria in which approximately 7% of total world production of iodine is obtained by which algae.
Moss plant is a
Mosses are heterosporous, which means they make two distinct types of spores; these develop into male and female gametophytes.
In pteridophytes, prothallus produces
In pteridophytes, the spore is a haploid structure, which develops after meiosis of spore mother cell. On germination, it gives rise to a green haploid prothallus (gametophyte) which is monoecious, i.e., has both antheridia (male sex organs) and archegonia (female sex organs) in homosporous pteridophytes.
A plant has rhizoids and is haploid. It needs water to complete its life cycle because the male gametes are motile. Identify the group to which it belongs.
The plant body of bryophytes is not completely differentiated into roots, stems and leaves. They have small minute structures called rhizoids instead of roots. They are non-vascular plants. Water is necessary for reproduction in bryophytes. They have two stages in the life cycle. One is the gametophyte stage and second is the sporophyte phase. In their gametophyte phase, sperms and eggs are produced. The sperms can move through the water and reach the eggs to perform fertilization.
Identify the alga known for biological activity called bioluminescence.
Noctiluca also was known as sea sparkle is a bioluminescent algae which grows so abundantly that water sparkles blue light at night which helps in keeping away predators also.
Red algae possess
Red algae are defined as eukaryotic algae that possess chlorophyll a, d and phycobilins. They contain Floridian starch as a food reserve and are abundant of phycocolloids (like agar, carrageenin) but lack flagellate cells.
Vascular cryptogams are
Cryptogams are defined as lower plants or plant-like organisms that reproduce by spores. Vascular Cryptogams refers to those vascular plants that do not make seeds.
Assertion: The primary protonema of moss may break into fragments by death and decay of cells.
Reason: Each fragment gives rise to a leafy gametophyte.
The haploid spores on germination give rise to alga-like filamentous branched portion called Primary Protonema. This protonema develops buds, from which leafy gametophyte arises. Sometimes this primary protonema breaks up into small fragments accidentally, and these fragments give rise to leafy gametophores.
Experiments demonstrating the importance of the nucleus in controlling the growth of the cell was performed in
Nucleus is a double membrane-covered protoplasmic body that contains hereditary information. With the help of grafting experiments on Acetabularia, Hammerling (1953) proved that nucleus is a store-house of hereditary information and hence, controls growth because growth depends on proteins synthesized and protein synthesis depends on the hereditary information.
Identify the character which is absent in Fucus?
The male reproductive structure in Fucus is called antheridiophores which are branched, tree-like structures that line the conceptacles. They have terminal inflated antheridia on their branches and undergo meiosis. They have 64-128 biflagellate male gametes.
Ancestors of land plants were
Research shows that the closest relatives to land plants are actually conjugating green algae such as Spirogyra. Ancestors of green plants began to colonise the land about 500 million years ago, and it is generally accepted that they evolved from streptophyte algae (a group of green, freshwater algae).
The highly advanced division of plant is:
The highly advanced division of the plant kingdom is Angiosperms.
(a) Spores are always of two kinds
(b) Vascular Tissues are present
(c) The sporophyte is parasitic over the photosynthetic gametophyte
(d) The development of zygotes into young embryos takes place within the female gametophytes.
The sporophyte is the dominant stage in the life cycle of Pteridophytes. It is not parasitic over the gametophyte. All the other statements are correct.
In pteridophytes, prothallus produces
In pteridophytes, the spore is a haploid structure, which develops after meiosis of the spore.