The small, heart-shaped gametophyte called a prothallus is part of the life cycle of ferns. So, the correct option is (b).
A fern (Polypodiopsida or Polypodiophyta) is a type of vascular plant that reproduces through spores and lacks both seeds and flowers. Vascular plants have xylem and phloem. Their vascularity, or the presence of specialised tissues that conduct water and nutrients, sets them apart from mosses and other bryophytes.
A fern's prothallus is a flat, green, autotrophic, cordate (heart-shaped), dorsiventral, free-living, autonomous, nonvascular gametophyte that ranges in size from 1/8 to 113 inches (5-l0 mm). Typically, the gametophyte stage of the life cycle is known as the protothallium or prothallus. The spore that germinates becomes the prothallium.
Learn more about prothallus here:
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I think the right answer is D
Answer:
The region of retina devoid of photoreceptor cells (rod cells and cone cells)
Explanation:
The retina is the layer of the eyeball and is packed with rod cells and cone cells responsible for night and day vision respectively. The blind spot is the region in the retina where no rod cells and cone cells are present.
Absence of these photoreceptor cells ensures that no vision is formed in this part of the retina. However, the blind spot serves as the site from where the optic nerve passes through the retina and serves to transmit the impulse to the brain.
Answer:
Homologous structures can be described as the structures which are similar to one another present in different organisms. These similarities depict that the organisms might have a common ancestor i the past. For example, the forelimb of man, birds, dogs.
Analogous structures can be described as structures in different organisms which perform the same function but might not have a common origin. For example, the wings of bats and birds.
I think the answer is Passive
