Govt. Exams
Entrance Exams
The micropyle is a small opening in the integument through which the pollen tube enters the ovule to reach the embryo sac for fertilization.
The most definitive character for embryo classification is the number of cotyledons: monocots have one, dicots have two. This is evident even at the embryonic stage.
In bryophytes, the sporophyte is reduced (2n generation) and dependent on the dominant gametophyte. This reflects their primitive nature in plant evolution.
Gymnosperms produce naked seeds not enclosed in a fruit and lack true flowers. Angiosperms have enclosed seeds within fruits and possess flowers.
Xylem in pteridophytes consists of tracheids and vessels. Companion cells are found only in angiosperms associated with phloem.
Bryophytes have a dominant gametophytic generation, while the sporophyte is dependent on the gametophyte. This is unique among land plants and represents their primitive nature.
Sexual reproduction involves fusion of two gametes from different parents, resulting in genetic variation and equal parental contribution in diploid offspring.
Gymnosperms have naked seeds not enclosed in an ovary. Seeds enclosed in an ovary is a characteristic of angiosperms.
Rhizoids are root-like structures that anchor bryophytes to the substrate and facilitate absorption of water and minerals.
Mosses exhibit alternation of generations with the gametophyte (haploid) being the dominant, photosynthetic generation, while sporophyte is dependent.
