<span>A scientific law describes repeated observations under a given set of conditions. These laws are not too specific, and they imply a casual relationship. These laws do not explain why something occurs, they merely state that something will occur if the given conditions are met. Therefore, the formation of a scientific law is a result of repeated observations. An example is Newton's first law of motion, which gives certain conditions for an object, such as no force acting on it, and then describes what the object will do in that situation, that is, remain in motion or remain stationary.</span>
B. Cell wall and a central vacuole
The cell wall is a rigid structure that surrounds the cells and allows plants to stay upright. Animal cells are more fluid.
The central vacuole is a large region in the cell that stores nutrients and fluids. Many cells, including animal cells, contain vacuoles, but most are small, and only plant cells contain large central vacuoles.
Hope this helps!!
Answer:
Class I: Hepaticopsida ( Liverworts)
Class II: Anthocerotopsida ( Hornworts)
Class III: Bryopsida ( Mosses)
Explanation:
Bryophytes are small plants that grows in moist and shady places.They don't attain great heights because of absence of roots, vascular tissues, mechanical tissues and cuticle. They are terrestrial but require external water to complete their life cycle. Hence they are called as the" amphibians" of the animal kingdom.
Class I: Hepaticopsida or Hepaticae
- Gametophytic plant body is either thalloid or foliose. If foliose the lateral appendages are without midrib.
- Rhizoids without septa
- Each cell in the thallus contain many chloroplasts
- Sex organs are embedded in the dorsal surface
- Capsule lacks columella
- Sporophyte may be simple having only one capsule or differentiated into root, seta and capsule
- It has 4 orders: Calobryales, Jungermanniales, Spherocarpales and Marchantiales
Class 2: Anthocerotae or Anthocerotopsids:
- Gametophytic plant body is simple, thalloid;thallus dorsiventra without air chambers shows no internal differentiation of tissues
- Scales are absent in the thallus
- Each cell of the thallus possess a single large chloroplast with a pyrenoid
- Sporophyte is cylindrical only partly dependent on gametophyte for its nourishment. It is differentiated into bulbous foot and cyclindrical capsule. Seta is meristematic.
- Endotheciumforms the sterile central column in the capsule. It have ony one order Anthocerotales
Class 3: Musci or Bryopsida
- Gametophyte is differentiated into prostrate protonema and an erect gametophores
- Gametophore ids foliose, differentiated into axis and lateral appendages like leaves but without midrib.
- Rhizoids are multicellular with oblique septa
- Elaters are absent in the capsule of sporangium
- The sex organs are produced in seperate branches immersed in a group of leaves.
- It has only three orders: Bryales, Andriales and Sphagnales
Bryophytes are used as a packaging material for fragile goods, glasswares etc.Mosses are good source of animal food in rocky and snow clad areas. Decoction prepared by boiling Sphagnum in water is used for the treatment of eye disease.
Its definetly not C or D and B sounds ridiculous so its A.
