Q.NO.1. Define Morphology?
Ans: The scientific study of the structure and specific structural features of either animals or plants is called Morphology.
Q.NO.3. Define Pteridophytes?
Ans: The term Pteridophyte is derived from two words 'Pteron' meaning feather and 'phyton' meaning plant. Thus, Pteridophytes are planted with Feather-like leaves. Pteridophytes occupy the intermediate position between Bryophytes and Phanerogams (seed plants)., there are approximately 11,000 different species with the most being found in the tropics. An example of a Pteridophyte is the fern. They reproduce by releasing spores into the air.
Q.NO.6.Name the spore-producing organs in different groups of Pteridophytes?
Ans: Synangia (three fused sporangia) develop in Psilotum. The leaves which bear synangia in Tmesipteris may be murconate rather than lanceolate. Lycopodium and Equisetum bear cones containing similar spores (homosporous). Selaginella, Marsilea, Salvinia, Azolla, Regnellidium, Pilularia, Stylites, lsoetes and Platyzoma are heterosporous (produce two types of spores-microspores and megaspores. The spores are contained in sporangia which are borne on sporophylls or sporangiophores. These become aggregated into cones or strobili.
Q.NO.7. Differentiate between microphylls and megaphylls?
Ans: Microphylls: The sporophytes with small and scale-like leaves, for example, those found inEphedra.
Megaphylls: These are large and well-developed leaves, for example, those found in Cycas and Pinus. These are foliage leaves and are protected by a thin layer of cuticle or waxy layer.
Q.NO.8.What are sporophylls mention their types with example?
Ans: The special type of reproductive leaves which produce sporangium (spore-producing structure) is called sporophylls.
There are two types of sporophylls.
Microsporophyll (Produce Micro-sporangia)
Megasporophyll (Produce mega-sporangia)
Q.NO.9. Differentiate between homosporous and heterosporous plants. Give example in each case?
Ans: Homosporous Ferns: produce only one type of spore that contains both male and female parts. The resulting gametophyte is monoecious that is both antheridia and archegonia are present on the same plant. E.g.Lycopodium, Equisetum.
Heterosporous Ferns: Produce two types of spores or distinct male and female spores or microspores and megaspores. The resulting gametophyte is dioecious. Microspore germinates to form male gametophyte that bears antheridia. Megaspore germinates to form a female gametophyte that bears archegonia. E.g. Selaginella, Marselia.
Q.NO.11.What is false indusium compared with true indusium?
Ans: True indusium: A delicate membranous structure arises from the lower side and covers the sorus of sporangia. Seen in Dryopteris.
False indusium: It is formed by the curving of margins of the pinnae or leaflet that protects the marginal sorus. It originates from the upper side of the pinnae. Seen in Pteris, Adiantum etc.
Q.NO.16. Give one main difference between rhizoids and roots?
Ans: A rhizoid (such as is found on the gametophytes of bryophytes or ferns) is basically just a filament or a root-like structure that anchors the plant to the ground. Rhizoids absorb water and nutrients from the soil through the process of capillary action
A root, on the other hand, is a sophisticated structure containing many different layers including vascular tissue, playing a key role in water and nutrient uptake.
Q.NO.19.What are Medan hair ferns/why adiantum is known as Medan hair ferns?
Ans: The genus name of the maidenhair fern, Adiantum, is derived from the Greek word '' - meaning 'unwetted' - as the leaves of the fern repel water, while the species name is taken from the Latin words 'capillus' and 'Veneris', meaning 'hair of Venus', giving this plant its alternative common name, the Venus maidenhair fern. The Petiole of the leaves is shining black and brittle. Due to these characteristics, the Adiantum is also known as maiden hair fern.
Q.NO.23. what is a stele? What are the components of stele?
Ans: Stele is the central cylinder or core of vascular tissue in higher plants. The stele consists of the xylem, phloem, pericycle and medullary rays and pith if present. The term 'stele' was for the first time used by Van Tieghem and Douliot in 1886 in their stellar Theory'.
Q.NO.26.Name the different Eras of the Geological time chart?
Ans: The largest group of the Geological time chart is called Era. There are Four Eras in the Geological time chart. (i) CENOZOIC (ii) MESOZOIC (iii) PALEOZOIC
(iv) PRECAM BRAIN/PRPTEROZOIC
Q.NO.28.Differentiate between foliage leaves and scale leaves?
Ans: Scale leaves: Scaly leaves are thin, brown-coloured and scale-like and develop only on long as well as dwarf shoots, these are small undeveloped leaves which are sessile and rarely green. Their function is usually protection.
Foliage leaves: Normal leaves attached to aerial stems and branches are called foliage leaves. Foliage leaves are large, needle-like, and vary in number from 1 to 5 in different species. These are usually green-coloured. The main function of these leaves is to take part in photosynthesis, respiration and transpiration-The word 'leaf is normally used for foliage leaves.
Q.NO.29. Differentiate between ovuliferous scales and bracket scales?
Ans: Each Megasporophyll of Pinus consists of two types of scales, known as bract scales and ovuliferous scales.
Bract scales are thin, dry, membranous, brown-coloured structures having fringed upper parts. These are also called carpellary scales.
An ovuliferous scale is present on the upper surface of each bract scale. Each ovuliferous scale is woody, bigger and stouter than the bract scale and it is triangular in shape. A broad sterile structure, with a pointed tip, is present at the apex of these scales. This is called the apophysis. At the base of the upper surface of each ovuliferous scale are present two sessile and naked ovules.
Q.NO.31. What are Manoxylic wood and Pycnoxylic wood?
Ans: Manoxylic wood: The wood is porous, soft and contains more parenchyma. This type of wood is found in the members of Cycadophyta usually. It is less important commercially.
Pycnoxylic wood: It is compact and hard with narrow medullary rays. This kind of wood is more important commercially than manoxylic wood. This type of wood is found in the members of the Coniferophyta.
Q.NO.35.What is Sagopalm?
Ans: Cycas revoluta species of gymnosperm in the family Cycadaceae. The pith of the Cycas revoluta yields Sago and the fruit can be eaten being rich in proteins and soluble non nitrogenous substances. The leaves of the Sago are called palm leaves.
Sago palm is a common name for several plants which are used to produce a starchy food known as sago. It is one of several species used for the production of sago, as well as an ornamental plant.
Q.NO.37. Name two important medicines produced by gymnosperms?
Ans: Medicines produced by gymnosperms are as follows
1. Ephedrine (alkaloid) extracted from Ephedra used in treating asthma, cough, cold, bronchitis etc.
2. Tincture of is a cardiac stimulant.
3. The juice extracted from young leaves of Cycas revoluta is used for curing blood vomiting and flatulence.
4. Anti-cancerous drug called taxol, is obtained from the bark of
Q.NO.38. Differentiate between Leptosporangiate and eusporangiate ferns?
Ans: (i) Eusporangiate Type: Sporangium develops from group of superficial cells. These cells divide periclinally into primary wall layers and inner primary sporogenous cells.
(ii) Leptosporangiate Type: This type of sporangium arises from a single superficial cell. It divides transversely to form an outer and an inner cell.
Q.NO.39. Explain the term Ramenta?
Ans: A: Any of the thin brownish often fringed or laciniate scales that are borne upon the leaves or young shoots of many ferns and that consist of a single layer of cells. B: the armor of a fossil cycad stump that suggests in appearance the ramenta of existing ferns. One of the thin, chafflike scales covering the shoots or leaves of certain ferns are called Ramenta.