1. What is histogen theory? Ans: The Histogen theory was proposed by Hanstein. According to him there are three regions in the seed plants. They are (a) Dermatogen : which forms the epidermal region, (b) Periblem: The cortex is formed by it and (c) plerome: which helps in the formation of stelar region.
2. What is Tunica carpus theory? Ans: It was proposed by Schmidt. He described that the shoot apex is differentiated into : (a) Tunica- by which epidermis and some portion of outer cortex is formed. (b) Carpus- it forms the inner region of the cortex and stele region.
3. What are meristems? Mention the types of meristems based on their position? Ans: Meristems are a group of immature embryonic and living cells with no inter cellular spaces. Based on the position the meristems are divided into 3 types. They are - Apical meristems: present on the apical regions. - Lateral meristems: present on the sides of the stem. - Intercalary meristems: present on the both sides of the nodal region.
4. What is stomata? Ans: These are bean or kidney shaped cells present in the aerial region of the plants. They help in preventing the loss of water.
5. What are Bulli form cells? Ans: These are bulbous in structure, present in monocot leaves exactly on the vascular bundles. They help in rolling and unrolling of the leaves.
6. What is living mechanical tissue? Ans: Hypodermis is the living tissue which is present in the aerial parts of the dicots. It gives mechanical support to the young plant body.
7.What is Endodermis? Ans: The endodermis is the innermost layer of the cortex present adjacent to the pericycle and it is composed of closely packed cells.
8. What are bicollateral vascular bundles? Ans: In this condition the phloem is present on both the sides of xylem separated by cambium. The phloem is developed in this type.
9. What are concentric vascular bundles? Ans: If any one type of tissue(xylem/phloem) is surrounded by the other type is called concentric vascular bundles. These are closed type.
10. Name the important tissues present in the vascular bundles. Mention their function. Ans: There are two important tissues present in vascular bundles. They are Xylem and Phloem. Xylem helps in transporting water and minerals from the plant and Phloem transports the food materials to all the parts of the plant.
11. Distinguish normal secondary growth from anomalous secondary growth. Ans: Secondary growth is due to the cell division of cambium or secondary meristems. Any deviation from the normal secondary growth is called anomalous secondary growth.
12. Define anomalous secondary growth. Give one monocotyledonous example? Ans: Any deviation from the normal secondary growth is called anomalous secondary growth. Eg. Dracaena.
13. Mention anomalous feature in Dracaena stem. Ans: A cambial ring is formed by some parenchymatous tissue. More secondary tissue is formed below the cambial ring. The secondary vascular bundles secondary cortex are produced towards the inner side.
14.Mention anomalous feature in Boerhaavia stem. Ans: Boerhaavia shows anomalous secondary growth with the presence of vascular bundles in the medullary region with two additional vascular bundles.
15. Write the scientific name, family, and importance of teak wood, red sanders, and rose wood. Ans: Scientific name : Tectona grandis (teak wood). Family : Laminaceae Importance : Employed for sounds and musical instruments, keys etc.
Scientific name : Pterocarpus santilinus (red sander) Family : Fabaceae Importance : Useful for treating digestive tract problems, cough, fluid retentions.
Scientific name : Dalbergia sisso (rose wwod) Family : Fabaceae Importance : Useful for furniture, plywood, construction and other musical instruments etc.
16. Define embryology? Mention eminent Indian embryologist? Ans: The study of development of an embryo from the stage of ovum fertilizations through to the fetal stage is called as embryology. Panchanan Maheshwari is the eminent Indian embryologist.
17. What is microspore? Ans: Microspores develop into male gametophytes. Male gametophytes produce sperms cells which are used for fertilization with an egg and forms zygote.
18. What is Tapetum? Ans: Tapetum is the innermost layer in anther which surrounds the sporogenous tissue. It provides nourishment to the developing microspores.
19.What is Endothecium? Ans :Endothecium is second outermost layer of the wall layers of the anther, present below the epidermis. It expands radially with fibrous thickenings. ➡At maturity , the cells of endothecium loss water and contact. Thus help in dehiscence of pollen sac.
20. What is Megasporangium? Mention any two types. Ans: The female reproductive organ in plants is called as Megasporangium. • Orthotropous and Anatropous.
21. Define Nucellus, Chalaza and Micropyle. Ans: Nucellus: It is a diploid nutritive tissue which provides nourishment to the developing embryo sac. Chalaza: The portion present below the embryo sac is called Chalaza. Micropyle: It is a minute opening that is present above the ovum and synergid cells. It is useful for the entry of pollen grains into embryo sac.
22.What is embryo sac? Mention three types of embryo sac? Ans: Embryo sac is the female gametophyte of a seed. It is of three types: Monosporic, Bisporic and Tetrasporic.
23. Define Fertilization, Double fertilization and triple fusion. Ans: Fertilization: Fusion of two haploid gametes is called as Fertilization. Double fertilization: If the female gametophyte fuses with two male gametes it is called as double fertilization. Triple fusion: Triple fusion is a fusion that involves a sperms nucleus and two polar nuclei.
24.What is Ruminate endosperm? Ans: Ruminate endosperm is a condition in which the endosperm is dissected by ingrowths of the seed coat. It is seen in Palmae and Annonacae.
25.What is Endosperm? Mention the types. Ans: Endosperm is a tissue that surrounds and nourishes the embryo in the seeds of angiosperms. It is of three types: Nuclear endosperm, Cellular endosperm and Helobial endosperm.
DEFINE CONCENTRIC VASCULAR BUNDLES Concentric vascular bundles are those in which one vascular element surrounds other on all sides. It is of two types - Amphivasal and Amphicribal. When xylem surrounds the phloem tissue from all sides the vascular bundle is called as an amphivasal vascular bundle or leptocentric type- example- Dracaena
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ReplyDeleteDEAR STUDENTS,
ReplyDeleteGOOD EVENING. ALL THE STUDENTS SUBMIT YOUR ASSIGNMENTS HERE.
Durgam Vamshi.
DeleteNB - 03.
1. What is histogen theory?
Ans: The Histogen theory was proposed by Hanstein. According to him there are three regions in the seed plants. They are (a) Dermatogen : which forms the epidermal region, (b) Periblem: The cortex is formed by it and (c) plerome: which helps in the formation of stelar region.
2. What is Tunica carpus theory?
Ans: It was proposed by Schmidt. He described that the shoot apex is differentiated into : (a) Tunica- by which epidermis and some portion of outer cortex is formed. (b) Carpus- it forms the inner region of the cortex and stele region.
3. What are meristems? Mention the types of meristems based on their position?
Ans: Meristems are a group of immature embryonic and living cells with no inter cellular spaces. Based on the position the meristems are divided into 3 types. They are
- Apical meristems: present on the apical regions.
- Lateral meristems: present on the sides of the stem.
- Intercalary meristems: present on the both sides of the nodal region.
4. What is stomata?
Ans: These are bean or kidney shaped cells present in the aerial region of the plants. They help in preventing the loss of water.
5. What are Bulli form cells?
Ans: These are bulbous in structure, present in monocot leaves exactly on the vascular bundles. They help in rolling and unrolling of the leaves.
6. What is living mechanical tissue?
Ans: Hypodermis is the living tissue which is present in the aerial parts of the dicots. It gives mechanical support to the young plant body.
7.What is Endodermis?
Ans: The endodermis is the innermost layer of the cortex present adjacent to the pericycle and it is composed of closely packed cells.
8. What are bicollateral vascular bundles?
Ans: In this condition the phloem is present on both the sides of xylem separated by cambium. The phloem is developed in this type.
9. What are concentric vascular bundles?
Ans: If any one type of tissue(xylem/phloem) is surrounded by the other type is called concentric vascular bundles. These are closed type.
10. Name the important tissues present in the vascular bundles. Mention their function.
Ans: There are two important tissues present in vascular bundles. They are Xylem and Phloem. Xylem helps in transporting water and minerals from the plant and Phloem transports the food materials to all the parts of the plant.
11. Distinguish normal secondary growth from anomalous secondary growth.
Ans: Secondary growth is due to the cell division of cambium or secondary meristems.
Any deviation from the normal secondary growth is called anomalous secondary growth.
12. Define anomalous secondary growth. Give one monocotyledonous example?
Ans: Any deviation from the normal secondary growth is called anomalous secondary growth. Eg. Dracaena.
Durgam Vamshi.
DeleteNB-03.
13. Mention anomalous feature in Dracaena stem.
Ans: A cambial ring is formed by some parenchymatous tissue. More secondary tissue is formed below the cambial ring. The secondary vascular bundles secondary cortex are produced towards the inner side.
14.Mention anomalous feature in Boerhaavia stem.
Ans: Boerhaavia shows anomalous secondary growth with the presence of vascular bundles in the medullary region with two additional vascular bundles.
15. Write the scientific name, family, and importance of teak wood, red sanders, and rose wood.
Ans: Scientific name : Tectona grandis (teak wood).
Family : Laminaceae
Importance : Employed for sounds and musical instruments, keys etc.
Scientific name : Pterocarpus santilinus (red sander)
Family : Fabaceae
Importance : Useful for treating digestive tract problems, cough, fluid retentions.
Scientific name : Dalbergia sisso (rose wwod)
Family : Fabaceae
Importance : Useful for furniture, plywood, construction and other musical instruments etc.
16. Define embryology? Mention eminent Indian embryologist?
Ans: The study of development of an embryo from the stage of ovum fertilizations through to the fetal stage is called as embryology. Panchanan Maheshwari is the eminent Indian embryologist.
17. What is microspore?
Ans: Microspores develop into male gametophytes. Male gametophytes produce sperms cells which are used for fertilization with an egg and forms zygote.
18. What is Tapetum?
Ans: Tapetum is the innermost layer in anther which surrounds the sporogenous tissue. It provides nourishment to the developing microspores.
19.What is Endothecium?
Ans :Endothecium is second outermost layer of the wall layers of the anther, present below the epidermis. It expands radially with fibrous thickenings.
➡At maturity , the cells of endothecium loss water and contact. Thus help in dehiscence of pollen sac.
20. What is Megasporangium? Mention any two types.
Ans: The female reproductive organ in plants is called as Megasporangium.
• Orthotropous and Anatropous.
21. Define Nucellus, Chalaza and Micropyle.
Ans: Nucellus: It is a diploid nutritive tissue which provides nourishment to the developing embryo sac.
Chalaza: The portion present below the embryo sac is called Chalaza.
Micropyle: It is a minute opening that is present above the ovum and synergid cells. It is useful for the entry of pollen grains into embryo sac.
22.What is embryo sac? Mention three types of embryo sac?
Ans: Embryo sac is the female gametophyte of a seed. It is of three types:
Monosporic, Bisporic and Tetrasporic.
23. Define Fertilization, Double fertilization and triple fusion.
Ans: Fertilization: Fusion of two haploid gametes is called as Fertilization.
Double fertilization: If the female gametophyte fuses with two male gametes it is called as double fertilization.
Triple fusion: Triple fusion is a fusion that involves a sperms nucleus and two polar nuclei.
24.What is Ruminate endosperm?
Ans: Ruminate endosperm is a condition in which the endosperm is dissected by ingrowths of the seed coat. It is seen in Palmae and Annonacae.
25.What is Endosperm? Mention the types.
Ans: Endosperm is a tissue that surrounds and nourishes the embryo in the seeds of angiosperms. It is of three types: Nuclear endosperm, Cellular endosperm and Helobial endosperm.
DEFINE CONCENTRIC VASCULAR BUNDLES
ReplyDeleteConcentric vascular bundles are those in which one vascular element surrounds other on all sides. It is of two types - Amphivasal and Amphicribal. When xylem surrounds the phloem tissue from all sides the vascular bundle is called as an amphivasal vascular bundle or leptocentric type- example- Dracaena