Description : The chief water conducting elements of xylem in gymnosperms are (a) vessels (b) fibres (c) transfusion tissue (d) tracheids
Last Answer : d) tracheids.
Description : Gymnosperms are also called soft wood spermatophytes because they lack (a) cambium (b) phloem fibres (c) thick-walled tracheids(d) xylem fibres
Last Answer : (d) xylem fibres.
Description : Gymnosperms are also called soft wood spermatophytes because they lack (1) Xylem fibres (2) Cambium (3) Phloem fibres (4) Thick-walled tracheids
Last Answer : (4) Thick-walled tracheids
Description : Transport of food material in higher plants takes place through (a) companion cells (b) transfusion tissue (c) tracheids (d) sieve elements.
Last Answer : (d) sieve elements.
Last Answer : d) sieve elements.
Description : What are xylem vessels and tracheids?
Last Answer : Xylem vessels consist of series of elongated dead cells joined together forming end to end tube like structure for conduction of water and salts
Description : An organised and differentiated cellular structure having cytoplasm but no nucleus is (a) vessels (b) xylem parenchyma (c) sieve tubes (d) tracheids.
Last Answer : (c) sieve tubes
Description : Heartwood differs from sapwood in (a) presence of rays and fibres (b) absence of vessels and parenchyma (c) having dead and non-conducting elements (d) being susceptible to pests and pathogens.
Last Answer : (c) having dead and non-conducting elements
Description : What tissue present in leaves of Pinus conducts food and water laterally? (a) Transfusion tissue (b) Phloem (c) Xylem (d) Medullary rays
Last Answer : Ans. ((a))
Description : Liverworts and mosses are characterized by their lack of vascular conducting tissue. These two groups of plants, liverwort and mosses, are known by which of the following terms: a) thallophytes (pron: THAL-o-fights) ... (pron: JIM-na-sperms) c) bryophytes (pron: BRIE-o-fights) d) none of the above
Last Answer : ANSWER: C -- BRYOPHYTES
Description : The food conducting tissue of a plant is (1) Phloem (2) Xylem (3) Parenchyma (4) Collenchyma
Last Answer : (1) Phloem Explanation: In vascular plants, phloem is the living tissue that carries organic nutrients, in particular, sucrose, a sugar, to all parts of the plant where needed. ... mainly with the transport of soluble organic material made during photosynthesis. This is called translocation.
Last Answer : Phloem
Description : The xylem vessels of plants are part of which tissue ?
Last Answer : The xylem vessels of plants are part of the complex tissue.
Description : Conifers differ from grasses in the (a) formation of endosperm before fertilization (b) production of seeds from ovules (c) lack of xylem tracheids (d) absence of pollen tubes.
Last Answer : (a) formation of endosperm before fertilization
Description : Tyloses are: (a) Lactiferous channels (b) Secretory cells (c) Sieve plates (d) Tracheal plugs plugging the lumen of vessels and tracheids
Last Answer : Ans. ((d))
Description : Which of the following statements is true? (a) Vessels are multicellular with wide lumen. (b) Tracheids are multicellular with narrow lumen. (c) Vessels are unicellular with narrow lumen. (d) Tracheids are unicellular with wide lumen.
Last Answer : (a) Vessels are multicellular with wide lumen
Last Answer : (a) Vessels are multicellular with wide lumen.
Description : Why tracheids are less efficient than vessels in conduction
Last Answer : Ans: Tracheids do not have uniform diameter, overlapped on each other at the ends and have solid cross walls. Vessels have uniform diameter, perforated cross walls and their elements are not overlapped but arranged one above the other.
Description : $ The blood vessels called arteries have thick walls. ! Blood transfusion should not be done without testing the blood group and Rh factor.
Last Answer : $ The blood vessels called arteries have thick walls. ! Blood transfusion should not be done without testing ... wrong D. If both As and R are wrong.
Description : 2. How many types of elements together make up the xylem tissue? Name them. -Science
Last Answer : The xylem tissue is made up of four main elements, namely: ➢ Vessels ➢ Tracheids ➢ Xylem fibres ➢ Xylem parenchyma
Description : List the cellular elements of xylem tissue?
Last Answer : Xylem tracheids 2. Xylem tracheae or vessels 3. Xylem fibers and 4. Xylem parenchyma
Description : Vessels are found in (a) all angiosperms and some gymnosperm (b) most of angiosperms and few gymnosperms (c) all angiosperms, all gymnosperms and some pteridophyta (d) all pteridophyta.
Last Answer : (b) most of angiosperms and few gymnosperms
Description : Why are Xylem and Phloem known as conducting tissues?
Last Answer : Because both of them help in conduction of water, mineral and food.
Description : Why are Xylem and Phloem are called vascular or conducting tissues?
Last Answer : Since both xylem and phloem tissues transport materials, they are together called vascular tissues.
Description : What is the function of xylem fibres. -Biology
Last Answer : The xylem is the vascular tissue responsible for the upward conduction of water and nutrients from the roots. The xylem tissue moves water and nutrients to various parts of the plant such as shoots and leaves. Its major components include xylem parenchyma, xylem fibers, tracheids, and xylem vessels
Description : Leptome is used for: (a) Phloem (c) Fibres (b) Xylem (d) Parenhyma
Description : Xylem fibres are made up of – (1) Scierenchyma cells with thin walls (2) Scierenchyma cells with thick walls (3) Parenchyma cells with thin walls (4) Scierenchyma cells with no obliteration in central lumen
Last Answer : (2) Scierenchyma cells with thick walls Explanation: Fibre that occurs as element of Xylem is called Xylem fibre. It is also referred to as Xylary fibre and wood fibre. It is made up of Scierenchyma cells with thick walls.
Description : A column of water within xylem vessels of tall trees does not break under its weight because of (a) lignification of xylem vessels (b) positive root pressure (c) dissolved sugars in water (d) tensile strength of water.
Last Answer : (d) tensile strength of water.
Description : The following are true about the autonomic nervous system: a. the preganglionic fibres are mainly myelinated, slow conducting B fibres b. the postganglionic fibres are mainly unmyelinated C fibres c. all preganglionic neurones are cholinergic neurons d. all above
Last Answer : all above
Description : Why are vessel elements better than tracheids? -Biology
Last Answer : answer:
Description : Tracheids differ from other tracheary elements in (a) having Casparian strips (b) being imperforate (c) lacking nucleus (d) being lignified.
Last Answer : (b) being imperforate
Description : Tracheids differ from other tracheary elements in (a) having Casparian strips (b) being imperforate (c) lacking nucleus (d) being lignified
Description : The balloon-shaped structures called tyloses (a) originate in the lumen of vessels (b) characterise the sapwood (c) are extensions of xylem parenchyma cells into vessels (d) are linked to the ascent of sap through xylem vessels.
Last Answer : (c) are extensions of xylem parenchyma cells into vessels
Description : Vascular bundles in monocotyledons are considered closed because (a) there are no vessels with perforations (b) xylem is surrounded all around by phloem (c) a bundle sheath surrounds each bundle (d) cambium is absent.
Last Answer : (d) cambium is absent.
Description : Which of the following plant cells will show totipotency? (a) Sieve tubes (b) Xylem vessels (c) Meristem (d) Cork cells
Last Answer : (c) Meristem
Description : Wood without xylem vessels are called as
Last Answer : Wood without xylem vessels are called as – Soft wood
Description : Name a gymnosperm with vessels in the Xylem.
Last Answer : Ans: Gnetum.
Description : Choose the correct statement about the action of nitrates on coronary vessels (a) They mitigate angina pectoris by increasing total coronary flow (b) They preferentially dilate conducting ... the larger arteries (d) They increase subepicardial blood flow without affecting subendocardial blood flow
Last Answer : Ans: B
Description : Choose the correct statement about the action of nitrates on coronary vessels: A. They mitigate angina pectoris by increasing total coronary flow B. They preferentially dilate conducting ... the larger arteries D. They increase subepicardial blood flow without affecting subendocardial blood flow
Last Answer : B. They preferentially dilate conducting arteries without affecting resistance arterioles
Description : Immediate allergy reaction (type I allergic reaction) is: a) An allergic or immune response that begins within a period lasting from a few minutes to about an hour after exposure to an ... cause tissue damage e) It occurs during blood transfusion reactions and in hemolytic disease of the newborn.
Last Answer : Ans: A
Description : The cells which are closely associated and interacting with guard cells are - (1) Transfusion tissue (2) Complementary cells (3) Subsidiary cells (4) Hypodermal cells
Last Answer : (3) Subsidiary cells Explanation: Guard cells interact physiologically and mechanically with subsidiary cells. Guard cells are those which have chloroplasts and control the opening of stomata. But, subsidiary cells are those which support the guard cells and they do not have chloroplasts.
Description : Transfusion tissue is present in the leaves of (a) Pinus (b) Dryopteris (c) Cycas (d) both (a) and (c).
Last Answer : (d) both (a) and (c).
Description : The cells which are colsely associated and interacting with guard cells are (1) Transfusion tissue (2) Complementary cells (3) Subsidiary cells (4) Hypodermal cells
Last Answer : Subsidiary cells
Description : In which of the following would you place the plants having vascular tissue lacking seeds? (a) Pteridophytes (b) Gymnosperms (c) Algae (d) Bryophytes
Last Answer : (a) Pteridophytes
Description : Cellulose is the chief constituent of – (1) cell wall (2) cell membrane (3) secondary wall of xylem (4) body wall of insects
Last Answer : (1) cell wall Explanation: In the primary (growing) plant cell wall, the major carbohydrates are cellulose, hemicellulose and pectin. The cell wall in plants provides the most significant difference ... is rigid (up to many micrometers in thickness) and gives plant cells a much defined shape.
Description : Cellulose is the chief constituent of (1) cell wall (2) cell membrane (3) secondary wall of xylem (4) body wall of insects
Last Answer : cell wall