Concept explainers
Videos
What is a sieve-tube element?
a. the sugar-conducting cell found in phloem
b. the widened, perforation-containing, water-conducting cell found only in
c. the nutrient- and water-absorbing cell found in root hairs
d. the nucleated and organelle-rich support cell found in phloem
Introduction:
The plants consist of two important tissues, namely, phloem and xylem. Phloem is responsible for the transfer of organic molecules across different cells in the plants. Sieve-tube cells are the specialized cells that are present in the phloem tissue for the transport of carbohydrates.
Answer to Problem 1TYK
Correct answer:
The sieve-tube cells or the sieve-tube elements are the dead, elongated cells found in the phloem of the angiosperms. These elements carry out the transfer of sugar in the plants.
Explanation of Solution
Explanation/Justification for the correct answer:
Option (a) is given as the cell that is responsible for the conduction of sugars. The sieve-tube elements are the specialized cells involved in the conduction of the sugars in the plants. Carbohydrate (starch) is one such form of sugar. On maturity, they are considered as dead cells due to lack of nucleus. These cells are present in the phloem of the angiosperms. Hence, Option (a) is correct.
Explanation for incorrect answer:
Option (b) is given as the widened, perforation-containing, water-conducting cell found only in angiosperms. The perforation-containing, widened cells that carry out transport of water are known as xylem. So, it is a wrong answer.
Option (c) is given as cells that are found in the root hairs and are responsible for the absorption of water and nutrients. The roots hairs are also known as trichoblasts. The trichoblast is formed from the epidermis layer of the root of the plant. So, it is a wrong answer.
Option (d) is given as the nucleated and organelle-rich cells found in phloem. The nucleated and organelle-rich support cells in the phloem are also known as companion cells. The companion cells are those that transport the sugar to the sieve-tube elements in the leaves from the mesophyll. So, it is a wrong answer.
Hence, options (b), (c), and (d) are incorrect.
Thus, sieve–tube cells represent the class of cells that are specialized for the transportation of sugar in the plants and are found in the phloem.
Want to see more full solutions like this?
Chapter 34 Solutions
Biological Science (6th Edition)
- How are compound leaves distinguished from simple leaves?a. Compound leaves do not have axillary buds at the baseof leaflets.b. Compound leaves are smaller than simple leaves.c. Simple leaves are usually deciduous.d. Compound leaves are found only on pine trees.e. Simple leaves are found only in gymnosperms.arrow_forwardWhich tissue produces a structure that occurs in a concentric ring in eudicot stems, but scattered in monocot stems? Select one: O a. Vascular tissue bi Dermal tissue O c. Ground tissue d. Pareynchyma tissue O e. Seed tissuearrow_forwardWhat is the function of the lenticels? Do all stems have lenticels? How can you differentiate a monocot plant from a dicot plant just by looking at the stem? What advantage would herbaceous stems have over woody stems?arrow_forward
- Choose the incorrect statement: a. Fusiform and ray initials are formed by the vascular cambium. b. The cork cambium produces the periderm layer, a thicker tougher outer layer that replaces the epidermis. c. Wood is composed of secondary xylem. d. The vascular cambium separates the xylem on the outside of the stem and the phloem on the inside.arrow_forwardWhich of the following cell types forms most of the inside of a plant? a. meristem cells b. collenchyma cells c. sclerenchyma cells d. parenchyma cellsarrow_forwardwhich is common among a taproot system, circular arrangement of the vascular tissues, netted leaf veins, and a flower whose petals are in the multiples of four or five? a. Those are present to both monocotyledonous and dicotyledonous plant. b. Those are the external anatomy of an angiosperm. c. They are the distinguishing characterictics of a dicotyledonous plant d. Those are the main features of a monocotyledonous plant.arrow_forward
- If you were examining a cross section of a primary root of a flowering plant, how would you determine whether it was a eudicot or a monocot?arrow_forwardWhich of the following statements is false? a. Auxin and gibberellin promote stem elongation b. Cytokinin promotes cell division in shoot tips c. Abscisic acid promotes water loss and dormancy d. Ethylene promotes fruit ripening and abscission.arrow_forwardVegetative propagation in liverworts is possible because of propagules known as gemmae. Select one: True False Where would you most likely find the megasporangium of an angiosperm? a. Within an ovule contained within an ovary of a flower b. In the style of a flower c. Enclosed in the stigma of a flower d. Packed into pollen sacs within the anthers found on a stamen Which of the following plant structures is NOT matched correctly to its function? a. Stomata allow gas transfer b. Tracheids allow the movement of water and minerals c. Cuticle prevents desiccation d. Plasmodesmata - form a supportive meshwork which acts as a cellular exoskeletonarrow_forward
- Unlike eudicots, monocots have a. woody tissue.b. two seed leaves.c. scattered vascular bundles in their stems.d. flower parts in multiples of four or five.arrow_forwardIn plants, match the substances that the vascular tissues, xylem and phloem, each transport. 1. Phloem 2. Xylem 3. Xylem A. Water b. Sucrose c. Nutrientsarrow_forwardWhich of the following adaptations allowed plants to grow in drier environment but without much water loss form its tissue? O A. Plant meristem tissue B. Plant alkaloids OC. Plant cuticle O D. Plant flavonoidsarrow_forward
Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning