The lawn grass (Cynodon dactylon) needs to be mowed frequently to prevent its overgrowth. Which tissue is responsible for its rapid growth?
Lawn grass is a runner (stem . modification) of the Family Poaceae. It grows beautifully on the surface of the soil, thus covering entire soil surface, so it is grown for landscaping in gardens.
Meristematic tissues are responsible for rapid growth of these lawn grasses (Cynodon dactylon). The presence of apical bud in these grasses does not allow the nearby lateral buds to grow. This phenomenon is known 4s apical dominance. Therefore lawn grass needs to be moved frequently to prevent its overgrowth. When the apex of grass is cut frequently, it leads to the growth of lateral branches, that makes it more bushy.
Arrange the following in the sequence you would find them in a plant starting from the periphery—phellem, phellogen, phelloderm.
Trunks of some of the aged tree species appear to be composed of several fused trunks. Is it a physiological or anatomical abnormality? Explain in detail.
Cork cambium forms tissues that form the cork. Do you agree with this statement? Explain.
Arrange the following in the sequence you would find them in a plant starting from the periphery – phellem, phellogen, phelloderm.
The lawn grass (Cyandon dactylon) needs to be mowed frequently to prevent its overgrowth. Which tissue is responsible for its rapid growth?
Match the following and choose the correct option from below.
| A. | Meristem | (i) | Photosynthesis, storage |
| B. | Parenchyma | (ii) | Mechanical support |
| C. | Collenchyma | (iii) | Actively dividing cells |
| D. | Sclerenchyma | (iv) | Stomata |
| E. | Epidermal tissue | (v) | Sclereids |
Options:
(a) A—(i), B—(iii), C—(v), D—(ii), E—(iv)
(b) A—(iii), B—(i), C—(ii), D—(v), E—(iv)
(c) A—(ii), B—(iv), C—(v), D—(i), E—(iii)
(d) A—(v), B—(iv), C—(iii), D—(ii), E—(i)
Protoxylem is the first formed xylem. If the protoxylem lies next to phloem what kind of arrangement of xylem would you call it?
Trunks of some of the aged tree species appear to be composed of several fused trunks. Is it a physiological or anatomical abnormality? Explain in detail.
The transverse section of a plant material shows the following anatomical features – (a) the vascular bundles are conjoint, scattered and surrounded by a sclerenchymatous bundle sheath, (b) phloem parenchyma is absent. What will you identify it as?
While eating peach or pear it is usually seen that some stone like structures get entangled in the teeth, what are these stone like structures called?
Plants require water for their survival. But when watered excessively, plants die. Discuss.
Below is a list of plant fibres. From which part of the plant these are obtained?
(a) Coir
(b) Hemp
(c) Cotton
(d) Jute
Epidermal cells are often modified to perform specialised functions in plants. Name some of them and function they perform.
The cross-section of a plant material showed the following features when viewed under the microscope.
(a) The vascular bundles were radially arranged.
(b) Four xylem strands with exarch condition of protoxylem.
To which organ should it be assigned?
What part of the plant would show the following?
a. Radial vascular bundle
b. Polyarch xylem
c. Well developed pith
Each of the following terms has some anatomical significance. What do these terms mean? Explain with the help of line diagrams.
a. Plasmadesmoses/Plasmodesmata
b. Middle lamella
c. Secondary wall
Plants require waterfortheir survival. But when watered excessively, plants die. Discuss.
What is present on the surface of the leaves which helps the plant prevent loss of water but is absent in roots?
Protoxylem is the first formed xylem. If the protoxylem lies next to phloem what kind of arrangement of xylem would you call it?
Epidermal cells are often modified to perform specialized functions in plants. Name some of them and function they perform.
Cut a transverse section of young stem of a plant from your school garden and observe it under the microscope. How would you ascertain whether it is a monocot stem or a dicot stem ? Give reasons.
What are the characteristic differences found in the vascular tissue of gymnosperms and angiosperms?
The cross-section of a plant material showed the following features when viewed under the microscope.
a. The vascular bundles were radially arranged.
b. Four xylem strands with exarch condition of protoxylem.
To which organ should it be assigned?
Assume that a pencil box held in your hand, represents a plant cell. In how many possible planes can it be cut? Indicate these cuts with the help of line drawings.
Match the following and choose the correct option from below.
| A. | Cuticle | (i) | Guard cells |
| B. | Bulliform cells | (ii) | Single layer |
| C. | Stomata | (iii) | Waxy layer |
| D. | Epidermis | (iv) | Empty colourless cell |
Options:
(a) A—(iii), B—(iv), C—(i), D—(ii)
(b) A—(i), B—(ii), C—(iii), D—(iv)
(c) A—(iii), B—(ii), C—(iv), D—(i)
(d) A—(iii), B—(ii), C—(i), D—(iv)
Write the precise function of:
a. Sieve tube
b. Interfasicular cambium
c. Collenchyma
d. Aerenchyma
Product of photosynthesis is transported from the leaves to various parts of the plants and stored in some cell before being utilised. What are the cells/ tissues that store them?
The lawn grass (Cynodon dactylon) needs to be mowed frequently to prevent its overgrowth. Which tissue is responsible for its rapid growth?
Point out the differences in the anatomy of, leaf of peepal (Ficus religiosa) and maize {Zea mays). Draw the diagrams and label the differences.
Distinguish between the following:
(a) Exarch and endarch condition of protoxylem
(b) Stele and vascular bundle
(c) Protoxylem and metaxylem
(d) Interfasicular cambium and intrafasicular cambium
(e) Open and closed vascular bundles
(f) Stem hair and root hair. .
Protoxylem is the first formed xylem. If the protoxylem lies next to phloem what kind of arrangement of xylem would you call it?