How can you differentiate between free central and axile placentation?
When the ovules are borne on central axis and septa are absent, as in Dianthus and Primrose the placentation is called free central.
When the placenta is axial and the ovules are attached to it in a multilocular ovary, the placentation is said to be axile, as in China rose, tomato and lemon.
Roots obtain oxygen from air in the soil for respiration. In the absence or deficiency of 02, root growth is restricted or com pletely stopped. How do the plants growing in marshlands or swamps obtain their 02 required for root respiration?
Mango and coconut are ‘drupe’ type of fruits. In mango fleshy mesocarp is edible. What is the edible part of coconut? What does milk of tender coconut represent?
In swampy areas like the Sunderbans in West Bengal, plants bear special kind of roots called __________ .
Write the floral formula of an actinomorphic, bisexual, hypogynous flower with five united sepals, five free petals, five free stamens and two united carples with superior ovary and axile placentation.
Rhizome of ginger is like the roots of other plants that grows underground. Despite this fact ginger is a stem and not a root. Justify.
Roots obtain oxygen from air in the soil for respiration. In the absence or deficiency of 02, root growth is restricted or completely stopped. How do the plants growing in marshlands or swamps obtain their 02 required for root respiration?
Write floral formula for a flower which, is bisexual; actinoiflorphic; sepals five, twisted aestivation, petals five; valvate aestivation; stamens six; ovary tricarpellary, syncarpous, superior, trilocular with axile placentation.
Seeds of some plants germinate immediately after shedding from the plants while in other plants they require a period of rest before germination. The later phenomena is called as dormancy. Give the reasons for seed dormancy and some methods to break it.
The essential functions of roots are anchorage and absorption of water and minerals in the terrestrial plant. What functions are associated with the roots of aquatic plants? How are roots of aquatic plants and terrestrial plants different?
Tendrils are found in the following plants. Identify whether they are stem tendrils or leaf tendrils,
a.Cucumber
b. Peas
c. Pumpkins
. Grapevine
e. Watermelons
The arrangements of ovules within the ovary is known as placentation. What does the term placenta refer to? Name and draw various types of placentations in the flower as seen in T.S. or V.S.
Reticulate and parallel venation are characteristic of ________ and ______ respectively.
You have heard about several insectivorous plants that feed on insects. Nepenthes or the pitcher plant is one such example, which usually grows in shallow water or in marsh lands. What part of the plant is modified into a ‘pitcher’? How does this modification help the plant for food even though it can photosynthesise like any other green plant?
The essential functions of roots are anchorage and absorption of water and minerals in the terrestrial plant. What functions are associated with the roots of aquatic plants. How are roots of aquatic plants and terrestrial plants different?
Reticulate venation is found in dicot leaves while in monocot leaves venation is of parallel type. Biology being a ‘Science of exceptions’, find out any exception to this generalisation.
Mango and coconut are ‘drupe’ type of fruits. In mango fleshy mesocarp is edible. What is the edible part of coconut? What does milk of tender coconut represent?
Tendrils of grapevines are homologous to the tendril of pumpkins but are analogous to that of pea. Justify the above statement.
Mango and coconut are ˜drupe' type of fruits. In mango fleshy mesocarp is edible. What is the edible part of coconut? What does milk of tender coconut represent?
Given below are a few floral formulae of some well known plants. Draw floral diagrams from these formula.
Justify the following statements on the basis of external features:
(i) Underground parts of a plant are not always roots.
(ii) Flower is a modified shoot.
In Opuntia the stem is modified into a flattened green structure to perform the function of leaves (i.e., photosynthesis). Cite some other examples of modifications of plant parts for the purpose of photosynthesis.
In swampy areas like the Sunderbans in West Bengal, plants bear special kind of roots called _______
Stolon, offset and rhizome are different forms of stem modifications. How can these modified forms of stem be distinguished from each other?
Reticulate venation is found in dicot leaves while in monocot leaves venation is of parallel type. Biology being a 'Science of exceptions', find out any exception to this generalization.
Rearrange the following zones as seen in the root in vertical section and choose the correct option.
A. Root hair zone
B. Zone of meristems
C. Rootcapzone
D. Zone of maturation
E. Zone of elongation
(a) C, B, E, A, D (b) A,B,C,D,E
(c) D, E, A, C, B (d) E, D, C, B, A
In Opuntia the stem is modified into a flattened green structure to perform the function of leaves (/’.e., photosynthesis). Cite some other examples of modifications of plant parts for the purpose of photosynthesis.
Match the followings and choose the correct option.
|
Group A |
Group B | ||
|
A. |
Aleurone layer | (i) |
Without fertilization |
|
B. |
Parthenocarpic fruit | (ii) |
Nutrition |
|
C. |
Ovule | (iii) |
Double fertilization |
| D. |
Endosperm |
(iv) |
Seed |
Options:
Give two examples of roots that develop from different parts of the angiospermic plant other than the radicle.
Given below are a few floral formulae of some well known plants. Draw floral diagrams from these formulae.
Distinguish between families Fabaceae, Solanaceae, Liliaceae on the basis of gynoecium characteristics (with figures), Also write economic importance of any one of the above family.
You have heard about several insectivorous plants that feed on insects. Nepenthes or the pitcher plant is one such example, which usually grows in shallow water or in marsh lands. What part of the plant is modified into a 'pitcher'? How does this modification help the plant for food even though it can photosynthesize like any other green plant?
Write floral formula for a flower which, is bisexual; actinomorphic; sepals five, twisted aestivation, petals five; valvate aestivation; stamens six; ovary tricarpellary, syncarpous, superior, trilocular with axile placentation.
Stolon, offset and rhizome are different forms of stem modifications. How can these modified forms of stem be distinguished from each other?
Tendrils are found in the following plants. Identify whether they are stem tendrils or leaf tendrils.
(a) Cucumber
(b) Peas
(c) Pumpkins
(d) Grapevine
(e) Watermelons
