Define the term inflorescence. Explain the basis for the different types of inflorescence in flowering plants.
The arrangement of flowers on the floral axis is termed as inflorescence. A flower is a modified shoot wherein internodes do not elongate and the axis gets condensed. The apex produces different kinds of floral appendages laterally at successive nodes instead of leaves. When a shoot tip transforms into a flower, it is always solitary. Depending on whether the apex gets converted into a flower or continues to grow, two major types of inflorescence are defined – racemose and cymose. In racemose type of inflorescence the main axis continues to grow, the flowers are borne laterally in an acropetal succession. In cymose type of inflorescence the main axis terminates in a flower, hence is limited in growth. The flowers are borne in a basipeta! order.
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?
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?
In swampy areas like the Sunderbans in West Bengal, plants bear special kind of roots called __________ .
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.
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 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?
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?
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?
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?
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?
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.
Tendrils of grapevines are homologous to the tendril of pumpkins but are analogous to that of pea. Justify the above statement.
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:
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.
In swampy areas like the Sunderbans in West Bengal, plants bear special kind of roots called _______
Reticulate and parallel venation are characteristic of ________ and ______ respectively.
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.
Give two examples of roots that develop from different parts of the angiospermic plant other than the radicle.
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.
Given below are a few floral formulae of some well known plants. Draw floral diagrams from these formulae.
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.
Stolon, offset and rhizome are different forms of stem modifications. How can these modified forms of stem be distinguished from each other?
How do you distinguish between hypogeal germination and epigeal germination? What is the role of cotyledon (s) and the endosperm in the germination of seeds?
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.
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
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.
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
Stolon, offset and rhizome are different forms of stem modifications. How can these modified forms of stem be distinguished from each other?
A typical angiosperm flower consists of four floral parts. Give the names of the floral parts and their arrangements sequentially.
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.
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.
