The mode of arrangements of sepals or petals in a floral bud is known as aestivation. Draw the various types of aestivation possible for a typical pentamerous flower.
The mode of arrangement of sepals or petals in floral bud with respect to the other members of the same whorl is known as aestivation. The main types of aestivation are valvate, twisted, imbricate and vexillary. When sepals or petals in a whorl just touch one another at the margin, without overlapping, as in Calotropis, it is said to be valvate. If one margin of the appendage overlaps that of the next one and so on as in china rose, lady's finger and cotton, it is called twisted. If the margins of sepals or petals overlap one another but not in any particular direction as in Cassia and gulmohur, the aestivation is called imbricate. –
In pea, bean and Crotolaria flowers, there are five petals, the largest (standard) overlaps the two lateral petals (wings) which in turn overlap the two smallest anterior petals (keel); this type of aestivation is known as vexillary or papilionaceous (or descending imbricate).
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.
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?
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.
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?
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:
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 _______
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?
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
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
Define the following terms:
(a) aestivation (b) placentation
(c) actinomorphic (d) zygomorphic
(e) superior ovary (f) perigynous flower (g) epipetalous stamen.
Define the term inflorescence. Explain the basis for the different types of inflorescence in flowering plants.
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?
Give two examples of roots that develop from . different parts of the angiospermic plant other than the radicle.
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.
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?
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.
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.
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?
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?
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.
A typical angiosperm flower consists of four floral parts. Give the names of the floral parts and their arrangements sequentially.
Namedhe body part modified for food storage in the following.
(a) Carrot________________
(b) Colocasia_______________
(c) Sweet potato_______________
(d) Asparagus_______________
(e) Radish_______________
(f) Potato_______________
(g) Dahlia_______________
(h) Turmeric_______________
(i) Gladiolus_______________
(j) Ginger________________
(k) Portulaca_______________
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?
Differerifiate between.
a. Bract and Bracteole
b. Pulvinus and petiole
c. Pedicel and peduncle
d. Spike and spadix
e. Stamen and staminoide
f. Pollen and pollenium
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 swampy areas like the Sunderbans in West Bengal, plants bear special kind of roots called _______
A typical angiosperm flower consists of four floral parts. Give the names of the floral parts . and their arrangements sequentially.
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.
