Which of the following is a modified stem for the protection of plants from browsing animals?
Tendrils
Thorns
Rhizome
Tuber
Correct Answer :
B. Thorns
Thorn is a stiff, sharp-pointed woody projection on the stem or other part of a plant. Thorns are found in many plants such as Citrus, Bougainvillea. They protect plants from grazing animals.
Related Questions
Which is not a stem modification ?
Rhizome of ginger
Corm of Colocasia
Pitcher of Nepenthes
Tuber of potato
Which of the following is correct with reference to floral character of family solanaceae?
Racemose, zygomorphic, unisexual, floral characters
Racemose, zygomorphic, bisexual, polypetalous
Axillary, bisexual, actinomorphic, epipetalous
Axillary, actinomorphic, bisexual, epipetalous
In flower (X), the gynoecium occupies the highest position while the other parts are situated below it. The ovary in such flowers is said to be Y. Identify X and Y and select the correct option.
X - Epigynous, Y - Inferior
X - Perigynous, Y - Superior
X - Hypogynous, Y - Superior
X - Perigynous, Y - Half-inferior
Match the column-I containing types of aestivation with their examples given in column-II and choose the correct option.
| Column - I | Column-II |
|---|---|
| (Type of aestivation) | (Examples) |
| A. Valvate | I. Cotton |
| B. Twisted | II. Calotropis |
| C. Imbricate | III. Bean |
| D. Vexillary | IV. Gulmohar |
A I; B II; C IV; D III
A II; B I; C IV; D III
A II; B IV; C I; D III
A II; B I; C III; D IV
The part of the root which is most active in water absorption is called
root cap
maturation zone
meristematic zone
zone of elongation
Pollen grains are produced within _________of stamen.
ovary
anther
filament
connective
Match column I with column II and choose the correct option.
| Column-I | Column-II |
|---|---|
| A. Bud in the | I. Pitcher plant axil of leaf and venus fly trap |
| B. Outer layer of | II. Cacti seed coat |
| C. Spines | III. Testa (modified leaves) |
| D. Leaves modified | IV. Simple leaf to catch insects |
| E. Fleshy leaves | V. Garlic and onion with stored food |
A I, B II, C III, D IV, E V
A V, B IV, C III, D II, E I
A IV, B III, C II, D I, E V
A IV, B II, C III, D I, E V
It is a proteinous layer and the outer covering of endosperm which separates the embryo. Identify the layer.
Tegmen
Scutellum
Hyaline layer
Aleurone layer
Study the following statements and select the correct option
- Buds are present in axil of leaflets of the compound leaf.
- Pulvinus leaf-base is present in some leguminous plants.
- In Alstonia, the petioles expand, become green and synthesize food.
- Opposite phyllotaxy is seen in guava.
(ii) and (iv) are correct but (i) and (iii) are incorrect.
(i) and (iii) are correct but (ii) and (iv) are incorrect.
(i) and (iv) are correct but (ii) and (iii) are incorrect.
(ii), (iii) and (iv) are correct but (i) is incorrect.
The primary roots and its branches constitute the
fibrous root system.
tap root system.
adventitious root system.
all of the above
Which of the following part elongates directly and leads to the formation of primary roots?
bud
radicle
plumule
root hair
Pneumatophores are found in
the vegetation which is found in marshy and saline lake.
the vegetation which found in saline soil.
xerophytic condition.
hydrophytic condition.
Which one of the following characteristics is not related to gynoecium?
It is the female reproductive part of the flower.
It is composed of stamens.
Stigma is usually at the tip of the style and is the receptive surface for pollen grains.
Each ovary bears one or more ovules attached to a flattened, cushion like placenta.
The given figure (A, B, and C) shows different types of roots. Identify the root which is seen in wheat plant and originate from the base of the stem?
A
B
C
Both A and B
The given figure shows the region of root tips with their region marked as A, B and C. Choose the option which shows the correct labelling of A, B and C.
A - Zone of elongation, B - Zone of meiosis, C - Zone of mitosis.
A - Zone of maturation, B - Zone of meristematic activity, C - Zone of elongation.
A - Zone of mitosis, B - Zone of elongation, C - Zone of root cap.
A - Region of maturation, B - Region of elongation, C - Zone of meristematic activity.
The region of the root-tip whose cells undergo rapid elongation and enlargement and are responsible for the growth of the root in length is called the
region of maturation.
region of elongation.
region of meristematic activity.
root-hairs.
Which of the following statement(s) is/are correct about venation?
(i) The arrangement of veins and the veinlets in the lamina of leaf is called venation.
(ii) Reticulate venation is the characteristic of monocots.
(iii) When the veinlets form a network, the venation is termed as reticulate venation.
(iv) When the veins run parallel to each other, within a lamina, the venation is termed as parallel venation.
Only (i)
Both (i) and (ii)
(i), (iii) and (iv)
All of these
The flower is the reproductive unit in the ___________ meant for ___________ reproduction.
angiosperms and sexual
gymnosperms and sexual
algae and asexual
pteridophytes and asexual
Cotyledons and testa respectively are edible parts in which of the following group?
walnut and tamarind
cashew nut and litchi
french bean and coconut
groundnut and pomegranate
Read the following statements and answer the question.
- It is the pattern of arrangement of leaves on the stem or branch.
- It is usually of three types - alternate, opposite and whorled.
- It is meant for getting maximum amount of light. statements?
Phyllotaxy
Venation
Inflorescencew
Aestivation
Fibrous root system is found in
monocotyledonous plants.
dicotyledonous plants.
bryophytes.
gymnosperms.
Which one of the following characteristics does not belong to parietal placentation?
Ovules are borne on central axis.
Ovary is one-chambered but it becomes two-chambered due to the formation of false septum.
Examples are mustard and Argemone.
Both (b) and (c)
Which of the following represents the floral characters of liliaceae?
Six tepals, zygomorphic, six stamens, bilocular ovary, axile placentation.
Actinomorphic, polyphyllous, unilocular ovary, axile placentation.
Tricorpellary, actinomorphic, polyandrous, superior ovary, axile placentation.
Bisexual, zygomorphic, gamophyllous, inferior ovary, marginal placentation.
Which type of function is performed by the fleshy leaves of onion and garlic?
Storage
Reproduction
Photosynthesis
Protection
Read the following statements and answer the questions.
- Gynoecium is situated in the centre and other parts of the flower are located on the rim of the thalamus almost at the same level.
- Ovary is half-inferior.
- Examples are plum, rose and peach.
Which condition of flowers is being described by the above statements ?
hypogyny
perigyny
epigyny
none of these
When a flower has both androecium and gynoecium, it is known as__________.
asexual
bisexual
unisexual
multisexual
Which of the following statement(s) is/are correct about the fruit?
- Fruit is a mature or ripened ovary, developed before fertilization.
- It consists of a wall or pericarp and seeds.
- When pericarp is thick and fleshy, it is differentiated into outer mesocarp, middle epicarp and the inner endocarp.
- In mango and coconut, the fruit is known as a berry.
Only (i)
Both (ii) and (iii)
Only (ii)
All of these
Fibrous roots develop in maize from
upper nodes
lower nodes
upper internodes
none of these
A - Which one of the option shows the correct labelling of the parts marked as A, B, C and D in a typical structure of dicotyledonous seeds ?
A - Hilum, B - Micropyle, C - Radicle, D - Cotyledon, E - Plumule
A - Hilum, B - Micropyle, C - Plumule, D - Cotyledon, E - Radicle
A - Micropyle, B - Hilum, C - Plumule, D - Cotyledon, E - Radicle
A - Hilum, B - Micropyle, C - Plumule, D - Radicle, E - Cotyledon
Most prominent function of inflorescence is
dispersal of seeds.
formation of more fruits.
formation of pollen grains.
dispersal of pollens.