ANATOMY OF FLOWERING PLANTS
2020 MARCH
1. Choose the correct answer. Casparian strips are present in: (Score
1)
a. Dicot root
b. Dicot stem
c. Dicot leaf
d. Monocot stem
Answer:
a) Dicot root
2. Observe the figure given below:
Write any three features on mesophyll
cells from the figure.
Answer:
Mesophyll tissue is made up of parenchyma. They contain
chloroplasts. It has 2 types of cells:
· Palisade
parenchyma: It is adaxially placed.
Made up of elongated cells.
· Spongy
parenchyma: Oval or round and
loosely arranged. Situated below the palisade cells and extends to the lower
epidermis.
2019 JULY IMPROVEMENT
1. The following are the anatomical features of flowering plants. Arrange
these features in the table given below: (Score 3)
i.
Exarch xylem
ii.
Presence of
hypodermis
iii.
Palisade
parenchyma cells
iv.
Conjoint and open
vascular bundles
v.
Endodermis with
casparian strips
vi.
Large empty
bulliform cells
|
STEM |
ROOT |
LEAF |
|
|
|
|
Answer:
|
STEM |
ROOT |
LEAF |
|
· Presence of hypodermis · Conjoint and open vascular
bundles |
· Exarch xylem · Endodermis with casparian strips |
· Palisade parenchyma cells · Large empty bulliform cells |
2019 MARCH
1. Notice the three simple tissues given below.
a. Sclerenchyma
b. Parenchyma
c. Collenchyma
Identify and write
the tissue that consists of cells that are thickened at the corners. Write the function
of this tissue. (Score 3)
Answer:
c) Collenchyma
Functions:
They provide mechanical support to the growing parts such as young stem and
petiole of a leaf. The cells having chloroplasts assimilate food.
2. Observe the terms given below.
Xylem, Root hairs, Pith, Stomata,
Cambium, Bulliform cells
From this, identify
and write the structures seen in epidermal tissue system. Write their
functions. (Hint: 3 structures).
Answer:
Root hair:
Absorption of water and minerals.
Stomata:
Transpiration.
Bulliform cells: Rolling and unrolling of leaves to reduce surface area.
2018 JULY IMPROVEMENT
1. Choose the CORRECT answer. (Score
1)
All tissues on the
inner side of the endodermis together constitute.
a) Conjunctive tissue
b) Stele
c) Pericycle
d) Vascular bundle
Answer:
b) Stele
2. Observe the T.S. of a plant p given below.
Identify the plant part and explain any two (features of its vascular bundles). (Score 2)
Answer:
Dicot stem.
Features of vascular bundles:
Conjoint, open, cambium present.
2018 MARCH
1. Complete the flowchart given below. (Score 2)
Answer:
a) Secondary xylem
b)
Metaxylem
c) Exarch
d)
Stem
2. The tissue found between the upper and
lower epidermis of a leaf is called mesophyll. (Score 3)
a) Write the type of cells found in this tissue in a dicot leaf.
b) Mention two differences between a dicot leaf and monocot leaf.
Answer:
a) Palisade parenchyma and spongy parenchyma.
b)
|
Dicot leaf |
Monocot leaf |
|
Stomata on lower epidermis.
|
Stomata on both
surfaces of the epidermis. |
|
Dorsiventral leaf. |
Isobilateral leaf. |
|
Bulliform cells absent. |
Bulliform cells present. |
2017 JULY (IMPROVEMENT)
1. Parenchyma is a tissue for storage,
sclerenchyma is a tissue for ............ (Score
1)
Answer:
Mechanical support or
rigidity.
2. The following are the characters of
dicot stem and monocot stem. Identify the characters and write in appropriate column.
a) Sclerenchymatous hypodermis
b) Collenchymatous hypodermis
c) Vascular bundles are conjoint, closed
d) Vascular bundles are arranged in a ring. (Score 2)
Answer:
|
Dicot stem |
Monocot stem |
|
b) Collenchymatous hypodermis d) Vascular bundles are arranged in a ring. |
a) Sclerenchymatous hypodermis c) Vascular bundles are conjoint, closed |
2017 MARCH
1. a)
The tissues involve in secondary growth of dicot plants are vascular
cambium and ..................
b) Compare the
formation of vascular cambia in dicot stem and dicot root. (Score 3)
Answer:
a) Cork cambium
b) In
dicot stems, cells of cambium present between primary xylem & primary
phloem is intrafascicular cambium. Cells of medullary cells, adjoining
this intrafascicular cambium become meristematic and form the interfascicular
cambium. Thus, a continuous ring of cambium is formed.
In dicot root, the vascular cambium is
completely secondary in origin. It originates from the tissue located just
below the phloem bundles, a portion of pericycle tissue above the protoxylem
forming a complete and continuous wavy ring and later become circular.
2016 MARCH
1. How does periderm develop in dicot stem
and replace the outer broken cortical and epidermal layers? (Score 3)
OR
In dicot stem, both intrafascicular and
interfascicular cambium form a ring of vascular cambium. Explain the activity
of this cambial ring. (Score 3)
Answer:
Due to the
activity of vascular cambium, girth of the stem increases. This results the
breakdown of outer cortical and epidermis layers. So the new protective tissues
are formed by another meristematic tissue called cork cambium or phellogen.
Phellogen cuts off cells on both sides. The outer cells differentiate into cork
or phellem while the inner cells differentiate into secondary cortex or
phelloderm.
Phellogen,
phellem, and phelloderm are collectively known as periderm.
OR
The cambial
ring cut off new cells towards the inner (secondary xylem) and the outer sides
(secondary phloem). The cambium is more active on the inner side than on the
outer.
Amount of secondary xylem produced is more
than secondary phloem. The primary and secondary phloems get gradually crushed
due to the continued formation and accumulation of secondary xylem.
2015 SEPTEMBER (IMPROVEMENT)
1. Identify the types of vascular bundles in figure 1 & 2. Write the
features of each vascular bundle. (Hint: Any 2 points each) (Score 3)
Answer:
Fig.1: Conjoint closed.
Fig.2: Conjoint open.
- Conjoint Open type: In this, cambium is present between
phloem and xylem. So vascular bundles can form secondary xylem and phloem
tissues. Xylem & phloem are jointly situated at the same radius of vascular bundles. E.g. dicotyledonous stems.
- Conjoint Closed type: In this, cambium is absent. Hence, they do
not form secondary tissues. Xylem & phloem are jointly situated at the same radius of vascular bundles. E.g. monocotyledons.
OR
Distinguish between leaf anatomy of dicot leaf and monocot leaf. (Hint:
Any three points each)
Answer:
|
Dicot leaf |
Monocot leaf |
|
o Stomata are more in abaxial epidermis and fewer or
absent in adaxial epidermis. o Mesophyll is differentiated into palisade and spongy
parenchyma. o Bulliform cells absent. |
o Stomata are present
on both surfaces of epidermis. o Mesophyll is not
differentiated into palisade and spongy parenchyma. o Bulliform
cells present. |
2015 MARCH
1. In a dicotyledonous stem, secondary growth takes place at two regions by
the activity of two lateral meristems.
a) Identify the two
lateral meristems. (Score 1)
b) List the new tissues formed from each of these meristems. (Score 2)
Answer:
a) Vascular cambium &
cork cambium.
b) Vascular cambium → Secondary
xylem & Secondary phloem.
Cork cambium → cork (phellem) & secondary cortex (phelloderm).