Board: CBSE Standard: 12th Subject: Biology Test Name: PA 1
Student Name:__________________ Section:________ Roll No.:__________
Time: 45 Minutes Marks: 70
Attempt all questions.
1: Read the following passage and answer the questions on the basis of the same:
Gynoecium, is the female reproductive part of the flower. It may consist of a single or more than one
pistil. These pistil may be free or fuse. Each pistils has three parts, stigma, style and ovary. Ovary has
an ovarian cavity, which has one or many chambers or locules. The placenta is located inside the
ovarian cavity. Megasporangia or ovule arise from the placenta.
In which of the following plants the number of ovules in an ovary is one ?
Mango Orchids
Water melon Papaya
2: Read the following passage and answer the questions on the basis of the same:
Gynoecium, is the female reproductive part of the flower. It may consist of a single or more than one
pistil. These pistil may be free or fuse. Each pistils has three parts, stigma, style and ovary. Ovary has
an ovarian cavity, which has one or many chambers or locules. The placenta is located inside the
ovarian cavity. Megasporangia or ovule arise from the placenta.
A multicarpellary, syncarpous gynoecium is found in :
Papaver Brinjal
Tomato All of these
3: Read the following passage and answer the questions on the basis of the same:
Gynoecium, is the female reproductive part of the flower. It may consist of a single or more than one
pistil. These pistil may be free or fuse. Each pistils has three parts, stigma, style and ovary. Ovary has
an ovarian cavity, which has one or many chambers or locules. The placenta is located inside the
ovarian cavity. Megasporangia or ovule arise from the placenta.
82% of ovules found in angiosperms are ............. .
Anatropous Amphitropous
Orthotropous Circinotropous
4: Read the following passage and answer the questions on the basis of the same:
Gynoecium, is the female reproductive part of the flower. It may consist of a single or more than one
pistil. These pistil may be free or fuse. Each pistils has three parts, stigma, style and ovary. Ovary has
an ovarian cavity, which has one or many chambers or locules. The placenta is located inside the
ovarian cavity. Megasporangia or ovule arise from the placenta.
Which among the following cell is binucleate in an embryo sac ?
Antipodal cell Central cell
Synergid Female gamete
5: Read the following passage and answer the questions on the basis of the same:
Gynoecium, is the female reproductive part of the flower. It may consist of a single or more than one
pistil. These pistil may be free or fuse. Each pistils has three parts, stigma, style and ovary. Ovary has
an ovarian cavity, which has one or many chambers or locules. The placenta is located inside the
ovarian cavity. Megasporangia or ovule arise from the placenta.
Flowers with both androecium and gynoecium are called :
Anther Bisexual flowers
Unisexual flowers Androgynous
6: How many cells are present in the pollen grains at the time of their release from anther? Name the cells.
7: "Pollen grains in wheat are shed at the 3-celled stage while in peas they are shed at the 2-celled stage.”
Explain. Where are germ pores present in a pollen grain?
8: A pollen grain in angiosperm at the time of dehiscence from an anther could be 2-celled or 3-celled.
Explain. How are the cells placed within the pollen grain when shed at a 2-celled stage?
9: In a flowering plant, a microspore mother cell produces four male gametophytes while a megaspore
mother cell form only one female gametophyte. Explain.
10: Mention the ploidy of the different types of cells present in the female gametophyte of an angiosperm.
11: Angiosperm bearing unisexual flowers are said to be either monoecious or dioecious. Explain with the
help of one example each.
12: When and where do tapetum and synergids develop in flowering plants? Mention their functions.
13: Where are the following structures present in a male gametophyte of an angiosperm? Mention
the function of each one of them.
(a) Germ pore
(b) Sporopollenin
(c) Generative cell
14: Pollen banks are playing a very important role in promoting plant breeding programme the world over.
How are pollens preserved in the pollen banks? Explain. How are such banks benefiting our farmer?
Write any two ways.
15: (i) Do all pollen grains remain viable for the same length of time? Support your answer with
two suitable examples.
(ii) How are pollen grains stored in pollen banks? State the purpose of storing pollen grains in banks.
16: (i) Draw a labelled diagram of a section of an enlarged view of microsporangium of an angiosperm.
(ii) Name the cells and the event they undergo to produce pollen grains.
17: (i) Draw a labelled sketch of a mature 7-celled, 8-nucleate embryo sac.
(ii) Which one of the cells in an embryo-sac produce endosperm after double fertilisation?
OR
A mature embryo-sac in a flowering plant may possess 7-cells, but 8-nuclei. Explain with the help of a
diagram only.
18: (a) Name the organic material through which exine of the pollen grain is made up of. How is this
material advantageous to pollen grain?
(b) Still it is observed that it does not form a continuous layer around the pollen grain. Give reason.
(c) How are ‘pollen banks’ useful?
19: How many meiotic divisions are required to produce 76 seeds in a Guava fruit?
20: How many pollen grains and ovules are likely to be formed in the anther and the ovary of
an angiosperm bearing 25 microspore mother cells and 25 megaspore mother cells respectively?
21: Name and explain the technique that can be used in developing improved crop varieties in
plants bearing female flowers only.
22: Explain the process of pollination in Vallisneria
23: You are conducting artificial hybridisation on papaya and potato. Which one of them would require the
step of emasculation and why?
However, for both, you will use the process of bagging. Justify giving one reason.
24: Draw a well-labelled diagram of L.S of a pistil of a flower showing the passage of growing of
pollen tube up to its destination.
25: Explain double fertilisation in an angiosperm.
26: Explain three different modes of pollination that can occur in a chasmogamous flower.
27: How does a bisexual flowering plant ensures cross pollination? Explain.
28: (a) Differentiate between geitonogamy and xenogamy.
(b) Write the difference in the characteristics of the progeny produced as a result of the two processes.
29: Write one advantage and one disadvantage of cleistogamy to flowering plants.
30: Which one of the cell in an embryo-sac produce endosperm after double fertilisation?
31: These pictures show the gynoecium of
(i) Papaver and
(ii) Michellia flowers. Write the difference in the structure of their ovaries.
32: If the stamens are well exposed usually which mode of pollination the plant is expected to follow ?
33: It is said apomixis is a type of asexual reproduction. Justify.
34: “For a common man both mango and strawberry are fruits, but not for a biology students”. Justify.
35: Name a distinguishing structure seen in a mature black pepper seed and not in a pea seed. State
how does it develop.
36: (a) You are given castor and bean seeds. Which one of the two would you select to observe
the endosperm?
(b) The development of endosperm precedes that of embryo in plants. Justify.
37: "Apomixis is a form of asexual reproduction that mimics sexual reproduction in plants”. Explain with
the help of a suitable example.
38: If the meiocyte of a maize plant contains 20 chromosomes, write the number of chromosomes in the
endosperm and embryo of the maize grain and give reasons in support of your answer.
39: Do you think apomixis can be compared with asexual reproduction? Support your answer, giving one
reason. How is apomixis beneficial to farmers? Explain.
40: Differentiate between parthenocarpy and parthenogenesis. Give one example of each.
41: Parthenocarpy and apomixis have been observed in some plants. Give an example of each. State
a similarity and a difference observed between the two processes.
42: (a) Trace the development of an endosperm after fertilisation with reference to coconut. Mention the
importance of endosperm development.
(b) Write the importance of ‘pollen bank’.
43: Identify ‘A’ in the figure showing a stage of embryo development in a dicot plant and mention its
function.
44: Name the type of fruit apple is categorised under and why? Mention two other examples which belong
to the same category as apple.
45: Given below is a section of a Maize grain. Identify ‘A’ and state its function.
46: (a) Explain any two ways by which apomictic seed can develop.
(b) List one advantage and one disadvantage of a apomictic crop.
(c) Why do farmers find production of hybrid seeds costly?
47: (a) Explain the process of double fertilisation in angiosperms.
(b) Why does the development of endosperm precedes that of embryo?
(c) List the parts of a typical dicot embryo.
48: (a) A capsicum flower has 240 ovules in its ovary. But, it produces a fruit with only 180 viable seeds.
Explain giving a reason that could be responsible for such a result.
(b) Describe the development of an endosperm in a viable seed. Why does endosperm development
precede embryo development?
(c) Give an example of an angiosperm seed that has a perisperm. Name the part the perisperm develops
from.
49: Read the statement and answer the questions that follow:
A flower of brinjal has 520 ovules in its ovary.
However, it produces a fruits with only 480 viable seeds.
(a) What could have prevented the rest of the 40 ovules from mating into viable seeds? Explain giving a
reasons.
(b) Describe the development of a dicot embryo in a viable seed.
(c) Why certain angiosperm seeds are albuminous while others are exalbuminous? Explain.
50: (a) Explain the post-pollination events leading to seed production in angiosperms.
(b) List the different types of pollination depending upon the source of pollen grain.
51: (a) Describe the process of megasporogenesis, in an angiosperm.
(b) Draw a diagram of a mature embryo sac of angiosperm, label its any six parts.
52: (a) Where does microsporogenesis occur in an angiosperm? Describe the process of microsporogenesis.
(b) Draw a labelled diagram of the two-celled male gametophyte of an angiosperm. How is the
threecelled male gametophyte different from it?
53: Where does the process of megasporogenesis start in an angiosperm? Describe the process upto
the formation of embryo sac.
54: (a) Describe any two devices in a flowering plant which prevent both autogamy and geitonogamy.
(b) Explain the events upto double fertilisation after the pollen tube enters one of the synergids in an
ovule of an angiosperm.
55: Banana is a true fruit as well as a parthenocarpic fruit. Give reason.
56: Pollen grains retain viability for months in plants belonging to different families given below.
(i) Solanaceae. (ii) Granineae.
(iii) Leuminosae. (iv)
(v) Liliaceae
(i) ,(ii) and (v) (i), (iii) and (iv)
(ii),(iv) and (v) (i),(iii) and (v)
57: Enclosed within the integument of a typical anatropus ovule is a diploid mass of cellular
tissue known as :
Nucellus Embryo sac
Megaspore mother cell. Synergids.
58: The aquatic plant having long and ribbon like pollen grains is
Vallisneria. Hydrilla
Eichhornia. Zostera.
59: Which condition of gynoecium (pistil) is shown
(i) multicarpellary apocarpous, (i)multicarpellary syncarpous,
(ii) multicarpellary syncarpous. (ii) multicarpellary apocarpous
(i) bicarpellary apocarpous, (i) bicarpellary syncarpous,
(ii) bicarpellary syncarpous (ii) bicarpellary apocarpous
60: To overcome incompatible pollination so as to get desired hybrids, a plant breeder must
have known
Pollen-nucellar interaction. Pollen-egg cell interaction.
Pollen-pistil interaction. Pollen-embryo sac interaction.
61: Floral reward's provided by insect pollinated flowers to sustain animal visit are:
Nectar and fragrance. Nectar and Pollen grains.
Pollen grains and fragrance. Fragrance and bright colour.
62: Which of the following outbreeding devices are used by majority of flowering plants to
prevent the inbreeding depression.
(i) Pollen release and stigma receptivity are not synchronised.
(ii) Different positions of anther and stigma.
(iii) Production of different types of pollen grains.
(iv) Formation of unisexual flower with bisexual flower.
(v) Preventing self pollen from fertilizing the ovules by inhibiting pollen germination.
(i), (ii) and (v) (ii), (iii) and (v)
(iii), (iv) and (v) (i), (iii) and (v)
63: Choose the correct labelling for the part X,Y and Z in the given figure of the stages in
embryo development of dicot:
X is suspensor, Y is radicle and Z is X is radicle, Y is cotyledon and Z is
cotyledon. suspensor.
X is cotyledon, Y is suspensor and Z is
X is zygote, Y is radicle and Z is cotyledon.
radicle.
64: In a typical dicotyledonous embryo, the portion of embryonal axis above the level of
cotyledon is
Plumule Coleoptile.
Epicotyle. Hypocotyl.
65: Researchers over the world are trying to transfer apomictic genes to hybrid varieties as
hybrid characters in the progeny:
do not segregate. segregate.
develop genetic variations. will remain unexpressed
66: Assertion (A): Apomictic embryos are generally identical to the parent plant.
Reason (R): Apomixis is the production of seeds without fetilisation.
Both assertion (A) and reason (R) are true Both assertion (A) and reason (R) are true but
and reason (R) is the correct explanation of reason (R) is not the correct explanation of
assertion (A). assertion (A).
Assertion (A) is true but reason (R) is false. Assertion (A) is false but reason (R) is true.
67: "Cells of the tapetum of a microsporangium are usually multinucleate" Give reason.
68: State ONE characteristic of a pollen grain that can help students identify:
(a) a water-pollinated pollen grain.
(b) an animal-pollinated pollen grain.
69: Some flowers, selected for artificial hybridization, do not require emasculation but bagging
is essential for them. Give a reason.
70: List the different types of pollination depending upon the source of pollen grain.
71: Some flowers, selected for artificial hybridisation, do not require emasculation but bagging
is essential for them. Give a reason.
72: Mention the function of coleorhiza.
73: A non-biology person is quite shocked to know that apple is a false fruit, mango is a true
fruit and banana is a seedless fruit. As a biology student how would you satisfy this person?
74: Remnants of nucellus are persistent during seed development in:
pea groundnut
wheat black pepper
75: The wall layer of microsporangium which nourishes the pollen grain is:
epidermis endothecium
middle layers tapetum
76: In some species of flowering plants, fruits develop without the process of fertilisation.
Which of these can be an identifying factor of such fruits?
They are not developed from the ovary. They are always composite.
They are always seedless. They are not juicy.
77: Kiwi is a dioecious species. Which of the following methods can be definitely RULED OUT
as a possible mode of pollination in its case?
(P) cleistogamous autogamy
(Q) chasmogamous autogamy
(R) geitonogamy
(S) xenogamy
only P and R only P and Q
only Q and S only P, Q and R
78: Study the given diagram and choose the correct option against ‘A’ and ‘B’
Refer figure from the list of digrams number 4
A-Egg apparatus; B-Polar body A-Antipodals; B-Egg apparatus
A-Synergids; B- Egg apparatus A-Central cell; B-Antipodals
79: Choose the option that gives the correct number of pollen grains that will be formed after
325 microspore mother cells undergo microsporogenesis.
325 650
1300 975
80: Directions: In the following questions, a statement of assertion (A) is followed by a
statement of reason (R). Mark the correct choice as:
Assertion (A):Primary endosperm nucleus is diploid.
Reason (R): It is the product of double fertilisation.
Both assertion (A) and reason (R) are true Both assertion (A) and reason (R) are true but
and reason (R) is the correct explanation of reason (R) is not the correct explanation of
assertion (A). assertion (A).
Assertion (A) is true but reason (R) is false. Assertion (A) is false but reason (R) is true.
81: Directions: In the following questions, a statement of assertion (A) is followed by a
statement of reason (R). Mark the correct choice as:
Assertion (A): Apomictic fruits are seedless.
Reason (R): Apomictic fruits are formed without fertilisation.
Both assertion (A) and reason (R) are true Both assertion (A) and reason (R) are true but
and reason (R) is the correct explanation of reason (R) is not the correct explanation of
assertion (A). assertion (A).
Assertion (A) is true but reason (R) is false. Assertion (A) is false but reason (R) is true.
82: Directions: In the following questions, a statement of assertion (A) is followed by a
statement of reason (R). Mark the correct choice as:
Assertion (A): Endosperm in a flowering plant is formed before the formation of the embryo.
Reason (R): The endosperm provides food to the developing embryo.
Both assertion (A) and reason (R) are true Both assertion (A) and reason (R) are true but
and reason (R) is the correct explanation of reason (R) is not the correct explanation of
assertion (A). assertion (A).
Assertion (A) is true but reason (R) is false. Assertion (A) is false but reason (R) is true.
83: Directions: In the following questions, a statement of assertion (A) is followed by a
statement of reason (R). Mark the correct choice as:
Assertion (A): Pollen tube germinates through the germ pores on the pollen grains
Reason (R): Pollen-pistil compatibility chemicals help to dissolve sporopollenin for the
pollen tube to germinate.
Both assertion (A) and reason (R) are true Both assertion (A) and reason (R) are true but
and reason (R) is the correct explanation of reason (R) is not the correct explanation of
assertion (A). assertion (A).
Assertion (A) is true but reason (R) is false. Assertion (A) is false but reason (R) is true.
84: Directions: In the following questions, a statement of assertion (A) is followed by a
statement of reason (R). Mark the correct choice as:
Assertion (A): Perisperm is a haploid tissue.
Reason (R): Perisperm is the remains of nucellus which surround the embryo in certain
seeds.
Both assertion (A) and reason (R) are true Both assertion (A) and reason (R) are true but
and reason (R) is the correct explanation of reason (R) is not the correct explanation of
assertion (A). assertion (A).
Assertion (A) is true but reason (R) is false. Assertion (A) is false but reason (R) is true.
85: Directions: In the following questions, a statement of assertion (A) is followed by a
statement of reason (R). Mark the correct choice as:
Assertion (A): The coconut endosperm is multinucleate throughout its development.
Reason (R): Some endosperms undergo free nuclear division without the formation of
distinct cell.
Both assertion (A) and reason (R) are true Both assertion (A) and reason (R) are true but
and reason (R) is the correct explanation of reason (R) is not the correct explanation of
assertion (A). assertion (A).
Assertion (A) is true but reason (R) is false. Assertion (A) is false but reason (R) is true.
86: Directions: In the following questions, a statement of assertion (A) is followed by a
statement of reason (R). Mark the correct choice as:
Assertion (A): Apomixis and parthenocarpy are both asexual modes of reproduction.
Reason (R): Seeds are not produced in both apomixis and parthenocarpy.
Both assertion (A) and reason (R) are true Both assertion (A) and reason (R) are true but
and reason (R) is the correct explanation of reason (R) is not the correct explanation of
assertion (A). assertion (A).
Assertion (A) is true but reason (R) is false. Assertion (A) is false but reason (R) is true.
87: The image below shows a blue-throated humming bird visiting a flower.
What is the benefit that the flower derives from the humming bird? Justify.
88: The image below shows a blue-throated humming bird visiting a flower.
What kind of pollen grains would a flower most likely have when it is seen to be visited
regularly by birds and butterflies?
89: The image below shows a blue-throated humming bird visiting a flower.
"Self-pollinated flowers mostly do not need pollinating agents." Mention whether this
statement is true or false with a reason for your answer.
90: A floral formula is a concise representation of the structure of a flower. the following
symbols are used to represent different facts about the flower:
K= calyx
C= corolla
A= androecium
G= gynoecium
For example, a floral formula K5C5A5G2 means that the flower has 5 sepals, 5 petals, 5
stamens and 2 carpels in the ovary.
Rishabh comes across a floral formula K6C6A10G0 for all flowers in a plant.
What does the floral formula indicate about the sexuality of the flowers?
91: A floral formula is a concise representation of the structure of a flower. the following
symbols are used to represent different facts about the flower:
K= calyx
C= corolla
A= androecium
G= gynoecium
For example, a floral formula K5C5A5G2 means that the flower has 5 sepals, 5 petals, 5
stamens and 2 carpels in the ovary.
Rishabh comes across a floral formula K6C6A10G0 for all flowers in a plant.
What kind of pollination (self or cross) will the plant show? Justify.
92: A floral formula is a concise representation of the structure of a flower. the following
symbols are used to represent different facts about the flower:
K= calyx
C= corolla
A= androecium
G= gynoecium
For example, a floral formula K5C5A5G2 means that the flower has 5 sepals, 5 petals, 5
stamens and 2 carpels in the ovary.
Rishabh comes across a floral formula K6C6A10G0 for all flowers in a plant.
What kind of fruits will this plant bear and why?
93: A floral formula is a concise representation of the structure of a flower. the following
symbols are used to represent different facts about the flower:
K= calyx
C= corolla
A= androecium
G= gynoecium
For example, a floral formula K5C5A5G2 means that the flower has 5 sepals, 5 petals, 5
stamens and 2 carpels in the ovary.
Rishabh comes across a floral formula K6C6A10G0 for all flowers in a plant.
If this flower is seen to have large, yellow showy petals, what is the most likely pollinating
agent for the flower?
94: Write the function of ‘germ pore’ in a pollen grain of an angiosperm.
