CBSE Class 12 Biology Sexual Reproduction in Flowering Plants MCQs Set E

Question. Strobilanthes kunthiana is also called
(a) Neelakurinji
(b) Peela kuranji
(c) Hara kuranji
(d) Kala kuranji
Answer : a 

Question. Arrange the organisms shown below in the increasing order of their lifespans.
(a) Parrot < Crow < Crocodile
(b) Crow < Crocodile < Parrot
(c) Crocodile < Parrot < Crow
(d) Parrot < Crocodile < Crow
Answer : b

Question. Reproduction in Amoeba is carried out through
(a) gemmule formation
(b) binary fission
(c) budding
(d) plasmotomy
Answer : b

Question. The site of origin of the new plantlets in potato, Dahlia, ginger and banana is
(a) floral buds present on stem
(b) internodes of modified stem
(c) nodes of modified stem
(d) adventitious buds present on root
Answer : c 

Question. Fusion of male and female gametes is called
(a) syngamy
(b) fertilisation
(c) Both (a) and (b)
(d) heterogamy
Answer : c

Question. Lifespan of tortoise is
(a) 100-150 years
(b) 250 years
(c) 20 years
(d) 1 year
Answer : a

Question. Single-celled animals are said to be immortal because
(a) they grow indefinitely in size
(b) they can tolerate any degree of change in temperature
(c) they can reproduce throughout their lifespan
(d) they continue to live as their daughter cells
Answer : d 

Question. Which one of the following is correctly matched?
(a) Onion – Bulb CBSE-AIPMT 2012
(b) Ginger – Sucker
(c) Chlamydomonas – Conidia
(d) Yeast – Zoospores
Answer : a

Question. Asexual reproduction is a method of reproduction in which participation of ……… takes place.
(a) one individual
(b) two individuals (same species)
(c) multi-individuals
(d) two individuals (different species)
Answer : a  

Question. Gemmule formation is a common mode of reproduction in
(a) Hydra
(b) sponge
(c) Penicillium
(d) Amoeba
Answer : b

Question. Which one of the following options shows two plants in which new plantlets arise from the same organ?
(a) Guava and ginger
(b) Potato and sweet potato
(c) Dahlia and mint
(d) Potato and sugarcane
Answer : a

Question. Zoospores are
(a) motile gametes of Chlamydomonas
(b) non-motile gametes of sponges
(c) motile gametes of Hydra
(d) non-motile gametes of Penicillium
Answer : a

Question. Hydra reproduces by
(a) Budding
(b) Fragmentation
(c) Gemmule formation
(d) Both (a) and (b)
Answer : d

Question. Some organisms are capable of asexual or sexual reproduction. Under favourable conditions, reproduction proceeds asexually. When conditions become more stressful reproduction switches to a sexual mode. Why?
(a) Sexual reproduction is simple and more rapid allowing larger numbers of offspring to be produced
(b) Sexual reproduction requires two separate individuals, who can mutually provide nutrient support during stress
(c) Sexual reproduction produces individuals with new combinations of recombined chromosomes increasing diversity
(d) Asexual reproduction requires more energy
Answer : c 

Question. The growth phase of an organism before attaining sexual maturity is referred to as
(a) juvenile phase
(b) pre-reproductive phase
(c) Both (a) and
(b) (d) None of these
Answer : c 

Question. Offsprings of oviparous animals have less chances of survival as compared to those of viviparous animals because
(a) proper embryonic care and protection is absent
(b) embryo does not develop completely
(c) progenies are of smaller size
(d) genetic variations do not occur
Answer : a

Question. Which of the following options is/are correct about pollination?
(a) Occurs in almost all flowering plants
(b) Facilitates pollen transfer to stigma
(c) Both (a) and (b)
(d) None of the above
Answer : c

Question. Essential and most critical event in sexual reproduction is
(a) fertilisation
(b) division in male and female gametes
(c) Both (a) and (b)
(d) None of the above
Answer : c 

Question. Offsets are produced by NEET 2018
(a) parthenocarpy
(b) mitotic divisions
(c) meiotic divisions
(d) parthenogenesis
Answer : c 

Question. Chances of survival of young ones are more in the case of…………. individuals.
(a) oviparous
(b) viviparous
(c) ovoviviparous
(d) None of these
Answer : b

Question. Which of the following is not a vegetative propagule?
(a) Offset
(b) Antherozoid
(c) Rhizome
(d) Bulbil
Answer : b

Question. Reproduction can be considered as
(a) a biological process
(b) a cycle of birth, growth and death
(c) a process that enables continuity of species
(d) All of the above
Answer : d

Question. If a leaf cell of Agave have X chromosome, then what will be the number of chromosomes in a cell of its bulbil?
(a) 2X
(b) X
(c) X/4
(d) X/2
Answer : b

Question. Identify the plant which contains the features given below.
I. The plant was introduced in India because of its beautiful flowers and shape of leaves.
II. It can propagate vegetatively at a phenomenal rate and spread all over water body in a short period.
III. It is very difficult to get rid of these plants.   
Answer : b

Question. Cell division is the mode of reproduction in
(a) monerans
(b) protists
(c) Both (a) and (b)
(d) None of the above
Answer : c 

Question. Which one of the following flowers only once in its lifetime? NEET 2018
(a) Mango
(b) Jackfruit
(c) Bamboo species
(d) Papaya
Answer : c

Question. Refer to the given figures and identify X and Y in these.   
(a) X–Buds, Y–Nodes
(b) X–Nodes, Y–Adventitious buds
(c) X–Nodes, Y–Adventitious roots
(d) X–Eyes, Y–Nodes
Answer : b 

Question. Oestrus cycle is cyclic change in the activities of ovaries and accessory duct in non-primates during
(a) reproductive (seasonal) period
(b) maturation period
(c) ageing period
(d) juvenile period
Answer : a

Question.In Amoeba, under unfavourable conditions, …A…
takes place but under favourable conditions …B…occurs.
Identify A and B.
A B
(a) Sporulation Encystation
(b) Encystation Sporulation
(c) Binary fission Encystation
(d) Multiple fission Encystation
Answer : b 

Question. Study the following diagram and the information given below. 
A. Zoospore of Chlamydomonas.
B. Conidia of Penicillium.
C. Buds in Hydra.
D. Gemmulesin sponge.
All the above are
(a) bodies involved in sexual reproduction
(b) bodies involved in asexual reproduction
(c) bodies of young ones
(d) All the above are correct
Answer : b

Question. Select the correct sequence from the following.
I. Juvenile phase®Senescent phase®Reproductive phase
II. Juvenile phase®Reproductive phase®Senescent phase
III. Reproductive phase®Juvenile phase®Senescent phase
IV. Pre-reproductive phase®Reproductive phase® Senescent phase
(a) I and II
(b) I and IV
(c) III and IV
(d) II and IV
Answer : d 

Question. Study the given figures and processes representing the binary fission in Amoeba. 
A. Daughter cells formation
B. Enlargement of nucleus
C. Parent cell
D. Constricted cell formation
E. Minimisation of pseudopodia
Arrange the figures and processes in the correct sequence and select the correct answer.
(a) D® C® A® B® E
(b) C® D® A® B® E
(c) C® E® B® D® A
(d) D® C® B® E® A
Answer : c

Question. Refer the given figures which show three different types of fission.
A. Longitudinal fission
B. Transverse fission
C. Multiple fission
Select the option which correctly matches them with the organism in which they occur.
           A                  B                  C
(a) Euglena         Plasmodium     Amoeba
(b) Plasmodium   Paramecium     Euglena
(c) Euglena         Paramecium     Escherichia
(d) Euglena         Paramecium     Amoeba
Answer : d

Very Short Answer Type Questions

Question. How many microsporangia are present in a typical anther of angiosperm.
Answer : Usually Four.

Question. An anther with a malfunctioning tapetum often fails to produce viable male gametophytes. Give any one reason. 
Answer : Because the tapetum provides nourishment for the development of pollen grains.

Short Answer Type Questions

Question. Mention the ploidy of the different types of cells present in the female gametophyte of an angiosperm. 
Answer : Synergids = n/haploid, egg = n/haploid, polar nuclei = n/haploid, antipodals = n/haploid = ½ × 4 // all types of cell of female gemetophyte are haploid / n = 2 

Question. Name the organic materials exine and intine of an angiosperm pollen grain are made up of.
Explain the role of exine.
Answer : The exine is made up of sporopollenin, which is one of the most resistant organic material. The intine layer is made up of cellulose and pectin materials. The exine is hard and hence protects the pollen grains during adverse conditions. 
Detailed Answer :
Exine is made up of a substance called “sporopollenin” while intine is made up of pectocellulose.
Sporopollenin is a resistant fatty substance therefore, exine functions as a protective covering of pollen grain. It also possesses the proteins for enzymatic and compatibility reactions.

Question. ”Pollen grains in wheat are shed at 3-celled stage while in peas they are shed at 2-celled stage.” Explain. Where are germ pores present in a pollen grain ?
Answer : At the time of shedding wheat pollen consist of one vegetative and two male gametes (3 celled), While pea pollen consists of one vegetative and one generative cell (2 celled) Germ pores are present on the exine (Where sporopollenin is absent) 

Question. Where is sporopollenin present in plants ? State its significance with reference to its chemical nature.
Answer : Present in exine of pollen / pollen grain Sporopollenin is the most resistant organic materials. It can withstand high temperature and strong acids and alkali. It cannot be degraded by enzymes. 

Question. Explain giving reasons why pollen grains can be best preserved as fossils.
Answer : Pollen grains are best preserved as fossils because of the following reasons :
(i) The sporopollenin of exine is highly resistant to the action of strong acids and alkali and can withstand a high temperature.
(ii) It is not easily degraded by any of the enzyme known so far. 

Question. (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.
Answer : (i) No
Examples :
(a) Cereals / rice / wheat – pollen grains / loose viability within thirty minutes of their release.
(b) In some members of Rosaceae / leguminosae maintain viability for months.
(ii) Using cryopreservation techniques / in liquid nitrogen (– 196º C)
Maintaining viability / preserving threatened species / preserving commercially important plants / to be used for crop breeding programmes.

Long Answer Type Questions

Question. Explain the process of microsporogenesis in angiosperms. 
Answer : Process of microsporogenesis:
(i) When the anther develops, each cell of sporogenous tissue functions as microspore mother cell (MMC) or pollen mother cell (PMC) and undergoes meiotic divisions to form microspore tetrads.
(ii) The process of formation of microspores from a pollen mother cell (PMC) through meiosis is called microsporogenesis.
(iii) The microspores get arranged in a cluster of four cells and hence are microspore tetrad.
(iv) As the anthers mature and dehydrate, the microspores dissociate from each other and develop into pollen grains.
(v) In each microsporangium, thousands of pollen grains are formed and released with the dehiscence of anther.

Question. (i) Describe the development of a 7-celled female gametophyte from a megaspore mother cell in an angiosperm.
(ii) What is the role of endothecium and tapetum in an anther ?
Answer : (i) Development of female gametophyte :
The female reproductive part of a flower is gynoecium, which consists of three parts— stigma, style and ovary. The ovules are formed in the ovary and attach to it through placenta. The ovule is surrounded by one to two protective layers called integuments, leaving a small opening at one end termed as a micropyle. The stalk of the ovule is called funiculus. The ovule is composed of multi celled cellular tissue called the nucellus. A hypodermal cell of nucellus at the micropylar end enlarges and becomes a megaspore mother cell that undergoes meiosis to form a linear tetrad of four megaspores.
Out of four, only one remains functional and three megaspores degenerate. The functional megaspore undergoes three successive mitotic divisions to form eight nuclei, which arrange themselves into three groups. Three nuclei migrate towards the micro-pylar end and form the egg apparatus. Other three nuclei form antipodal cells at chalazal end. The remaining two nuclei come together as polar nuclei which fuse to form secondary nucleus in the centre of the embryo sac.
(ii) Role of endothecium : Endothecium performs the function of protection and helps in dehiscence of anther to release the pollen.
Role of tapetum : It nourishes the developing pollen grains.