3

Q1. The common mode of sexual reproduction in Chlamydomonas is 

• 1) Anisogamous
• 2) Isogamous
• 3) Hologamous
• 4) Oogamous

Solution

Different species of Chlamydomonas produce different types of gametes. Sexual reproduction in Chlamydomonas may be hologamy, isogamy, anisogamy and oogamy, but isogamy is the most simplest and common type and oogamy is the most advanced type of sexual reproduction. 

Q2. The male gamete in angiosperms is produced by  

• 1) Generative cell  
• 2) Microspore cell  
• 3) Tube cell  
• 4) Vegetative cell  

Solution

The generative cell is a cell of the male gametophyte. Generative cells divide to give rise to male gametes in angiosperms.  

Q3. Protonema has which of the following characteristics?  

• 1) Haploid and found in mosses  
• 2) Haploid and found in pteridophytes  
• 3) Diploid and found in liverworts  
• 4) Diploid and found in pteridophytes  

Solution

Protonema is one of the stages of the gametophyte in the life cycle of moss. It develops from a spore. It is green, branched, filamentous and creeping.  

Q4. The phylogenetic system of classification is based on

• 1) Evolutionary relationships
• 2) Chemical constituents
• 3) Morphological features
• 4) Floral characters

Solution

The phylogenetic classification system is based on evolutionary relationships, and it is an acceptable method of classification at present.

Q5. Protonema occurs in the life cycle of 

• 1) Spirogyra
• 2) Riccia
• 3) Funaria
• 4) Chlamydomonas

Solution

Protonema is the juvenile stage of Funaria. It is a branched, green filamentous structure formed by the germination of spores under favourable conditions. 

Q6. Which one of the following is not a characteristic feature of bryophytes?  

• 1) Dominant gametophytic generation  
• 2) Vascular tissue  
• 3) Amphibious habitat  
• 4) Filamentous rhizoids  

Solution

Bryophytes do not have vascular tissues. Instead, they have simple conducting strand to transport water, minerals and other food materials.  

Q7. Why are bryophytes called amphibians of the plant kingdom?

Solution

Bryophytes can live in soil, but they are dependent on water for sexual reproduction; therefore, they are called amphibians of the plant kingdom.

Q8. Write important characteristics of gymnosperms.

Solution

Characteristics of Gymnosperms: Ovules are not covered by ovary. Seeds are naked. Gymnosperms exhibit a tap root system. Gymnosperms are heterosporous. (Write any 3)

Q9. Gymnosperms are characterised by

• 1) Seeds inside fruits
• 2) Multiflagellate sperms
• 3) Winged seeds
• 4) Naked seeds

Solution

In gymnosperms, seeds are naked and are not embedded in fruits.

Q10. Sporophyte dependent on gametophyte occurs in which of the following options?

• 1) Bryophytes
• 2) Algae
• 3) Pteridophytes
• 4) Fungi

Solution

In Bryophytes, sporophyte is attached to the gametophyte. Gametophyte is photosynthetic, and hence, sporophyte gets its nourishment from the gametophyte.

Q11. The product of conjugation in Spirogyra or fertilisation of Chlamydomonas is 

• 1) Oospore
• 2) Zygospore
• 3) Carpospore
• 4) Zoospore

Solution

In Chlamydomonas, the zygospore is the resultant of isogamy, anisogamy or oogamy.     In Spirogyra, sexual reproduction occurs through conjugation which may be scalariform or lateral. The resulting zygote secretes a thick wall and is called zygospore. 

Q12. Meiosis occurs in Funaria in which of the following cells?

• 1) Zygotic cells
• 2) Spore mother cells
• 3) Archegonial cells
• 4) Antheridial cells

Solution

In funaria, antherozoids swim towards the archegonium. One of the antherozoids fuses with the archegonium to form the zygote. With the formation of zygote, the sporophytic phase begins, during which the zygote undergoes meiosis to form sporogonium.

Q13. Find the odd one out with respect to haplontic life cycle.

• 1) Ulothrix
• 2) Chlamydomonas
• 3) Spirogyra
• 4) Ectocarpus

Solution

In the haplontic life cycle, the plant body is gametophyte and independent. The sporophyte is not free-living and is dependent on the gametophyte. It is observed in majority of green algae such as Ulothrix, Spirogyra and Chlamydomonas.

Q14. State any two important features of dicotyledons.

Solution

Important features of dicotyledons: Seeds of dicotyledons show two cotyledons. Leaves of dicotyledons show reticulate venation. Vascular bundles are arranged in concentric circles.

Q15. The plant body is the thallus in

• 1) Algae
• 2) Pteridophyta
• 3) Gymnospermae
• 4) Bryophyta

Solution

The thallus is an undifferentiated mass of cells. In algae, the plant body consists of numerous undifferentiated cells (tissue-level organisation is absent).

Q16. In Pinus, if the pollen grain has 6 chromosomes, then its endosperm will have  

• 1) 18 chromosomes
• 2) 24 chromosomes
• 3) 6 chromosomes
• 4) 12 chromosomes

Solution

In gymnosperms such as Pinus, both pollen grains and endosperm are haploid and are formed before fertilisation. If the pollen grain has haploid number of chromosomes equal to 6, then its endosperm will also have 6 chromosomes. 

Q17. The nutrient medium is made semi-solid by adding

• 1) Agar-agar
• 2) Pectin
• 3) Sodium chloride
• 4) Water

Solution

Agar is the substance obtained from red algae. It is obtained from Gelidium and Gracilaria.

Q18. Bryophytes are distinguishable from fungi in having which of the following characteristics?  

• 1) Sterile jacket layer around sex organs  
• 2) Gametophytic plant body  
• 3) Flagellate gametes  
• 4) Land habit  

Solution

In fungi, spores are thin walled and flagellate but in bryophytes the antherozoids and archegonia are well jacketed.  

Q19. Consider the following statements with respect to characteristic features of the kingdom.     (A) In Animalia, the mode of nutrition is autotrophic.     (B) In Monera, the nuclear membrane is present.     (C) In Protista, the cell type is prokaryotic.       (D) In Plantae, the cell wall is present.     Of the above statements,  

• 1) A, B and C are correct.  
• 2) C alone is correct.  
• 3) D alone is correct.  
• 4) A alone is correct.  
• 5) B alone is correct.  

Solution

(A) In Animalia, the mode of nutrition is heterotrophic.     (B) In Monera, the nuclear membrane is absent.     (C) Protists are unicellular eukaryotes.       (D) In Plantae, the cell wall is present.  

Q20. Brown algae have a characteristic pigment of  

• 1) Haematochrome  
• 2) Phycoerythrin  
• 3) Fucoxanthin  
• 4) Phycocyanin  

Solution

Fucoxanthin is a carotenoid pigment which imparts a brown colour to algae. It is sensitive to shorter wavelengths of light. Hence, species of brown algae are found in shallow water.  

Q21. What does a pollen chamber in a gymnosperm represents?

Solution

In gymnosperms, the pollen chamber represents a cavity in the ovule in which pollen grains are stored after pollination.

Q22. Agar is commercially received from

• 1) Brown algae
• 2) Blue-green algae
• 3) Green algae
• 4) Red algae

Solution

Red algae Gelidium and Gracilaria are used for the commercial production of agar. Agar is used in jellies. It is also used in microbiology techniques to grow microbes.

Q23. Bryophytes depend on water because water is required for which of the following processes?

• 1) Fertilisation of homosporous plants
• 2) Vegetative propagation
• 3) Swimming of sperm up to egg inside archegonium
• 4) Filling archegonium for fertilisation

Solution

Bryophytes require a layer of water on the soil so that the antherozoids can swim to the archegonium. Once they reach the archegonium, one of the antherozoids fuses with the egg cell to form the zygote.

Q24. A common feature between bryophytes and pteridophytes is which of the options listed below?  

• 1) Gametophyte dependent on sporophyte  
• 2) Sporophyte dependent on gametophyte  
• 3) Multicellular sex organs with sterile jacket  
• 4) Absence of sporophyte  

Solution

Multicellular sex organs with sterile jacket are a common feature of bryophytes and pteridophytes.  

Q25. In ferns, meiosis occurs when 

• 1) Spores germinate
• 2) Spores are formed
• 3) Gametes are formed
• 4) Antheridia and archegonia are formed

Solution

In ferns, sexual reproduction takes place through spores which are borne in sporangia. 

Q26. The ‘wing’ of Pinus seed is derived from the 

• 1) Surface of ovuliferous scales
• 2) All of the above
• 3) Testa
• 4) Testa and tegmen

Solution

The wings of seeds in Pinus are thin, membranous, diploid and develop jointly from the basal upper surface of ovuliferous scales and the outer layer of the integument of the ovule. 

Q27. What is anisogamous fusion?

Solution

Anisogamous fusion is the fusion between two gametes which are dissimilar in size.

Q28. In the life cycle of Funaria, spores are the beginning of which of the following terms?  

• 1) Both 1 and 2 above  
• 2) Peristome  
• 3) Gametophytic generation  
• 4) Sporophytic generation  

Solution

In the life cycle of Funaria, spores are the beginning of the gametophytic generation. Spores germinate to give rise to the gametophyte.  

Q29. Sago of Cycas is given to patients with stomach disorders because it is  

• 1) Tastier  
• 2) Cheap  
• 3) Easily digestible with less starch  
• 4) With high nutritive value  

Solution

Sago is a pure starch extract in the liquid state. In the solid state, it is in the form of granules. The sago obtained from Cycas circinalis is easily digestible. It is a major staple food for people from New Guinea.  

Q30. Phycology deals with the study of

• 1) Algae
• 2) Fungi
• 3) Bryophytes
• 4) Microbes

Solution

Phycology is the branch of biology which deals with the study of algae. It is also known as algology.

Q31. The moss plant has which of the following characteristics?

• 1) Predominantly gametophyte with sporophyte attached to it
• 2) Gametophyte
• 3) Sometime gametophyte and sometime sporophyte
• 4) Sporophyte

Solution

Gametophyte is the dominant stage in the moss plant.

Q32. The gametophytic generation is dominant in which of the following terms?

• 1) Angiosperms
• 2) Bryophytes
• 3) Gymnosperms
• 4) Pteridophytes

Solution

In Bryophytes, the sporophyte is attached to the photosynthetic gametophyte.

Q33. Explain the modes of reproduction in Ulothrix.

Solution

In Ulothrix, reproduction may occur by the following methods: 1. Vegetative reproduction by fragmentation or by formation of different types of spores. 2. Asexual reproduction by flagellated zoospores. 3. Sexual reproduction by the isogamous, anisogamous or oogamous fusion of gametes.

Q34. In which of the following would you place the plants with vascular tissue lacking seeds?

• 1) Algae
• 2) Bryophytes
• 3) Gymnosperms
• 4) Pteridophytes

Solution

Pteridophytes are terrestrial, vascular and seedless plants.

Q35. Floridean starch occurs in  

• 1) Phaeophyceae  
• 2) Myxophyceae  
• 3) Chlorophyceae  
• 4) Rhodophyceae  

Solution

In Rhodophyceae (red algae), food is stored in the form of floridean starch. Its grains are stored outside the chloroplast.  

Q36. Resin and turpentine are products of

• 1) Eucalyptus
• 2) Pine
• 3) Teak
• 4) Oak

Solution

Turpentine is obtained from pine resin.

Q37. Name the plant body which produces gametes by mitosis.

Solution

Gametophyte

Q38. A multicellular jacketed female sex organ of bryophytes is called which of the following terms?  

• 1) Carpogonium  
• 2) Ascogonium  
• 3) Trichogyne  
• 4) Archegonium  

Solution

Archegonium is flask-shaped and jacketed. Its lower part is swollen and the anterior part is apical in shape. It produces egg cells.  

Q39. Mosses and ferns are found in moist and shady places because both have which of the following requirements?  

• 1) Depend for their nutrition on microorganisms which can survive only at low temperature  
• 2) Require the presence of water for fertilisation  
• 3) Cannot compete with sun-loving plants  
• 4) Do not need sunlight for photosynthesis  

Solution

Mosses lack vascular tissues. Also both mosses and ferns require water to carry out sexual reproduction.  

Q40. A plant in which sporophytic generation is represented by zygote is  

• 1) Pinus
• 2) Dryopteris
• 3) Chlamydomonas
• 4) Selaginella

Solution

Chlamydomonas reproduces asexually through the formation of zoospores and sexually through gametes. Gametes fuse to produce a diploid zygote representing the sporophytic generation. 

Q41. Pinus differs from mango in having 

• 1) Wood
• 2) Ovules not enclosed in an ovary
• 3) Green leaves
• 4) Tree habit

Solution

Gymnosperms are known as seeded plants without flowers because their ovules are not covered and lie naked on the surfaces of specialised leaves arranged into cones. 

Q42. In gymnosperms, the haploid structures are 

• 1) Pollen grain, leaf and root
• 2) Megaspore, integument and root
• 3) Megaspore, pollen grain and endosperm
• 4) Megaspore, endosperm and embryo

Solution

In gymnosperms, the megaspore is the first cell of the female gametophyte and undergoes repeated divisions to form a multicellular female gametophyte which serves as an endosperm. Microspores or pollen grains are the first cell of the male gametophyte and are haploid in nature. 

Q43. Fusion of two gametes which are dissimilar in size is termed  

• 1) Oogamy  
• 2) Isogamy  
• 3) Zoogamy  
• 4) Anisogamy  

Solution

Anisogamy is the fusion between two gametes which are either dissimilar in size or in both size and morphology. It is observed in Chlamydomonas. Oogamy is a type of anisogamy.  

Q44. In Chlorophyceae, sexual reproduction occurs by  

• 1) Anisogamy and oogamy  
• 2) Oogamy only  
• 3) Isogamy and anisogamy  
• 4) Isogamy, anisogamy and oogamy  

Solution

In Chlorophyceae, sexual reproduction occurs by isogamy, anisogamy or oogamy.     Isogamy: The gametes are similar in size and shape. These gametes are not classified as male or female. They are noted as ‘+’ and ‘−’ strains.     Anisogamy: It is the fusion between two gametes which are either dissimilar in size or in both size and morphology. It is observed in Chlamydomonas.     Oogamy: Oogamy is a type of anisogamy. The male gamete is smaller in size than the female gamete.  

Q45. In plants, haploid as well as diploid cells undergo mitosis. Hence, during the life cycle of a sexually reproducing plant, there is an alternation of generation between gametophyte and sporophyte. Name the dominant phase seen in the life cycle of gymnosperms. Name three types of life cycles shown by the plants. What is the difference between the life cycles of bryophytes and pteridophytes? What value do you learn from the life cycles of plants?

Solution

Sporophyte is the dominant phase seen in the life cycle of gymnosperms. The three types of life cycles shown by the plants are haplontic, diplontic and haplodiplontic. In bryophytes, the gametophyte represents the dominant phase. In pteridophytes, the sporophyte represents the dominant phase All individuals have different ways of implementing their values and culture. Irrespective of these, all should be respected and allowed to live with dignity.

Q46. Which is the photosynthetic phase in the life cycle of ferns?  

Solution

Diploid sporophyte  

Q47. Write the name of the species of moss which provides peat?

Solution

Sphagnum 

Q48. Male cone of Pinus is made of  

• 1) Ligules  
• 2) Anthers  
• 3) Microsporophylls  
• 4) Megasporophylls  

Solution

Microsporophylls contain sporangia in which haploid microspores develop. Microsporophylls in pine are present on male strobili.  

Q49. Write the pigments found in members of the Phaeophyceae group of algae.

Solution

Chlorophyll a, chlorophyll c, carotenoids and xanthophyll (fucoxanthin).

Q50. What are pyrenoids?  

Solution

Pyrenoids are food storage bodies found in members of Chlorophyceae.  

Q51. In Chlorophyceae, sexual reproduction occurs by  

• 1) Isogamy and anisogamy
• 2) Anisogamy and oogamy
• 3) Isogamy, anisogamy and oogamy
• 4) Oogamy only

Solution

Chlorophyceae are one of the classes of green algae which show three types of sexual reproduction—isogamy, anisogamy and oogamy. 

Q52. Describe the plant body of brown algae.

Solution

The plant body of brown algae is attached to the substratum by a holdfast.   It has a stalk called stipe. The frond is a leaf-like photosynthetic organ of the plant body.

Q53. Gemma for vegetative reproduction occurs in which of the following plants?  

• 1) Marchantia  
• 2) Fern  
• 3) Funaria  
• 4) Riccia  

Solution

Gemma are the green buds in Funaria that develop along the axis of the leaves. They help in vegetative reproductive. When gemma detach from the parent plant, they develop into a new Funaria.  

Q54. Holdfast, stipe and frond constitute the plant body in case of  

• 1) Chlorophyceae  
• 2) Rhodophyceae  
• 3) All of the above  
• 4) Phaeophyceae  

Solution

In Phaeophyceae, the plant body is attached to the substratum by holdfast. The stalk is known as stipe. The frond is a leaf-like photosynthetic organ.              

Q55. Define flower.

Solution

A flower is a special reproductive structure in angiosperms in which the pollen grains and ovules develop.

Q56. Ulothrix filaments produce 

• 1) Heterogametes
• 2) Basidiospores
• 3) Isogametes
• 4) Anisogametes

Solution

Ulothrix is a green alga which reproduces sexually by the union of isogametes which are motile, biflagellate and morphologically similar gametes. Approximately 8-32 isogametes are produced from a mother cell. 

Q57. Define the following terms: 1. Isogamous fusion 2. Anisogamous fusion 3. Oogamous fusion

Solution

1. Isogamous fusion: Fusion between two gametes of similar size is called isogamous fusion.   2. Anisogamous fusion: Fusion between two gametes which are dissimilar in size is called anisogamous fusion.   3. Oogamous fusion: Fusion between one large, non-motile female gamete and a smaller, motile male gamete is called oogamous fusion.

Q58. Which plant group produces spores and embryos but lacks vascular tissues and seeds? 

Solution

Bryophytes consist of a thalloid body and are attached by hair-like structures called rhizoids. These lack vascular tissue and require water at the time of fertilisation. The haploid gametophyte (formation of spores for sexual reproduction) alternates with the diploid sporophyte (formation of spores for asexual reproduction). 

Q59. Name the pigment present in the members of Rhodophyceae.

Solution

R-phycoerythrin

Q60. Distinguish between haplontic and diplontic life cycles.  

Solution

Haplontic Life Cycle     Diplontic Life Cycle     Gametophytic phase is dominant.   Sporophytic phase is dominant.   Sporophyte is in the form of a diploid zygote.   Gametophyte is single celled or few celled.      

Q61. Draw diagrams of a) Volvox b) Chara  

Solution

a) Volvox:   b) Chara:

Q62. What is protonema?

Solution

Protonema is the first stage in the gametophytic phase of a moss.

Q63. Which ones are non-vascular?

• 1) Pteridophytes
• 2) Angiosperms
• 3) Bryophytes
• 4) Gymnosperms

Solution

Bryophytes are non-vascular plants. They possess conducting strands for the absorption of water and minerals.

Q64. What are sporophylls?

Solution

Sporophylls are leaf-like appendages in pteridophytes which bear sporangia.

Q65. Name two algae used to prepare agar.

Solution

Gelidium and Gracilaria

Q66. What is unique about bryophytes?  

• 1) Sporophyte remains attached to gametophyte.  
• 2) They do not have roots.  
• 3) Bryophytes produce spores.  
• 4) They lack vascular tissues.  

Solution

Sporophytes remain attached to the gametophyte. Gametophytes are photosynthetic and nourish the sporophytes.  

Q67. Name the diploid phase in the plant with a haplontic life cycle.  

Solution

The zygote is the diploid phase in a plant with a haplontic life cycle.  

Q68. Ribbon-shaped chloroplasts occur in  

• 1) Chlamydomonas  
• 2) Spirogyra  
• 3) Riccia  
• 4) Ulothrix  

Solution

Spirogyra is the name of the genus which is derived from its spiral shaped chloroplasts.  

Q69. Which of the following is called amphibians of the plant kingdom?

• 1) Algae
• 2) Pteridophytes
• 3) Bryophytes
• 4) Gymnosperms

Solution

Though bryophytes grow on damp soil, rocks, walls, on the banks of ponds, on the bark of trees, they require a layer of water on the surface of soil for the following reasons: Movement of male gametes to reach archegonia For the dehiscence of antheridia Because they lack conducting tissues, they require free water for absorption

Q70. State the uses of algae

Solution

Uses of algae: Algae help to increase the level of dissolved oxygen in their immediate environment. Species of algae such as Porphyra, Laminaria and Sargassum are used as food. Hydrocolloids produced by algin and carrageen are used commercially. Commercial product agar is obtained from certain species of algae. Examples: Gelidium and Gracilaria Agar is used in the preparation of ice creams and jellies. It is also used to grow microbes in laboratories. Species such as Chlorella and Spirulina are rich in proteins and thus used as food supplements.

Q71. Define pollination.

Solution

Pollination is the transfer of pollen grains, after their dispersal, from the anthers to the stigma of the pistil of the same flower or different flower of the same species.

Q72. Name the dominant phase in a plant with a haplontic life cycle.

Solution

The gametophyte is the dominant phase in a plant with a haplontic life cycle.

Q73. The first vascular plants are which of the following plants?

• 1) Bryophyta
• 2) Pteridophyta
• 3) Spermatophyta
• 4) Thallophyta

Solution

Pteridophytes are considered first seedless, terrestrials vascular plants containing xylem and phloem.

Q74. Name any two algae which exhibit a haplodiplontic life cycle.

Solution

Ectocarpus, Polysiphonia

Q75. Write the components of the cell wall of Rhodophyceae and Phaeophyceae.

Solution

Group of algae Components of cell wall Rhodophyceae Cellulose, pectin and polysulphate esters Phaeophyceae Cellulose and algin  

Q76. Name an alga which shows the diplontic life cycle.

Solution

Fucus

Q77. Name the process by which haploid spores are produced by the sporophyte.

Solution

Meiosis

Q78. Distinguish between monocotyledons and dicotyledons.

Solution

Monocotyledons Dicotyledons 1. Seeds have single cotyledon. 1. Seeds have two cotyledons. 2. Leaves show parallel venation. 2. Leaves show reticulate venation.  

Q79. State any one feature of conifers which helps to reduce water loss.

Solution

Presence of sunken stomata.

Q80. Describe the events which occur during the life cycle of an angiosperm.  

Solution

During pollination, the pollen grains germinate on the stigma.     This results in the formation of pollen tube which grows through the style and reaches the ovule.     When the pollen tube enters the sac, two male gametes are discharged.     One male gamete fuses with the egg cell and forms a zygote.     The second male gamete fuses with the diploid secondary nucleus and produces the triploid primary endosperm nucleus (PEN).     Because the fusion occurs twice, it is called double fertilisation.     The zygote develops into an embryo, while the primary endosperm nucleus develops into endosperm.     The endosperm provides nourishment to the developing embryo.     The synergids and antipodals of the egg apparatus degenerate after fertilisation.     At the end of this cycle, ovules develop into seeds which give rise to a new plant (sporophyte) while ovaries develop into fruits.  

Q81. Which plant is commonly known as maiden hair fern?

Solution

Adiantum is commonly known as maiden hair fern. 

Q82. What are coralloid roots?

Solution

Coralloid roots are specialised roots found in Cycas which are associated with nitrogen-fixing cyanobacteria.

Q83. Write any two differences between Chlorophyceae and Rhodophyceae.  

Solution

Chlorophyceae     Rhodophyceae     1. Food is stored in the form of pyrenoids.     1. Food is stored in the form of floridean starch.     2. Chlorophyll a and b are present.     2. Red pigment called r-phycoerythrin is present.        

Q84. Give any two examples of plants which exhibit a haplontic life cycle.

Solution

Chlamydomonas and Spirogyra

Q85. Explain how Laminaria is different from Porphyra.  

Solution

Laminaria     Porphyra     It is a brown alga and belongs to the group Phaeophyceae.   It is a red alga and belongs to Rhodophyceae.   Food is stored in the form of mannitol.   Food is stored in the form of floridean starch.   Pigments present are chlorophyll a, chlorophyll b, carotenoids and fucoxanthin.   Pigment present is r-phycoerythrin.   Sexual reproduction may be isogamous, oogamous or anisogamous.   Sexual reproduction is oogamous.   Gametes possess flagella.   Gametes do not possess flagella.      

Q86. Describe the structure of the vegetative cell of Chlorophyceae.  

Solution

The vegetative cell has a cell wall made of cellulose.     The cell wall is covered with a gelatinous coating of algin.     The protoplast of vegetative cells contains plastids, vacuole and nucleus.  

Q87. Draw a labelled diagram of the lifecycle of an angiosperm.  

Solution

Lifecycle of an angiosperm: