Explore topic-wise InterviewSolutions in .

Right OPTION is (a) Cyst

To explain I would SAY: During unfavourable conditions, an outer layer that is formed OUTSIDE chlamydomonas is called cyst. These unfavourable conditions allow MULTIPLE fission inside the cyst.

Right CHOICE is (a) plants that don’t have well-DIFFERENTIABLE structure

For explanation I would say: Plants are classified as Thallophyta and others BASED on their well differentiable structure. Plants WHOSE structure can’t be differentiated are put under the category of “Thallophyta”.

The correct choice is (a) Morphological characteristics

Easiest EXPLANATION: Artificial CLASSIFICATION is based on morphological structures of the PLANT i.e. artificial classification focuses on EXTERNAL structure of the plants than their internal structure.

Right choice is (b) False

The explanation is: A fertilized embryo takes several years to mature and form seeds in the CASE of Gymnosperms. Polyembryogeny is very COMMON in case of Gymnosperms.

The CORRECT answer is (a) Pteridophytes

To explain I would SAY: Pteridophytes are the first ever evolved plants with vascular tissue in them i.e. they contain xylem and PHLOEM. As they contain vascular TISSUES, they are capable of growing several METERS tall.

Right answer is (a) SPERMATOPHYTA

The explanation is: Gymnosperms (GYMNO = Naked, spermae = SEEDS) and Angiosperms (Angio = Covered, spermae = seeds) are together called as Spermatophyta (Spermae = seeds, phyta = plants).

Right option is (b) ARCHEGONIUM

The best I can explain: The female sex organs in bryophytes are CALLED archegonium and they produce female GAMETE called egg. The male sex organ is called ANTHERIDIUM and produce male gametes called ANTHEROZOIDS.

Right OPTION is (c) In Spirogyra, DIPLOID SPOROPHYTE is the dominant phase

Explanation: Haploid gametophyte is the dominant phase in BRYOPHYTES and in volvox. ALSO, in Spirogyra, the diploid Sporophyte is the dominant phase. In Pappaya, haploid gametophyte is the dominant phase.

The correct answer is (b) AIR sac

To EXPLAIN: Pollen grains are dispersed to different parts of the world through air, WATER and INSECTS. They are equipped with wings (some don’t have wings) and are COVERED with an air sac.

Correct CHOICE is (d) Microsporangiate and macrosporangiate exists within the same plant

Easiest explanation: Sporophylls are spirally ARRANGED to form strobili. Microsporophylls are spirally arranged to form Strobili to form a cone shaped STRUCTURES called microsporangiate or male strobili. Microsporangiate is ALSO called as male strobili because they contain microspores that form male gametophyte. GAMETOPHYTES can’t exist independently i.e. free living. Microsporangiate and macrosporangiate might exists within the same plant or mayn’t.

The correct answer is (a) CAPSULE

For explanation I would say: Sporophyte contains mainly of three parts capsule, seta and foot. Capsule is the PORTION of sporophyte that bears spores and seta is the PART that transfers WATER and nutrients from gametophyte to capsule.

Correct OPTION is (a) True

Explanation: The color in PHAECOPHYCEAE DEPENDS on the amount of XANTHOPHYLLS and fucoxanthin. Their COLORS vary from olive green to different shades of brown depending on the amount of pigments present.

Correct ANSWER is (b) Egg

Easy explanation: The MALE gamete in sexual reproduction of algae is CALLED antherozoid and the FEMALE gamete is called egg. These two gametes FUSE to form a zygote which will further develop to form spores.

Right CHOICE is (a) True

Explanation: Plants other than that of Thallophyta are classified BASED on the PRESENCE or absence of vascular tissues as Bryophyta and others. Plants are further classified based on their presence of SEED and their seed cover.

The correct choice is (d) EVERY CELL contains chlorophyll in them

Explanation: Ulothrea are multicellular filamentous algal.Ulothrea contains three DIFFERENT sets of cells i.e. apical, basal and lateral cells. Apical cells are rounded at one end WHEREAS basal cells are elongated at one end. Every cell contains chlorophyll except basal cell contains chlorophyll in them.

Right choice is (d) Every megaspore that is produced after MEIOSIS UNDERGOES mitosis to form a female gametophyte

For explanation: On reaching female gametophyte, the pollen grains produce a tube like structure that carries sperms to the egg. Fertilization in Gymnosperms can also be described as siphonogamic. Ovules in Gymnosperms are unprotected unlike that of angiosperms. Among the four MEGASPORES that are formed after meiosis only one megaspore is functional and the rest becomes DEFUNCT.

Correct answer is (b) branched stem

Easiest EXPLANATION: The leaves of cedrus tree are small and have LITTLE surface are. Their leaves are COMPOUND in nature. They have mycorrhizal root SYSTEM. Unlike cycas, stems in cedrus are branched.

The correct choice is (b) Bryophytes are mostly found in dry hilly AREAS

To EXPLAIN: Bryophytes are sub-classified into liverworts and mosses. Bryophytes are mostly found in moist hilly areas. Bryophytes don’t contain vascular TISSUES to transmit water and therefore don’t GROW tall. Bryophytes follow CRYPTOGAMAE.

Correct option is (a) Frond

To explain I would say: The vegetative cells in Phaecophyceae are made up of two layers with the INNER one being made of cellulose and the other being made of gelatinous coating of algin. A leaf like PHOTOSYNTHETIC organ in Phaecophyceae is called as frond. They ALSO have a stalk called STIPE and a substratum called as holdfast.

The correct CHOICE is (b) Multiple FISSION takes place under suitable conditions

To elaborate: Multiple fission is a process through which many individuals are produced by REPEATED NUCLEAR division. Multiple fission takes place under unfavourable conditions. During multiple fission, an outer layer called cyst is formed.Nucleus DIVIDES repeatedly and new individuals are formed inside the cyst after which cyst breaks to release new individuals.

Correct answer is (C) Evolutionary RELATIONSHIPS

Easy explanation: Phylogenetic classification considers evolutionary relationships between organisms. Fossil RECORDS, cytotaxonomy, chemotaxonomy and numerical taxonomy HELP in studying their evolutionary structures.

Right answer is (c) Gemmae

Easy explanation: In fragmentation, leaves/ stems FALL off accidently and grow to form NEW individuals. Budding is a PROCESS in which an outgrowth develops and splits from the parent thallus to produce new individual. Thallus has structures called gemmae cups that CONTAIN gemmae which in turn reproduce to form new individual. Sporophyte develops from a developed embryo and results in the formation of spores. Therefore, sporophyte formation is a SEXUAL process that involves two gametes.

The CORRECT option is (a) Pyrenoids

The EXPLANATION is: In CHLOROPHYCEAE, chloroplasts contain storage bodies CALLED Pyrenoids. Pyrenoids consists of proteins and starch. Chlorophyceae sometimes store food as oil DROPLETS.

Correct ANSWER is (a) True

To EXPLAIN: In coralloid roots, roots are short and IRREGULARLY arranged and exist in symbiotic association with cyanobacteria. Cyanobacteria HELP in fixing of Nitrogen and at the same time manage to get shelter in the rots.

Correct choice is (B) False

For explanation: Strobili or cone is a cone-shaped structure found in some of the PTERIDOPHYTES. These are formed by sporophyll and are found in many of the conifers PLANTS like EQUISETUM and Selaginella.

The correct CHOICE is (B) Mosses contain an intermediary stage CALLED protonema which is absent in LIVERWORTS

Explanation: Mosses grow into an intermediary stage from spores called protonema after which they grow into leafy like THALLUS. Whereas, in liverworts this intermediary stage is absent i.e. the spores develop into thallus without protonema.

Correct option is (C) Structure of branches

The BEST EXPLANATION: PLANTS are sub-classified based on their well-differentiable structure, presence of vascular tissues, presence of seeds, seed coat i.e. if the seeds are naked or covered.

The correct option is (b) ULVA

Explanation: Ulva is a multicellular ALGAL that grows on moist rocks and walls. It is edible and is used as salad leaves. It is also called as sea lettuce. It has 2 layers of IRREGULARLY arranged cells.

The correct choice is (d) Numerical taxonomy gives the same result irrespective of the DIFFERENT sets of characteristics considered

Easiest EXPLANATION: Numerical CLASSIFICATION is based on mathematical calculations based on observable characteristics. In this mode of classification, each character is given a number or a code. The more the number of similar characters, the more is the chance that they belong to similar taxon. The main DISADVANTAGE of numerical taxonomy COMES with the variation in result with variation in set of characteristics.

Correct option is (a) CELL wall

To EXPLAIN: Plant cells contain an extra LAYER outside their cell membrane called cell wall. Cell wall plays a major role in the metabolic activities of a plant cell. It HELPS in controlling of osmotic PRESSURE.

Right answer is (c) Sexual organs are given more preference than vegetative organs

To EXPLAIN: Artificial classification is the oldest mode of classification in plantae KINGDOM. This classification LAID the FOUNDATION for classification in plants. Artificial classification classifies closely related species under one category. However, in this mode of classification vegetative and sexual characteristics are given equal preference.

The correct choice is (a) Integument

To elaborate: The covering outside an ovule in Gymnosperms is called integument. It has a tiny hole at ONE end that ALLOWS GERMINATION of pollen grains that are carried to female GAMETOPHYTE through air and water.

The CORRECT option is (b) Nucellus

Best explanation: Megasporangium in Gymnosperms is also called as Nucellus. It contains MEGASPORES or macrospores which gives rise to a FEMALE gametophyte or ARCHEGONIUM after mitosis.

Right option is (d) Zoo-SPORES are non-motile and flagellated

To explain I would say: Most of the algae reproduce USING spore formation. Asexual spores are called as zoo-spores and the reproductive part in algae is called zoosporangium. Under favourable conditions, these organisms germinate to FORM NEW organism. Zoo-spores are motile and flagellated.

Right answer is (B) Cellulose

For explanation I would say: Spirogyra contains two cellular layers. The outer cellular layer is MADE of Pectin. The INNER cellular in spirogyra is made up of Cellulose. This double cellular LAYERED STRUCTURE helps them to withstand osmotic pressure.

Right answer is (b) False

Best explanation: Blue green algae or cyano-bacteria belong to the kingdom of Monera and FALLS under the CATEGORY of EUBACTERIA. EARLIER it was thought to be a part of algae.

Right answer is (a) True

Best EXPLANATION: MUSHROOM, few other fungi and blue-green ALGAE which were earlier considered to be plants are now put under different kingdoms. MUSHROOMS BELONG to the kingdom fungi and blue-green algae or cyanobacteria are classified under Monera.