Recent questions tagged class11

Class – Amphibia : 1. Sexes are separate. 2. Fertilisation is external. 3. They are viviparous 4. Development is direct. Regarding 1,2,3 and 4:

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Class – Amphibia : 1. Alimentary canal, urinary and reproductive tracts open into a common chamber called cloaca 2. Cloaca opens to the exterior. 3. These are cold-blooded animals. Regarding 1,2 and 3:

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Class – Amphibia : 1. The amphibian skin is dry. 2. They do not have scales. 3. They don't have eyelids. Regarding 1,2 and 3:

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Class – Amphibia : 1. Most of them have two pairs of limbs. 2. Body is divisible into head and trunk. 3. Tail may be present in some. Regarding 1,2 and 3:

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Class – Osteichthyes : 1. Sexes are separate. 2. Fertilisation is usually internal. 3. They are mostly oviparous 4. Development is direct. Regarding 1,2,3 and 4:

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Class – Osteichthyes : 1. Air bladder is present 2. Air bladder regulates buoyancy (if present in any aquatic organism). 3. Heart is two- chambered 4. Heart has one auricle and one ventricle. Regarding 1,2,3 and 4:

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Class – Chondrichthyes : 1. Teeth are modified placoid scales 2. Teeth are directed forwards. 3. Their jaws are very powerful. 4. These animals are predaceous. Regarding 1,2,3 and 4:

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Regarding Class – Chondrichthyes : 1. They are marine animals 2. They have streamlined body 3. They have cartilaginous exoskeleton Regarding 1,2 and 3:

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Regarding Class – Cyclostomata : 1. Cyclostomes are marine 2. But they migrate to fresh water for spawning . 3. After spawning, they die within a few days. Regarding 1,2 and 3:

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Regarding Class Cyclostomata : 1. They have paired fins 2. Their body is devoid of scales. 3. Cranium and vertebral column are bony. 4. Circulation is of closed type Regarding 1,2,3 and 4:

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Regarding Class – Cyclostomata : 1. They have an elongated body 2. They bear 6-15 pairs of gill slits. 3. Cyclostomes have a circular mouth without jaws Regarding 1,2 and 3:

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1. Agnatha includes Class Cyclostomata. 2. Tetrapoda includes Pisces, Amphibia, Reptilia, Aves and Mammals 3. Pisces includes Chondrichthyes and Osteichthyes. Regarding 1,2 and 3:

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1. Vertebrata includes Divisions Agnatha and Gnathostomata. 2. Gnathostomata includes Super Classes Pisces and Tetrapoda. 3. Divisions Agnatha includes Class Cyclostomata. Regarding 1,2 and 3:

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Regarding vertebrates : 1. They have a ventral muscular heart with two, three or four chambers. 2. They have kidneys for excretion and osmoregulation 3. They have paired appendages which may be limbs but never fins.

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1. In Urochordata, notochord is present only in larval tail. 2. In Cephalochordata,notochord extends from head to tail region 3. In Cephalochordata,notochord is persistent throughout their life. Regarding 1,2 and 3:

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Phylum – Hemichordata : 1. Sexes are separate. 2. Fertilisation is internal. 3. Development is direct . Regarding 1,2 and 3:

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Phylum Hemichordata : 1. Circulatory system is of closed type. 2. Respiration takes place through gills. 3. Excretory organ is proboscis gland. Regarding 1,2 and 3:

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1. Hemichordata was considered as a sub-phylum under phylum Chordata earlier. 2. Now it is placed as a separate phylum under non-chordata. 3. This phylum consists of a small group of worm-like marine animals. Regarding 1,2 and 3 :

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Phylum Echinodermata : 1. Digestive system is complete 2. They have mouth on the upper (dorsal) side 3. Anus is on the lower (ventral) side. Regarding 1,2 and 3:

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In Mollusca : 1. The posterior head region has sensory tentacles. 2. The mouth contains a file-like rasping organ for feeding 3. The file-like rasping organ for feeding is called morula Regarding 1,2 and 3:

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In Mollusca : 1. A soft and spongy layer of skin forms a mantle over the calcarious hump. 2. The space between the hump and the mantle is called the mantle cavity 3. In mantle cavityfeather like gills are present. Regarding 1,2 and 3:

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Regarding Molluscs : 1. Body is covered by a calcareous shell 2. Body is unsegmented 3. They have a distinct head, muscular foot and visceral hump Regarding 1,2 and 3:

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Regarding Arthropoda : 1. They are mostly ovoviviparous. 2. Development is direct. 3. Development is indirect. Regarding 1,2 and 3:

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Regarding Arthropoda : 1. It is the second largest phylum of Animalia 2. It includes insects. 3. Over one-thirds of all named species on earth are arthropods Regarding 1,2 and 3:

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In Annelida : 1. Members of phylum Annelida are dioecious. 2. Members of phylum Annelida are monoecious 3. Reproduction is sexual. Regarding 1,2 and 3:

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In Annelida : 1. A closed circulatory system is present. 2. Neural system consists of paired ganglia 3. Paired ganglia connected by lateral nerves to a single ventral nerve cord. Regarding 1,2 and 3:

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Regarding Aschelminthes: 1. Fertilisation is internal 2. Development is direct. 3. Development is indirect. Regarding 1,2 and 3:

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Regarding Aschelminthes: 1. Sexes are separate 2. They are monoecious. 3. Often females are longer than males. Regarding 1,2 and 3:

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Regarding Aschelminthes: 1. Alimentary canal is incomplete 2. They a well- developed muscular pharynx. 3. An excretory tube removes body wastes from the body cavity through the excretory pore. Regarding 1,2 and 3:

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Regarding Platyhelminthes : 1. Planaria possess high regeneration capacity. 2. Tapeworm is Taenia and it is an intestinal parasite. 3. Fasciola hepatica is Liver fluke Regarding 1,2 and 3:

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Regarding Platyhelminthes : 1. Sexes are separate. 2. Fertilisation is internal. 3. Development is through many larval stages Regarding 1,2 and 3:

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Regarding Platyhelminthes : 1. They are mostly endoparasites found in animals including human beings. 2. Hooks and suckers are present in the parasitic forms. 3. Some of them absorb nutrients from the host directly through their body surface. Regarding 1,2 and 3:

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In Ctenophores: 1. Sexes are separate. 2. Reproduction takes place only by sexual means. 3. Fertilisation is internal. 4. Development is direct Regarding 1,2,3 and 4:

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1. Cnidarians exhibit one of two basic body forms called polyp and medusa. 2. Some cnidarians which exist in both forms exhibit alternation of generation. 3. Alternation of generation is Metagenesis. 4. Polyps produce medusae sexually 5. Medusae form the polyps asexually Regarding 1,2,3,4 and 5:

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1. Cnidarians exhibit two basic body forms called polyp and medusa. 2. Polyp is a sessile and spherical form 3. Medusa is umbrella-shaped and free-swimming Regarding 1,2 and 3:

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1. Cnidarians have a central gastro-vascular cavity 2. They have a single opening, mouth or hypostome. 3. Digestion is extracellular 4. Digestion is intracellular. Regarding 1,2,3 and 4:

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In Sponges : 1. Eggs and sperms are produced by different individual. 2. Fertilisation is external 3. Development is indirect having a larval stage which is morphologically similar to the adult. Regarding 1,2 and 3:

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In Sponges : 1. Digestion is extracellular. 2. The body is supported by a skeleton made up of spicules or spongin fibres. 3. Sexes are separate Regarding 1,2 and 3:

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1. Sponges have a water transport or canal system. 2. Water enters through minute pores (osculum) in the body wall into a central cavity, spongocoel, from where it goes out through the ostia. 3. This pathway of water transport is helpful in food gathering, respiratory exchange and removal of waste. Regarding 1,2 and 3:

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1. Members of phylum - porifera are commonly known as sponges. 2. Sponges are generally marine and mostly symmetrical animals. 3. Sponges are primitive multicellular animals and have tissue level of organisation. Regarding 1,2 and 3:

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Segmentation: 1. In some animals the body is externally, but not internally divided into segments with a serial repetition. 2. The phenomenon is known as metamerism. 3. Earthworm shows this pattern called metameric segmentation. Regarding 1,2 and 3:

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Plant life cycle and alternation of generations: 1. The haploid gametophytic plant body produces gametes by mitosis. 2. Following fertilisation the zygote divides by mitosis to produce a diploid sporophytic plant body. 3. Haploid spores are produced by this plant body by meiosis. Regarding 1,2 and 3:

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1. Double fertilisation is an event unique to angiosperms and gymnosperms. 2. The zygote develops into an embryo 3. Primary endosperm nucleus (PEN) develops into endosperm which provides nourishment to the developing embryo. 4. The synergids and antipodals degenerate after fertilisation. 5. During these events the ovules develop into seeds and the ovaries develop into fruit. Regarding 1,2,3,4 and 5:

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In angiosperm : 1. After pollination, the pollen grains germinate on the stigma and the resulting pollen tubes grow through the tissues of stigma and style and reach the ovule. 2. The pollen tubes enter the embryo-sac where two male gametes are discharged. 3. One of the male gametes fuses with the egg cell to form a zygote (syngamy). 4. The other male gamete fuses with the diploid secondary nucleus to produce the triploid primary endosperm nucleus (PEN). 5. This event is termed as double fertilisation Regarding 1,2,3,4 and 5:

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In flower (of angiosperm) : 1. Each of the cells of an embryo-sac is haploid. 2. Each embryo-sac has a three-celled egg apparatus – one egg cell and two synergids, two antipodal cells and three polar nuclei. 3. The two synergids fuse to produce a diploid secondary nucleus. Regarding 1,2 and 3:

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In flower (of angiosperm) : 1. The anthers, following meiosis, produce pollen grains. 2. The embryo-sac formation preceeds meiosis. 3. Each of the cells of an embryo-sac is haploid. Regarding 1,2 and 3:

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In angiosperms : 1. The pollen grains and ovules are developed in specialised structures called flowers. 2. In angiosperms, the seeds are enclosed by fruits. 3. The angiosperms are an exceptionally large group of plants occurring in wide range of habitats. Regarding 1,2 and 3:

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In gymnosperms : 1. The pollen grain is released from the microsporangium. 2. Pollen grains are carried in air currents and come in contact with the opening of the ovules borne on megasporophylls. 3. The pollen tube carrying the male gametes grows towards archegonia in the ovules and discharge their contents near the mouth of the archegonia. 4. Following fertilisation, zygote develops into an embryo and the ovules into seeds. 5.The seeds are not covered. Regarding 1,2,3,4 and 5:

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In gymnosperms : 1. The megaspore mother cell divides mitotically to form four megaspores. 2. All the four megaspores are enclosed within the megasporangium (nucellus) develop into a multicellular female gametophyte 3. Female gametophyte bears one archegonium or female *** organ. 4. The multicellular female gametophyte is also retained within megasporangium. Regarding 1,2,3 and 4:

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In gymnosperms : 1. The megaspore mother cell is differentiated from few of the cells of the nucellus. 2. The nucellus is protected by envelopes and the composite structure is called an ovule. 3. The ovules are borne on megasporophylls which may be clustered to form the female cones. Regarding 1,2 and 3:

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