PART - 1 - Unit I : CH - 2 Biological Classification — BIOLOGY STD 11 Science — Question

Draw a labelled diagram of the schematic view of human respiratory system. Write any four differences between right lung and left lung.

Describe the following: (i) Synapsis, (ii) Bivalent (iii) Chiasmata.

Bryophyta (bryophytes) A division of plants which for some authors includes the mosses (Musci) and liverworts (Hepaticae), but is now often taken to include only the mosses; liverworts having been assigned divisional status as Hepatophyta. Bryophytes differ from algae in that the multicellular gametangium is surrounded by a protective jacket of sterile cells; gametangia of algae are usually unicellular and never have a protective jacket of sterile cells. Although bryophytes lack differentiated water-conducting vessels, and rely largely or entirely on water absorbed from rain falling on the plants, or from a moist atmosphere, some larger species may have simple water-conducting cells. They lack true roots, but possess root-like rhizoids which anchor them to a substrate and which can absorb water and minerals. The plants all show a heteromorphic alternation of generations, with a green vegetative gametophyte (the familiar moss or liverwort plant) and a sporophyte which typically takes the form of a (usually stalked) capsule and which is partially or wholly parasitic on the gametophyte. Most bryophytes are land plants and are found worldwide in a range of habitats. They are known from Devonian rocks, but there is no evidence to link them with either the green algae or the more advanced pteridophytes.

(1) A characteristic feature of bryophytes is:
(a) a dominant and parasitic sporophyte
(b) a dominant and spore-producing gametophyte
(c) a small sporophyte phase, which is dependent on the gametophyte
(d) sporophytes stay for a longer duration.

(2) Find the true statement about bryophytes:
(a) they have chloroplasts
(b) they have archegonia
(c) they are thalloid
(d) all of the above.

(3) Among the following which is not characteristics feature of bryophyte:
(a) Motile sperms
(b) Presence of archegonium
(c) Water essential for fertilization
(d) Independent sporophyte

(4) Bryophytes differ from pteridophytes in:
(a) Swimming antherozoids
(b) An independent gametophyte
(c) Archegonia
(d) Lack of vascular tissue

(5) In bryophytes, antherozoids are-
(a) Biflagellate
(b) Multiflagellate
(c) Sometimes biflagellate and sometimes multiflagellate.
(d) Biflagellate in a few species and multiflagellate in the rest.

Alex used to go to vegetable market with his grandfather, a retired biology teacher. Grandfather told Alex that brinjal, chillies and tomato belong to the same family of plants and asked him to find out the similarity in these plants. Alex found that it's a large family, commonly called as the ' potato family'. Plants belonging to this family are mostly herbs, shrubs and rarely small trees. Many plants belonging to this family are source of food, spice, medicine, fumigatory, and ornamental.

(1).The name of this family is
(a) Solanaceae  (b) Fabaceae  (c) Liliaceae  (d) Brassica ear.

(2). Fruits of this family are known as
(a) Berry or capsule  (b) Legume  (c) Endosperm  (d) Cotyledon.

(3). Aestivation in calyx and corolla of this family is
(a) Valvate  (b) Imbricate  (c) Twisted  (d) Vexillary.

(4). Stamens of the flowers belonging to this family are mostly attached with petals.This condition is known as
(a) Epipetalous  (b) Epiphyllous  (c) Polyandrous  (d) Monoadelphous

(5). Medicinal plants belonging to this family are
(a) Belladonna, Ashwagandha
(b) Aloe, Asparagus
(c) Tobacco, Petunia
(d) Muliathi, Spice.

In addition to proteins, viruses also contain genetic material, that could be either RNA or DNA. No virus contains both RNA and DNA. A virus is a nucleoprotein and the genetic material is infectious. In general, viruses that infect plants have single stranded RNA and viruses that infect animals have either single or double stranded RNA or double stranded DNA. Bacterial viruses or bacteriophages (viruses that infect the bacteria) are usually double stranded DNA viruses. The protein coat called capsid made of small subunits called capsomeres, protects the nucleic acid. These capsomeres are arranged in helical or polyhedral geometric forms. Viruses cause diseases like mumps, small pox, herpes and influenza. AIDS in humans is also caused by a virus. In plants, the symptoms can be mosaic formation, leaf rolling and curling, yellowing and vein clearing, dwarfing and stunted growth.

(1) Viruses are made up of:
(a) Proteins & DNA
(b) Proteins only
(c) Proteins & RNA
(d) Proteins & DNA / RNA

(2) Bacteriophages are usually :
(a) Single stranded DNA viruses
(b) Double stranded RNA viruses
(c) Double stranded DNA viruses
(d) Single stranded RNA viruses

(3) Which is not a viral disease of humans:
(a) Pneumonia (b) Herpes (c) Mumps (d) Smallpox

(4) Select the incorrect statement regarding Capsomeres:
(a) Capsomeres are sub-units of Capsid
(b) Capsomeres are made of peptidoglycans
(c) Capsomeres may be arranged in helix or polyhedron
(d) Capsomeres are made of proteins

(5) Which of these is not a symptom of viral infection in crops:
(a) Leaf rolling (b) Curling of leaf (c) Decay of roots (d) Vein clearing

Can you identify the correct sequence of taxonomical categories?

1. Species → Order → Phylum → Kingdom
2. Genus → Species → Order → Kingdom
3. Species → Genus → Order → Phylum

Write four differences between lined and unlined sutures.

Try to collect all the currently accepted meanings for the word ‘species’. Discuss with your teacher the meaning of species in case of higher plants and animals on one hand, and bacteria on the other hand.