Diversity in Living World
- Which of the following are found in extreme saline conditions ? Answer: 4. Archaebacteria Archaebacteria live in harsh habitats: extreme halophiles in very salty places, thermoacidophiles in hot springs,... 1
- Which among the following are the smallest living cells, known without a definite cell wall, pathogenic to plants as well as animals and can survive without oxygen ? Answer: 2. Mycoplasma The description fits Mycoplasma. Smallest living cells. No cell wall, so they are pleomorphic. Pathogenic to plants an... 1
- Life cycle of Ectocarpus and Fucus respectively are : Answer: 2. Haplodiplontic, Diplontic Ectocarpus is a brown alga with alternation of generations, so its life cycle is haplodiplontic. Fucus... 1
- An example of colonial alga is : Answer: 1. Volvox Key idea: Colonial algae have a fixed number of cells living together as one unit. Volvox forms a spherical colony of many... 1
- Study the four statements (A-D) given below and select the two correct ones out of them :A. Definition of biological species was given by Ernst Mayr.B. Photoperiod does not affect reproduction in plants.C. Binomial nomenclature system was given by R.… Answer: 2. A and D A: Ernst Mayr gave the biological species concept. True. B: Photoperiod affects flowering and reproduction in plants. Fal... 1
- Select the wrong statement. Answer: 4. The walls of diatoms are easily destructible. Diatom cell walls are made of silica and are indestructible, so statement 4 is wron... 1
- Which one of the following is wrong for fungi? Answer: 1. All fungi possess a purely cellulosic cell wall. Fungal cell walls are made of chitin and other polysaccharides, not purely cellu... 1
- Methanogens belong to Answer: 1. Archaebacteria Methanogens produce methane under anaerobic conditions (for example in the gut of ruminants and in biogas plants)... 1
- Conifers are adapted to tolerate extreme environmental conditions because of Answer: 2. thick cuticle Conifers grow in cold, dry conditions. A thick cuticle and sunken stomata, with needle-like leaves, reduce water lo... 1
- Which one of the following statements is wrong ? Answer: 1. Algin is obtained from red algae, and carrageenan from brown algae. The statement is reversed. Algin comes from brown algae and c... 1
- The label of a herbarium sheet does not carry information on Answer: 3. height of the plant A herbarium label records the collector's name, date, locality, local name, family and scientific name, habit... 1
- Select the mismatch. Answer: 1. Large central vacuoles—Animal cells Large central vacuoles are a feature of mature plant cells, not animal cells. Animal cells ha... 1
- Select the wrong statement. Answer: 1. Pili and fimbriae are mainly involved in motility of bacterial cells. Pili and fimbriae are surface structures used for attachmen... 1
- Chrysophytes, Euglenoids, Dinoflagellates and Slime moulds are included in the kingdom : Answer: 2. Protista Chrysophytes (diatoms), euglenoids, dinoflagellates, slime moulds and protozoans are unicellular eukaryotes placed in Ki... 1
- Select the correct statement: Answer: 3. Sequoia is one of the tallest trees Sequoia (the redwood, a gymnosperm) is among the tallest trees, so option 3 is correct. 1: Gy... 1
- In bryophytes and pteridophytes, transport of male gametes requires : Answer: 4. Water In bryophytes and pteridophytes the male gametes (antherozoids) are flagellated and swim through water to reach the egg, so... 1
- Nomenclature is governed by certain universal rules. Which one of the following is contrary to the rules of nomenclature ? Answer: 1. Biological names can be written in any language Biological names must be in Latin (or Latinised) form, whatever the language of t... 1
- One of the major components of cell wall of most fungi is : Answer: 1. Chitin Key idea: The fungal cell wall is made mostly of chitin (a polymer of N-acetylglucosamine) and polysaccharides. Peptidogly... 1
- Which one of the following statements is wrong ? Answer: 3. Eubacteria are also called false bacteria. Key idea: Eubacteria are the true bacteria, not 'false' bacteria. Cyanobacteria are bl... 1
- Which of the following statements is wrong for viroids ? Answer: 4. Their RNA is of high molecular weight Key idea: Viroids are infectious agents made only of a small, free RNA with no protein coat... 1