41. Most of the time, species are identified by their appearance. Why?
(a) If two organisms look alike, they must be the same species
(b) This is the criterion used to define a biological species
(c) If two organisms look different, they must be different species
(d) This is the most convenient way of identifying species
42. A new species can arise in a single generation
(a) through geographical isolation
(b) in a very large population that is spread over a large area
(c) if a change in chromosome number creates a reproductive barrier
(d) if allopatric speciation occurs
43. The evolution of numerous species, such as Darwin’s finches, from a single ancestor is called
(a) adaptive radiation (b) sympatric speciation
(c) gradualism (d) nondisjunction
44. According to the _________ model, evolution occurs in spurts; species evolve relatively rapidly, then remain unchanged for long periods.
(a) nondisjunction (b) gradualist
(c) adaptive radiation (d) punctuated equilibrium
45. Sympatric speciation is
(a) the appearance of a new species in the same area as the parent population.
(b) initiated by the appearance of a geographical barrier
(c) the emergence of many species from a single ancestor
(d) especially important in the evolution of island species
46. In some animals eg. Axolatal larvae of Ambystoma, the larvae fails to undergo metamorphosis (iodine deficiency). It develops gonads, attains sexual maturity and start reproduction. This is called-
(a) Parthenogenesis (b) Neoteny or paedogenesis
(c) Retrogress metamorph (d) Stagnant metamorphosis
47. Darwin finches from various islands of Galapagos island differed in size and shape of bill due to-
(a) Mutation (b) Adaptive radiation
(c) Competition (d) Gene migration
48. The enzyme which is occurs in all eukaryotes and show great homology is-
(a) Cytochrome oxidase (b) Cytochrome c
(c) Cytochrome b (d) Cytochrome a
49. The hormone which is almost identical and occurs in all vertebrates is-
(a) Insulin (b) Thyroxine
(c) Glucagon (d) ACTH
50. The phylogenictically closed relative of humans are-
(a) Langurs (b) Apes
(c) Mokeys (d) Shrews
Answer
41. (d) 42. (c) 43. (a) 44. (d) 45. (a) 46. (b) 47. (b) 48. (b) 49. (b) 50. (b)
