IGCSE Biology Paper-1: Specimen Questions with Answers 146 - 147 of 208

Question 146

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Question

MCQ▾

A nail is driven into the trunk of a 30-year-old tree at a point 1 meter above the soil level. The tree grows in height at the rate of 0.5 meters a year. After three years, the nail will be

Choices

Choice (4)
a.1.5 meters above the soil
b.2 meters above the soil
c.1 meter above the soil
d.2.5 meters above the soil

Answer

c.

Explanation

  • In plants growth take place at the apical region. The plant growth is carried out by meristematic tissue. So, at the trunk region, the height does not increase as a nail is inserted in tree trunk, at that point where permanent growth occurs.

Question 147

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Question

MCQ▾

Which of the following animal shown here is Not an Amphibian?

An Amphibian

An Amphibian

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Choices

Choice (4)
a.D
b.A
c.B
d.C

Answer

c.

Explanation

Features of Amphibians

  • Nonmarine, but are either terrestrial/amphibious or freshwater forms
  • The body is differentiated into Head, Trunk and Tail (The ‘neck’ is absent in all amphibians). However, in most of the terrestrial or amphibious forms the tail is also, absent.
  • Cold blooded or Poikilothermic
  • Undergo aestivation (summer sleep) or hibernation (winter sleep)
  • Alimentary canal has cloacal opening
  • Kidney- Mesonephros type (mostly ureotelic)
  • Respiration- Cutaneous, Branchial or Pulmonary
  • Heart – 3-chambered with sinus venosus, BVS – closed type and the Systemic arch is paired. Both renal and hepatic portal systems well developed.
  • Exoskeleton lacking in most of the forms
  • Dioceses (unisexual), fertilization mostly external
  • Oviparous, extra-embryonic membranes absent.

Examples: - Uraeotyphlus (Blind worm) and Ichthyophis, Ambyostoma (Salamander) - larva called Axolotl shows neoteny (Retention of larval characters in adults) and Paedogenesis (reproduce in larval stages) in the deficiency of iodine; Necturus (Mud puppy), Siren (Mud eel), Triturus (Newt), Amphiuma (Congo eel), Proteus (Blind Salamander) Rana tigrina (Indian Bull frog), R. pipiens (Leopard frog), Bufo (Toad), Alytes (Mid-wife toad) - shows parental care, Hyla (Tree frog) and Rhacophorus (Flying frog), Pipa (Surinam Toad), Bombinator (Fire bellied Toad), Xenopus.