IGCSE Biology Paper-1: Specimen Questions with Answers 161 - 162 of 208

Question 161

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Question

MCQ▾

Which organisms remove carbon dioxide from the atmosphere?

Choices

Choice (4)
a.Consumer
b.Herbivores
c.Decomposers
d.Producers

Answer

d.

Explanation

  • Producers: Green photosynthetic plants entrap solar energy through chlorophyll to synthesize organic food from inorganic raw materials and are called autotrophs (self-nourishing).
  • Major producers in terrestrial ecosystem are herbaceous and woody plants.
  • Major producers in aquatic ecosystem are phytoplankton’s, algae and the floating, submerged, and marginal plants found at the edges.
  • Producers convert solar energy into chemical energy stored in the bonds of sugars, hence are also known as “converters” or “transducers. “

Question 162

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Question

MCQ▾

A natural method of birth control assumes that sperms live for three days after intercourse, ovulation occurs between days 13 - 15 of the menstrual cycle and released ova live for 36 hours.

On which day of the cycle should intercourse not result in pregnancy?

Choices

Choice (4)
a.day 15
b.day 11
c.day 6
d.day 13

Answer

c.

Explanation

Ovulation happens about 14 days before your period starts. If average menstrual cycle is 28 days, female ovulate around day 14, and these are her most fertile days are days 12,13 and 14.

Infertile Days Cycle

Infertile Days Cycle

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