IGCSE Biology Paper-1: Specimen Questions with Answers 190 - 191 of 208

Question 190

Edit

Question

MCQ▾

Following given diagram is showing gaseous exchange.

Gases are Exchanged

Gases Are Exchanged

Loading image

Which of the following gases are exchanged here?

Choices

Choice (4)
a.O2 and CO2
b.N2 and NO2
c.CO2and O2
d.N2 and CO2

Answer

a.

Explanation

The purpose of the respiratory system is to perform gas exchange. Pulmonary ventilation provides air to the alveoli for this gas exchange process. At the respiratory membrane, where the alveolar and capillary walls meet, gases move across the membranes, with oxygen entering the bloodstream and carbon dioxide exiting. It is through this mechanism that blood is oxygenated and carbon dioxide, the waste product of cellular respiration, is removed from the body.

The purpose of the respiratory system

The Purpose of the Respiratory System

Loading image

Question 191

Edit

Question

MCQ▾

The diagram shows a simplified water cycle.

Water in the Soil

Water in the Soil

Loading image

Which processes are represented by arrow are Correct?

Choices

Choice (4)
a.transpiration-3, precipitation-1, respiration-2
b.transpiration-1, precipitation-3, respiration-2
c.transpiration-2, precipitation-3, respiration-1
d.transpiration-1, precipitation-2, respiration-3

Answer

c.

Explanation

Water in the Soil

Water in the Soil

Loading image

The Water Cycles

The water cycle is different from other cycles because only a tiny proportion of the water that is recycled passes through living organisms. Animals lose water by evaporation, defecation, urination, and exhalation. They gain water from their food and drink. Plants take up water from the soil and lose it by transpiration. Millions of tonnes of water are transpired, but only a tiny fraction of this has taken part in the reactions of respiration or photosynthesis. The great proportion of water is recycled without the intervention of animals or plants. The Sun shining and the wind blowing over the oceans evaporate water from their vast, exposed surfaces. The water vapour produced in this way enters the atmosphere and eventually condenses to form clouds. The clouds release their water in the form of rain or snow (precipitation).