CIE Biology Paper-4: Specimen Questions 50 - 52 of 120
Question number: 50
Describe in Detail
What do you mean by artificial selection? Is artificial selection affect the natural selection
It is modification of a species by man’s intervention so that certain desirable characteristics are represented in successive generations. Human being through artificial selection has produced several species of dog, pigeons, horse and vegetables. Artificial selection affect the natural selection. Natural selection is based on appearance of variations, competence and adaptations to change in the environment. Artificial selection gives artificial environment to the selected plant and animals and it will eliminate competition adaptation or natural selection.
The graph shows rate of photosynthesis in different amount of carbon dioxide in the air. By using the graph
Question number: 51 (1 of 2 Based on Passage) Show Passage
Write in Brief
What will be the rate of photosynthesis of carbon di oxide in the air is 0.4%
Rate of photosynthesis will be 60 unit.
Question number: 52 (2 of 2 Based on Passage) Show Passage
Describe in Detail
What is the relationship between amount of carbon di oxide and the rate of photosynthesis process? What other factors affect the rate of photosynthesis.
Carbon dioxide used to make sugar in the photosynthesis reaction. An increase in the concentration of carbon dioxide gives an increase in the rate of photosynthesis. At the fix point rate falls of and at a certain carbon dioxide concentration the rate of photosynthesis stays constant at that time a rise in carbon dioxide levels has no affect on the rate of photosynthesis.
Light and temperature also change the rate of photosynthesis. The rate of photosynthesis increases when light gets brighter. The higher the temperature then the greater the rate of photosynthesis, photosynthesis is a chemical reaction and the rate of most chemical reactions increases with temperature. However, for photosynthesis at temperatures above 40°C the rate slows down.