IGCSE Biology Paper-4: Specimen Questions with Answers 120 - 121 of 279

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Passage

Carbon dioxide is important greenhouse gases. The effect of human activities in increasing the concentration of greenhouse gases, such as carbon dioxide and methane, is known as the enhanced greenhouse effect.

Question 120 (2 of 2 Based on Passage)

Describe in Detail

Essay▾

Figure shows the concentrations of carbon dioxide in the atmosphere over past years. Describe the trend in the concentrations of carbon dioxide over the past years.

Image Shows Global Carbon Dioxide Emission in 1751 - 2006

Explanation

Above graph shows how atmospheric carbon di oxide levels have dramatically increased in recent years.

Question 121

Edit

Write in Short

Short Answer▾

The structure labelled A transports enzymes to the cell membrane for release into the pancreatic duct. These structures contain molecules of amylase, trypsin, and lipase.

Complete the sentences with the most appropriate words.

Enzymes are made of protein and act as … because they increase the rate of chemical reactions, but are not changed in those reactions. Amylase speeds up the digestion of … to … Trypsin continues the chemical digestion of protein begun by the enzyme … in the stomach.

The optimum pH for pancreatic enzymes is greater than pH 7. Bile is produced by the … and enters the small intestine, where it … stomach acid to provide the appropriate pH. Bile also breaks down fat by … to increase the surface area for the action of lipase.

Explanation

Enzymes are made of protein and act as … BIOCATALYST … because they increase the rate of chemical reactions, but are not changed in those reactions. Amylase speeds up the digestion of … STARCH … to … MALTOSE/GLUCOSE … Trypsin continues the chemical digestion of protein begun by the enzyme … PEPSIN … in the stomach.

The optimum pH for pancreatic enzymes is greater than pH 7. Bile is produced by the … LIVER … and enters the small intestine, where it … NEUTRALIZES … stomach acid to provide the appropriate pH. Bile also breaks down fat by … EMULSIFICATION … to increase the surface area for the action of lipase.

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