Beriberi is a nervous system ailment caused by a thiamine (vitamin B₁) deficiency in the diet. Thiamine is involved in the breakdown of molecules such as glucose and is also found on the membranes of neurons. Symptoms of beriberi include severe lethargy and fatigue, together with complications affecting the cardiovascular, nervous, muscular, and gastrointestinal systems.

Correct Option: C

Beriberi is a nervous system ailment caused by a thiamine (vitamin B₁) deficiency in the diet. Thiamine is involved in the breakdown of molecules such as glucose and is also found on the membranes of neurons. Symptoms of beriberi include severe lethargy and fatigue, together with complications affecting the cardiovascular, nervous, muscular, and gastrointestinal systems.

Taste buds probably play the most important part in helping us to enjoy the many flavors of food. Our taste buds can recognize four basic kinds of tastes: sweet, salty, sour, and bitter. The salty/sweet taste buds are located near the front of our tongue; the sour taste buds line the sides of our tongue; and the bitter taste buds are found at the very back of our tongue.

Correct Option: C

Taste buds probably play the most important part in helping us to enjoy the many flavors of food. Our taste buds can recognize four basic kinds of tastes: sweet, salty, sour, and bitter. The salty/sweet taste buds are located near the front of our tongue; the sour taste buds line the sides of our tongue; and the bitter taste buds are found at the very back of our tongue.

Chlorophyll is the molecule that absorbs sunlight and uses its energy to synthesise carbohydrates from CO₂ and water. This process is known as photosynthesis and is the basis for sustaining the life processes of all plants. Since animals and humans obtain their food supply by eating plants, photosynthesis can be said to be the source of our life also. Chlorophyll is the molecule that traps this ‘most elusive of all powers’ - and is called a photoreceptor. It is found in the chloroplasts of green plants, and is what makes green plants, green. The basic structure of a chlorophyll molecule is a porphyrin ring, coordinated to a central atom. This is very similar in structure to the heme group found in hemoglobin, except that in heme the central atom is iron, whereas in chlorophyll it is magnesium.

Correct Option: B

Chlorophyll is the molecule that absorbs sunlight and uses its energy to synthesise carbohydrates from CO₂ and water. This process is known as photosynthesis and is the basis for sustaining the life processes of all plants. Since animals and humans obtain their food supply by eating plants, photosynthesis can be said to be the source of our life also. Chlorophyll is the molecule that traps this ‘most elusive of all powers’ - and is called a photoreceptor. It is found in the chloroplasts of green plants, and is what makes green plants, green. The basic structure of a chlorophyll molecule is a porphyrin ring, coordinated to a central atom. This is very similar in structure to the heme group found in hemoglobin, except that in heme the central atom is iron, whereas in chlorophyll it is magnesium.

Maximum harm to a tree is caused by loss of leaves. This means that the tree will loose its ability to perform photosynthesis or food manufacture. Leaves are a plant’s main photosynthetic organs. Leaf structure is closely associated with its photosynthetic function. Leaves must permit carbon dioxide access to the photosynthetic cells but impede water from diffusing out. The oxygen that is a waste product of photosynthesis must be allowed to escape from the leaf.

Correct Option: B

Maximum harm to a tree is caused by loss of leaves. This means that the tree will loose its ability to perform photosynthesis or food manufacture. Leaves are a plant’s main photosynthetic organs. Leaf structure is closely associated with its photosynthetic function. Leaves must permit carbon dioxide access to the photosynthetic cells but impede water from diffusing out. The oxygen that is a waste product of photosynthesis must be allowed to escape from the leaf.

Carbon dioxide exists in Earth’s atmosphere in this state, as a trace gas at a concentration of 0.039 per cent by volume. The air we breathe in contains about 0.04% carbon dioxide. The air we breathe out contains about 4% carbon dioxide. In other words, exhaled air contains about 100 times the concentration of carbon dioxide that inhaled air does.

Correct Option: A

Carbon dioxide exists in Earth’s atmosphere in this state, as a trace gas at a concentration of 0.039 per cent by volume. The air we breathe in contains about 0.04% carbon dioxide. The air we breathe out contains about 4% carbon dioxide. In other words, exhaled air contains about 100 times the concentration of carbon dioxide that inhaled air does.