Class 10 Science Chapter 6 MCQ

The correct path of urine is Kidney → Ureters → Urinary bladder → Urethra. The urine formed in each kidney eventually enters a long tube, the ureter, which connects the kidneys with the urinary bladder. Urine is stored in the urinary bladder until the pressure of the expanded bladder leads to the urge, to pass it out through the Urethra.

Non-living things which are not alive cannot move by themselves. For example, a stone is a non-living thing which cannot move by itself from one place to another or show any other type of movement. We will have to move it by applying force from outside.

Using the material in the form of carbon dioxide and water which is converted into carbohydrates in the presence of sunlight and chlorophyll. Carbohydrates are utilised for providing energy to the plant. The carbohydrates which are not used immediately are stored in the form of starch, which serves as the internal energy reserve to be used as and when required by the plant.

Digestion process starts from the mouth where salivary glands are present. Salivary glands produce amyloses. So, amylase is the first enzyme to mix with food. The saliva secreted by the salivary glands in mouth contains this enzyme that breaks down starch. Pepsin is a protein digesting enzyme secreted by the gastric glands present in the stomach wall. The pancreas secretes pancreatic juice in the small intestine. It contains enzymes like trypsin for digesting proteins. Cellulase is an enzyme complex which breaks down cellulose. Most animals, including humans (except ruminants) do not produce cellulase and are therefore unable to use most energy contained in plant material.

Nephrons are the filtration units of kidneys. It is the structural and functional unit of a kidney and has three functions – filtration, reabsorption and secretion. Urine from the kidney passes through a tube called ureter, that carry urine into the urinary bladder. The urethra is a canal that carries urine from bladder and expels it out of body. Neurons nerve cells and are functional units of nervous system.

The oesophagus carries food to the stomach. When the slightly digested food enters the food pipe, the walls of food pipe start contraction and expansion movements. The contraction and expansion movement of the walls of food pipe is called peristaltic movement. This peristaltic movement of food pipe pushes the slightly digested food into the stomach.

The following events occur in photosynthesis (i) Absorption of light energy by chlorophyll. (ii) Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen. (iii) Reduction of carbon dioxide to carbohydrates.

In Pisces (fishes), the heart is 2 chambered oral pumps deoxygenated blood to the gills, where oxygenation takes place by diffusion. The oxygenated blood from the gills is supplied to the body parts where oxygen is utilised and CO2 enters it making the blood deoxygenated. This deoxygenated blood returns to the heart. Thus, it has single circulation, i.e., blood passes through the heart only once during one complete cycle.

When there is a lack of oxygen in our muscle cells, another pathway for the break-down of pyruvate is taken. Here the pyruvate is converted into lactic acid which is also a three-carbon molecule. This build-up of lactic acid in our muscles during sudden activity causes cramps.

Here, all the statements are correct. Hence your answer will be option [D].