I believe the polysaccharide that provides rigidity and strength in plants would be cellulose. As this is one of the essential components found in the cell wall of plant cells.
I think the correct answer is option B. A newborn child is experiencing severe heart problems and has abnormally short limbs is caused by exposure to radiation. Exposure to this causes disturbance to the early development of the baby.<span />
The answer is False.
Although, there are some evidence that suggests that species from million years ago possessed both gills and lungs. For example is the Acanthostega Gunnari, one of the oldest species discovered with four limbs. The creature is a salamander-like creature found in Greenland hundreds of million years ago. Although the specie can walk on land but the finding characterized the creature primarily as a fish.
The gene which is produced once or twice in a lifetime is the milk producing hormone after childbirth. This is because it is produced only after the birth of the child. The growth of the mammary glands takes place during pregnancy. The breast continue to increase in size after giving birth to a child. After delivery only copious milk is produced which is generally done with the help of milk hormone. During pregnancy the secretion of the milk is inhibited by the estrogen and progesterone which circulates in the blood stream which in turn inhibits the release of prolactin from the pituitary gland thus making the mammary glands unresponsive. Where as insulin is a hormone which helps the body to utilise the sugar or glucose from different sources like carbohydrates that we get while we eat food and adrenaline is secreted when we are scared or when we feel that we are in danger. Therefore, milk producing hormone is the gene that are turned once or twice in a lifetime.