The fourth week after conception, growth is rapid. the neural tube along a baby's back is closing and the baby's heart is pumping blood. if this neural tube does not close properly, a condition called may result. a) fragile x b) spina bifida c) cleft palate d) down's syndrome

THe correct answer is B. Spina bifida.

Explanation

Neural tube or NTD defects are birth defects of the brain and spinal cord. These defects change the shape or function of one or more parts of the body. Also, they can cause problems in general health, and the development or functioning of the body. These defects occur in about 3,000 pregnancies per year in the United States. One of the most common NTDs is spina bifida in which the tiny bones of the spine do not close completely, and a part of the spinal cord sold by the spine. Children with spina bifida lose mobility of the legs and problems with bladder and bowel control that make it difficult for them to go to the bathroom to meet their physiological needs. So, the correct answer is B. Spina bifida.

answer; polycythemia is the correct answer;

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.