Final answer:
The statement that Vitamins B9 (folate) and B12 are necessary for the synthesis of DNA precursors is true, as they play crucial roles in the formation of new cells, including erythrocytes and neural cells, and are involved in essential biochemical processes required for DNA synthesis.
Step-by-step explanation:
The statement that Vitamins B9 (folate) and B12 are necessary for the synthesis of DNA precursors is true. Vitamin B9, also known as folate, is essential for the formation of the neural tube in early pregnancy and can prevent birth defects such as spina bifida and anencephaly. Additionally, folate plays a key role in the production and maintenance of new cells by aiding in the synthesis of DNA and RNA.
Vitamin B12 has important roles in normal cell division and is essential for the maturation and development of erythrocytes. It is critical for DNA synthesis as it is required for the conversion of methylmalonyl-CoA to succinyl-CoA. Vitamin B12 is also involved in the methylation of homocysteine to methionine, which is an important step in the synthesis of DNA precursors.
Both of these vitamins cannot be synthesized by the body or most organisms and must be obtained from the diet. Vitamin B12 is primarily found in animal products such as liver, eggs, meat, and fish, making it particularly important for those on vegetarian or vegan diets to be aware of their B12 intake and consider supplementation if necessary.