Please answer the following multiple-choice questions.

Here are the answers to the multiple-choice questions: 71. Which are the four most abundant elements in living cells? The four most abundant elements in living cells are carbon, oxygen, hydrogen, and nitrogen* (CHON), making up the bulk of organic molecules. The correct answer is B*. B 72. Which one is not correct for a productive theory? A productive scientific theory should be predictive, have explanatory power, and encourage* the suggestion of different hypotheses for further testing and refinement, not discourage them. The correct answer is C*. C 73. Conclusion of Mendel's work latter became a ________? Mendel's conclusions about inheritance, such as the Law of Segregation and the Law of Independent Assortment, are fundamental principles that describe natural phenomena and are widely accepted, thus they are considered scientific laws*. The correct answer is C*. C 74. Starch is converted into maltose by? The enzyme responsible for breaking down starch (a polysaccharide) into smaller disaccharides like maltose is amylase*. The correct answer is D*. D 75. Breeders have developed new and better varieties of food items by using which technique? Genetic engineering* allows breeders to directly modify the genetic material of organisms to introduce desirable traits, leading to new and improved varieties of food items. The correct answer is C*. C 76. Co-enzyme is often formed from? Many coenzymes are derived from vitamins* (e.g., NAD+ from niacin, FAD from riboflavin), which are essential organic molecules that assist enzymes in catalyzing reactions. The correct answer is D*. D 77. Messenger RNA is formed in ________? In eukaryotic cells, the process of transcription, where messenger RNA (mRNA) is synthesized from a DNA template, primarily occurs in the nucleus*. The correct answer is A*. A 78. Astronauts may use which technique to grow fruits and vegetables? Hydroponic culture technique* involves growing plants in nutrient-rich water solutions without soil, which is a suitable method for cultivating crops in controlled environments like space stations. The correct answer is D*. D