Explain the flaw in Ahmed's rationale in the following scenario: Ahmed is a breeder who would like to synchronize the heat and ovulation of his herd. He keeps the herd in the same barn, at a regulated temperature, and ensures that each cow receives the proper immunizations and nutrition. After six months of this practice, Ahmed cannot understand why the herd's cycles are not synchronized.

Fill in the blank 1. digestion occurs in the small intestine through the action of enzymes. 2. urea, excess water, and other waste materials are eliminated in a water fluid called 3. can cause infections by injecting dna or rna into hosts. 4. the human immune system produces in response to a vaccine, which later can bind to and destroy a pathogen if it invades. 5. are structures that link bone to bone at a joint 6. in the heart, blood flows from the right atrium to the right ventricle, where it is pumped to the the words i can use are: lymphocytes gliding pivot gas urine absorption dermis fulcrum lungs chemical viruses capillary vertebrae esophagus tendons antibodies synapses ligaments kidneys pathogens