The answer is B. A chemical reaction consists of an endothermic stage (energy taken in to break chemical bonds) followed by an exothermic stage (energy released as bonds are formed). The first stage requires this energy input, which is the activation energy. When the activation energy is reached or exceeded, the reaction will occur. Therefore as soon as this threshold is REACHED, it happens
Answer:
In a population, a specific gene has two alleles, 'A' and 'a.' Individuals with
genotype 'aa' die in early childhood. Individuals with genotype 'Aa' have a
higher rate of surviving and reproducing than individuals with genotype 'AA.'
This phenomenon is called survival of the fittest, Darwins law which entails the fittest organisms survives while the ones that could not would go into extinction
Explanation:
Answer:
Endocrine disruptors are the synthetic or natural chemicals that may interfere with the functioning of the endocrine system in the human body. These chemicals mimic the naturally occurring hormones produced in the body like estrogen (a female sex hormone) and androgen (a male sex hormone) also these interfere with the production of the thyroid hormone. They bind to the receptors present in a cell and prevents the endogenous hormone from binding. The normal signaling process fails to respond properly.
Chemicals that functions as endocrine disruptors include dioxine, polychlorinated biphenyls (PCBs), pesticides and DDT.
