Answer: True
Explanation: A mutation can help an organism survive in a particular environment. A mutation is a change in the nucleotide sequence of an organism. A mutation can be of three types - beneficial, harmful or neutral. A mutation is considered to be beneficial when it produces a variation that helps the organism to better adapt to its environment.
The main big one would be disease and infections. Trench fever, trench foot and trench mouth were common diseases people got when involved in trench warfare. Trench foot happens when the feet are exposed for long periods of time to cold water and mud. Trench fever is caused when body ice transfers from one place to another. Overcrowding conditions make this prone to happen. It causes headaches, sore muscles, skin lesions on the chest and backs as well as fever.
I hope this helps :)
Answer with Explanation:
<em>Genetics' influence on the happiness</em> of a person has long been studied. Some people say that the genes of a person affects the person's mood. For example, "5-HTTLPR" is a gene that is regarded to be connected to depression. This is why it is called<u> "the depression gene."</u> It is also associated with sleep disorders like "insomnia." When someone has trouble sleeping, it disrupts his way of life thereby affecting his happiness.
On the contrary, the genes exhibit themselves according to external environments. This is also one reason why a person's happiness may also be determined by his<em> success in life, material possession, relationships with people and so on.</em> So, a person's situation in life partly influences his happiness.
