Answer:
increasing birth rate with a greater number of young organisms
True, temperature and precipitation affect the overall weather and climate of a place.
Answer: Endocrine
A chemical signal produced in the pituitary gland at the base of the brain binds to a receptor on liver cells. This signal would be classified as an endocrine signal.
Explanation:
An endocrine signal is produced by a cell that targets a distant cell through the bloodstream.
Hence, a endocrine signal (carried by hormones) produced at the base of the brain (usually an endocrine gland) travels through the bloodstream to the target cell and binds to a receptor on the liver, and then exerts its function.
Answer:
The lac repressor is not bound to the operon.
Explanation:
The lac repressor is a protein encoded by the lac I gene. In absence of lactose, the lac repressor binds to the operator sequence of the lac operon and does not allow the RNA polymerase to express the operon. However, as lactose enters the cell from the medium, the beta-galactosidase enzyme converts it into allolactose which in turn serves as an inducer of the lac operon. Binding of allolactose to lac repressor trigger conformational changes in the protein and renders it unable to bind to the operator. The RNA polymerase is allowed to express the operon.
Explanation:
Before explaining the following phenomenon, it is good to clarify one thing: the laws of thermodynamics are fulfilled and cold water usually freezes faster than hot water. However, and although it seems counterintuitive, it has been observed for centuries that this fact is not always fulfilled and under certain circumstances, hot water freezes before cold water. Aristotle was the first to record this phenomenon, but it was not published as a scientific observation until 1969 by Erasto Mpemba. Precisely due to the surname of the scientist born in British Tanganyika, this phenomenon is known as the Mpemba effect. A curious effect that has recently been having an impact due to a new viral called "boiling water challenge" and consists of throwing boiling water into the air to see how it quickly freezes and turns into snow.
