Answer:
Due to presence of these structures in ancient as well as modern organisms.
Explanation:
Homologous and vestigial structures are the evidences that show evolutionary relationships between organisms because these structure were also present in the ancient ancestor of that organism. These homologous and vestigial structures shows the relationship between the ancient and the modern organisms. Some structure has a purpose and function in the body of ancient organisms but with the passage of time those structure are useless and have no function in the body but these structure shows connection between modern and ancient organisms.
Proteins function optimally at a specific temperature. So if you get too hot or too cold, biochemical reactions in your body start to function less well. If the situation becomes extreme enough, they can cease to function well enough to sustain life.
Warm-blooded animals have an advantage over cold-blooded ones in that their bodies automatically try to maintain the optimal termperature for things in their bodies to function. Cold-blooded animals depend on the environmental temperature to do this for them. That's why reptiles are very sluggish when they're cold, but will "wake up" when they get warm.
The cost to this benefit is that metabolically, warm-blooded animals require a lot more fuel to run their bodies. It's very energy-intensive to maintain a constant body temperature. Cold-blooded animals require far less fuel than warm-blooded ones relative to their size.
The way that proteins operate in a specific temperature is also true of the pH in your body which is also very tightly maintained.
Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells. This process is required to produce egg and sperm cells for sexual reproduction. During reproduction, when the sperm and egg unit to form single cell for sexual reproduction. During reproduction, when the sperm and egg unit to form a single cell, the number of chromosome is restored in the offspring.
Meiosis begins with a parent cell that is diploid, meaning it has two copies of each chromosome. The parent cell undergoes one round of DNA replication followed by two separate cycles of nuclear division. The process results in four daughter cells that are haploid, which means they contain half the number of chromosomes of the diploid parent cell.
The answer would be hypothalamus.
Hypothalamus is a part of the brain that located below the thalamus (hypo mean "under"). Hypothalamus can control nervous and endocrine system. It was divided into front/anterior, tuberal and back/posterior part. Thirst would be regulated by anterior and posterior part, temperature by anterior part and sexual behaviour by anterior part.