Answer:
Relaxation of the dartos muscle.
Explanation:
Testes are present in scrotum outside the pelvic cavity to maintain the temperature about 2-3 degrees Celsius below the body temperature as required for sperm production. Dartos muscle is the layer of smooth muscle located in the superficial fascia. The contraction of dartos muscle serves to make the skin of the scrotum wrinkled and tight.
During hot weather, the dartos muscle relaxes and makes the surface of scrotum less wrinkled to increase the loss of the heat from its surface. The increased heat loss from the surface of scrotum due to relaxed dartos muscles keeps the testes protected from heat.
Answer:
An arctic fox changes its fur color to blend in with its surroundings
Explanation:
This is a defense mechanism because when it blends into its surroundings it can hide from its predators and help defend itself
Answer:
The UN projects that the global population increases from a population of 7.7 billion in 2019 to 10.9 billion by the end of the century. By that time, the UN projects, fast global population growth will come to an end.
Beneath the global level, there are of course, big differences between different world regions and countries. While in some regions the world population will likely grow rapidly for the coming decades other regions will continue to see declining population numbers.
Global population growth is determined by the number of births and deaths. Improving health is increasing the size of the population as it is decreasing mortality. The countervailing trend are falling fertility rates – the trend of couples having fewer children is what brought rapid population growth to an end in many countries already, and what will bring an end to rapid population growth globally.
The global population growth rate has already slowed down considerably: It reached its peak at over 2% in the late 1960s and has been falling since.
The UN projections for the global population growth rates, which have been produced since the 1950s, have a good track record in projecting the size of the global population.
While the UN projections are most widely know there are other very carefully produced projections. The demographers of WC-IIASA model what will happen according to different scenarios and make clear that the population growth rate tomorrow depends on what we do today. Rapid progress in getting children and especially girls into schools will result in a much smaller global population.
The biggest disagreement between different projections is concerning the future of Africa. While the UN projects a 3.5-fold increase of the population of Africa, other researchers find a much smaller increase more likely.
Explanation:
here try this
The percentages of the daily values on food packages are given in terms of a person requiring 2000 calories each day
