Answer:
Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.
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
I think it’s thick
Explanation
I think its because we don't know how to harness it, with out making things explode.
The correct answer is Option B: 3%.
In 2016, Sub-Saharan Africa, doubling time is 23.3 years, thus Growth rate is 3%.
<h3>What is doubling time?</h3>
- The doubling time is the time taken by a population to double in its size.
- This concept is applied to population growth, inflation, resource extraction, consumption of goods, the volume of malignant tumors, and many other things that tend to grow over time.
- There is an important relationship between the percent growth rate and its doubling time known as “the rule of 70”: to estimate the doubling time for a steadily growing quantity, simply divide the number 70 by the percentage growth rate.
- Therefore, Growth rate is 70 divided by doubling time (70/ doubling time).
- Here, Doubling time= 23.3 years.
- Growth rate= 70/23.3= 3%
Learn more about population growth rate here:
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