The changes that occur in body size, proportions, and skeletal maturity during the middle childhood include; Bones continues to strengthen and broaden, permanent teeth replace the primary teeth, normally a third of school age children suffer from malocclusions, making braces common by the end of elementary school. Additionally, the children's growth is slow and regular though large individual and ethics variations exists in the physical growth. <span />
Answer: 4.25%
Explanation:
As at Friday, May 28, 2021, the population of the United States of America is about 332,754,370. The population of the world is about 7,868,904,000.
Therefore, the percentage of the global population lives in the United States is about 4.25% that's 332,754,370/7,868,904,000 × 100%.
It has11 protons and neutrons atomic number=11 mass=22
Because if we're simultaneously moving/manipulating two different variables it can be very hard to determine why one variable is changing and why the other is changing. While this can be done with more complicated experimental designs, it usually is the case that scientists will only manipulate one variable and not two different ones.
After hundreds or even thousands of generations both alleles for sickle cell anemia are still common in those of African ancestry. This is supported by two mechanisms: heterozygote advantage and gene flow.
Heterozygote advantage
When an allele is said to be heterozygous, it is carrying one copy of a gene. For example if one carries a copy of sickle cell allele, it will stay in the population even after many generations — natural selection will not be able to remove it and it will be passed on through generations. So, having one copy of that allele is advantageous but not deleterious.
Gene flow
With humans migrating throughout the different parts of the world, sickle cell allele is passed from one person to another or in different populations. It is actually advantageous to have one copy of this allele especially if there’s malaria in the area, which the allele is resistant.
