Part one: "Ultraviolet Radiation: The Sun’s radiation comes to Earth as many different wavelengths of electromagnetic energy. One form of energy is ultraviolet radiation. A person’s overexposure to the Sun’s ultraviolet radiation (UV rays) is the biggest risk factor for skin cancer. Some ultraviolet radiation is absorbed by the ozone layer, which is located in Earth’s atmosphere. This ozone layer provides a natural protection for living organisms." State one reason why all of the ultraviolet radiation coming toward Earth does not reach Earth’s surface. Part 2: Using the text above: Describe one action a person can take to avoid overexposure to UV radiation

Someone help me please

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation:

it creates acid rain

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation: