Does not have a distinct nucleus
bacteria has a strand of DNA/RNA called plasmid
The answer is B <span>that bony fish evolved before land plants </span>
Answer:
DNA can be described as the molecules which carries the genetic code for every individual. The DNA is made up of nucleotide bases which join the two strands of DNA. The sugar and phosphate form the backbone of the DNA.
Genes are the hereditary molecules which are made up of DNA. The alleles of a gene represent which traits will be carried by an organism.
Chromosomes are made up of genes. During reproduction, crossing over of DNA occurs and alleles of the genes assort independently due to which variations occur.
The answer is; the melanin in darkly pigmented skin protects DNA from UV radiation, and UV radiation can cause skin cancer
In Africa, due to its equatorial latitude location, receives direct sunlight at more or less 90 degrees most of the year. These highly concentrated rays increase the UV radiation exposure that can cause damage to cell DNA. Selection pressure, therefore, favored individuals with high melanin concentrations that protect against UV. Therefore population evolved towards high melanin densities in the skin.
