Basically it is more complex then just one locus gene interaction, but basically if both parents have brown hair they can have a child with blonde hair because both parents could be heterozygous for brown and pass on the recessive allele for blonde hair. in simple genetic analysis this would happen to 25% of the children.
.Edu is probably the most reliable source because this means the site has valid information.
The cause of acquiring cancer does not only rely on genetics. Cancer can be caused by a lot of factors and the most common factor considered why it statistically appear to run in families is the family's lifestyle. Most forms of cancer are lifestyle-related, and can be prevented. For example, Colon cancer. Usually a person is at risk to acquire colon cancer when he/she consumes too much processed meats and meats that are cooked at a very high temperature, alcohol use and overeating. Usually this kind of eating lifestyle is shared by the family.
Answer:
D. The threat of predators to eat eggs
Explanation:
The internal gestation followed by live birth was an adaptation developed by the mammals on land, and by some fish in the water, like the sharks. The mammals have been the most marking ones in this adaptation though. They too were producing eggs initially, but because they were living in an environment where there were numerous animals that preyed upon them, as well as their eggs, they had to be innovative. They developed internal gestation, where the embryo was developing inside the body of the female, and then it was born alive. This was providing extra safety, as the embryo was always with the mother, instead of being left alone and not guarded, thus an easy meal for the predators. The two types of internal gestation that the mammals developed are the placental and marsupial types, with the placental turning out to be more successful over time.
An organisms role is important for the community because they help us to have food & to keep us alive
