Carlos and veronica lead very similar lifestyles. they both run every day and eat healthily, but they both have smoked since they were 16. carlos was diagnosed with lung cancer when he was 48, but veronica never got cancer.

which most likely explains why carlos got cancer but veronica did not?

1 veronica leads a healthier lifestyle than carlos.
2 carlos has a gene for cancer that was triggered.
3 veronica has a gene for cancer that carlos does not.
4 carlos leads a healthier lifestyle than veronica.

(2). Carlos has a gene for cancer that was triggered.

Explanation:

Both Carlos and Veronica have smoked, but only Carlos was diagnosed with cancer at later stages. This is because of Carlos had higher risk for developing cancer.

It is defined genetic predisposition, which represents an increase susceptibility of developing a disease based on genetic makeup of a person. It might possible that Carlos has a gene for lung cancer that was triggered due to smoking as tobacco contains mutation-causing agents, and caused cancer.

For example, people having mutation in one copy of gene p53 (a tumor suppressor gene) have higher chances of developing cancer as mutation in another copy of this gene can induce cancer.

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.