What is the role of producers in the environment?
a) the producers construct objects (e. g., a bird making a nest or a beaver making a dam).
b) the use energy from the environment such as the sun as to make food via photosynthesis,
c) they are at the top of the food chain by regulating population (e. g., a wolf).
d) these species are the most valuable because they create products sold to consumers.

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Chapter 11.1 & 11.2 notes section 11.1 1. every living thing has a set of ? inherited from its parents. 2. after becoming a ? , mendel spent several years studying ? and mathematics at the university of vienna. 3. during sexual reproduction, male and female reproductive cells join, a process known as ? . 4. pea flowers are normally ? , which means that sperm cells in pollen fertilize the egg cells in the ? flowers. 5. when mendel crossed plants with ? characters for the same trait, the resulting offspring had only one of the characters. 6. a ? is a specific characteristic, such as seed color or plant height, that varies from one individual to another. 7. filius and filia are the latin words for ? and ? . 8. the offspring of crosses between parents with different traits are called ? . 9.to mendel's surprise, all of the offspring had the character of only ? of the parents. 10. mendel's first conclusion was that biological inheritance is determined by ? that are ? from one generation to the next. 11. scientist calls the chemical factors that determine traits ? . 12. mendel's second conclusion is the ? . 13. the principle of dominance states that some alleles are ? and others are ? . 14. when mendel allowed the f1 plants to reproduce by self-pollination the traits controlled by ? alleles reappeared in about ? of the f2 plants in each cross.

In an experiment examining the effects tai chi on arthritis pain, callahan (2010) selected a large sample of individuals with doctor-diagnosed arthritis. half of the participants immediately began a tai chi course and the other half (the control group) waited 8 weeks before beginning. at the end of 8 weeks, the individuals who had experienced tai chi had less arthritis pain that those who had not participated in the course.