What is the name of a classification key in which there are always two choices

Explain how the level of oxygen and carbon dioxide in the blood will trigger the respiratory center

The independent variable in an experiment is OA) the same in every experiment OB) the variable scientists observe for changes O C) the variable that is changed by the scientist OD) the thing that is kept constant during the experim

According to the endosymbiotic hypothesis, why did the large cells not destroy the small aerobic cells they engulfed? A. because they were so tough B. because they provided energy C. because they were parasites not food D.

What is the pathway of air into the body? nose → nasal cavity → pharynx → trachea → larynx → bronchi → lungs nose → nasal cavity → pharynx → larynx → trachea → lungs → bronchi nose → nasal cavity → larynx → pharynx → trachea → bronchi → lungs nose →

Predict the phenotype that will be expressed by a snapdragon that is heterozygous for flower color (Rr).

Why do our classification systems change?

Potato plant, which organ is used primarily for food storage rather than food production? A) flower, B) root, C) stem, D) left

Which of the following is an example of an extended product responsibility? Select one: a. ecotourism b. soft loans for business planning to implement environmental products c. the use of recycled wood products in the manufacture of new products d.

What is an organism that lives on or in another organism and uses the other organism for nourishment to the detriment of the host organism?

If I turn my computer off at least once a week, it will run faster. What is the independent variable? What is the dependent variable? What are some controlled variables?