A layer of ice on the surface keeps the water temperature warmer than the air temperature.
Answer:
The correct answer is-
Hypothesis: Antibiotics cause weight gain in cows.
Independent Variable: Antibiotic pill
Dependent Variable: Weight of cow
Control Group: a group of cows gets a placebo pill
Experimental Group: a group of cows gets an antibiotic pill
Explanation:
The Independent variable is the variable that causes the response from the dependent variable or affects the dependent variable in this study the antibiotic pill affects the weight of cows so The independent variable is an antibiotic pill and the dependent variable is the weight of cows.
The control group is the group of subjects that did not get the treatment in a scientific study in the case of this study group of cows that receives the placebo pill is the control group and the experiment group is subjects that receive the treatment which is a group with the antibiotic pill.
Concentration gradient across the membrane. Proteins in the membrane allow specific molecules through, passively.
More than one third of North American bird species can be found in wetlands. Wetlands may contains fresh or salt water or both. Biodiversity and nutrient levels are high; many plants and organisms filter out waste materials. Birds like geese, ducks, herons, warbies, and egrets, to name a few, use wetlands for nesting and feeding.