Answer:
Although direct calorimetry is considered to be the most precise technique for the measurement of metabolic rate, construction of such a chamber that is large enough for doing exercise physiology research (or any research for that matter) is extremely expensive and not at all mobile.
Explanation:
Direct calorimetry measures the heat production of an individual, in calories, when placed in an insulated chamber where the heat is transferred to surrounding water. This is a very accurate method of measuring energy expenditure.
Answer:
The answers are:
1. initial composition of microbial community (controlled variable)
2. age of the mice (controlled variable)
3. change in body fat (dependent variable)
4. diet (independent variable)
5. weight gain (dependent variable)
6. final composition of the microbial community (controlled variable)
Explanation:
Before I go ahead to explain each of the choices of classification, let us define each of the different types of variable.
1. Independent variable: this is a variable that is under the control of the experimenter. It is made up of the factors that are being tested. In our example, the independent variables is; diet. The aim of the experiment is to study the effect of the type of diet on the mice. The diet can also be varied and assigned at will by the experiment.
2. Dependent variable: a dependent variable is one whose outcome is reliant on the effect of the changes in the independent variable. It is the factor to be measured. In our example, the factors that obey these definitions are; change in body fat and weight gain. these two factors depend on the types of diet taken by the mice, hence they are the factors to be measured.
3. Controlled variable: these are variables that are kept constant throughout the experiment to rule out biases, because they produce the same effect on the dependent variable as the independent variable and must be keep constant or uniform in the test groups. in our example, the factors that are controlled include; initial and final compositions of the microbial communities and the age of the mice, because the microbial composition if not uniform among the groups can cause biases in how the diets are processed, and the age of the mice also must be uniform to avoid age-related differences in the processing of the diets
Sunlight is the main change! sun light cannot penetrate into the deep layers of the ocean and availability of oxygen is also low there. this causes the considerable amount of organisms to live in the upper layers of the ocean and we can only observe decomposing organisms in the deeper layers!
Answer:
During the Devonian period which occurs 375 million years ago, gills are present in the fossil of tetrapods.
Explanation:
Gills present in tetrapods which able the marine animals to breathe inside water but with the passage of time the sac which is present around the gills convert into lungs and these tetrapods are able to live on the land. Examples of tetrapods are frog, lion, birds and salamander etc.
The correct answer is that "xylem transports water, stomata take in carbon dioxide, and chlorophyll absorbs sunlight." The xylem is a vascular structure in plants that transport water, the phloem is another vascular structure in plants that transport nutrients. The stomata (singular; stoma) is the one responsible for the plants' gas exchange (takes in carbon dioxide, releases oxygen). The chlorophyll is what makes the green pigment of the leaves and mostly because of the presence of chloroplasts, the organelle in plant cells responsible for photosynthesis.
