Answer:
List the features of gas exchange surfaces in animals.
1)They are moist to prevent the cells from drying and to allow gases to dissolve;
2)They have a large surface area , so that a lot of gas can diffuse across at the same time;
3)They have a high concentration gradient - maintained by the movement of air & blood.
The right answer is vein (it contains blood and has valves).
The infra-cardiac veins of small and medium caliber possess this system of fight against gravity. The valves consist of a dense connective tissue, surmounted by endothelial cells, corresponding to a fold of the intima. They allow blood circulation in the sense organ / heart but prevent venous reflux.
Explanation:
Plasma
White blood cells
Red blood cells
from top to base of test tube
Answer:
Option (B).
Explanation:
Mixture may be defined as the solution obtained by mixing of two or more substances together. Two different types of mixture are homogeneous mixture and heterogeneous mixture.
Homogeneous mixture may be defined as the mixture that has uniform composition throughout the mixture and cannot be separated easily by physical shaking process. Heterogeneous mixture are the mixtures that has different composition throughout the mixture and can be separated by simple shaking.
Thus, the correct answer is option (B).
The x-axis shows the relative
amount of DNA per cell thought not directly. This can be seen through a
histogram a specific type of a graph. Looking at the bars of the histogram you
can follow peaks and dips which correspond to something like fluorescence which
indirectly shows the relative amount of DNA in cell.
