Answer: a. Increasing the surface area for diffusion
Explanation:
When the air is inhaled through the nostrils, the air containing the oxygen the air diffuses inside the alveoli. The alveoli are the tiny sacs where air enters and exchange of gases takes place. From the alveoli the oxygen enters into the blood stream. The oxygen is utilized by the cells for respiration. The increase in network and number of the alveoli will increase the surface area for the diffusion of oxygen and hence, will speed up the respiration process.
Answer: Carbon 12 and Carbon 13
In plant, the ratio of carbon 12 and carbon 13 isotopes is different depending upon the plant photosynthesis. The distribution of these isotopes in plant tissue can indicate the path way of carbon metabolism that is either C3 fixation or C4 fixation. This help scientist to know if the plant consumed by organism is C3 plant or C4 plant by measuring the isotopic signature of their collagen and other tissues.
This can help scientist know which plant is consumed by animals.
The answer is B. Speed up chemical reactions. Hope this helps.
Answer:
D. Weight varies with location, but mass does not vary
Explanation:
Weight can be defined as the force acting on a body or an object as a result of gravity.
Mathematically, the weight of an object is given by the formula;
Where;
- m is the mass of the object.
- g is the acceleration due to gravity.
Mass can be defined as a measure of the amount of matter an object or a body comprises of. The standard unit of measurement of the mass of an object or a body is kilograms.
Irrespective of the location of an object or a body at a given moment in time, the mass (amount of matter that they're made up of) is constant. This ultimately implies that, whether you're in the moon, space, earth or any other place, your mass remains the same (constant).
<em>Hence, the statement that correctly compares mass and weight is that, weight varies with location, but mass does not vary. This is simply because acceleration due to gravity changes with location i.e its value varies with the planets.</em>