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.
According to the Food and Nutrition Board, of the National Academy of Sciences, 10% to 35% of kilocalories should come from protein.
There are six classes of food, but the three majors ones, that are require in large quantity are carbohydrates, proteins and fats and oils. The Food and Nutrition board gave recommendation about the quantity of these classes of food that should be taken on a daily basis. It is recommended that, 45% to 65% of kilocalories should come from carbohydrates while 20% to 35% come from fat.
Answer:
B. The tropospheric gases move becuase of convection currents.
Explanation:
The uneven heating of the regions of the troposphere by the sun ( the sun warms the air at the equator more than the air at the poles )causes convection currents, large-scale patterns of winds that move heat and moisture around the globe. In the Northern and Southern hemispheres, air rises along the equator and subpolar ( latitude about 50 to about 70 north and south ) climatic regions and sinks in the polar and subtropical regions. Air is deflected by the Earth's rotation as it moves between the poles and equator, creating belts of surface winds moving from east to west ( easterly winds ) in tropical and polar regions, the winds moving from west to east ( westerly winds ) in the middle latitudes. This global circulation is disrupted by the circular wind patterns of migrating high and low air pressure areas, plus locally abrupt changes in wind speed and direction known as turbulence.
Answer:
When the pollen tube grows into the ovule
Explanation:
Simmilar to animals, fertilization occurs when the egg (ovule) and the sperm join together to produce a new individual. In flowers, when the pollen tube grows into the ovlue is when pollen and ovule join together and fertilization occurs. A new seed is the produced, ready to produce a new individual.
