Answer:
In order to find out whether the oxygen in CO2 comes from the sugar or from oxygen gas, we will perform radioactive labeling one by one on oxygen of sugar and oxygen of gas.
After this, we will observe the results and find that labelling of oxygen done in case of sugar produces radio labelled CO2 whereas labelling done in atoms of oxygen gas did not give a radio labelled CO2.
From this, it is concluded that in the process of cellular respiration ( oxidation of sugar to give energy in the form of ATP while producing water and CO2 as waste products), CO2 comes from the sugar molecule and not from oxygen gas.
Answer:
Explanation:
The conversion of nitrogen gas (N2) into nitrates and nitrites through atmospheric, industrial and biological processes is called nitrogen fixation. Atmospheric nitrogen must be processed, or "fixed", into a usable form to be taken up by plants. Between 5 and 10 billion kg per year are fixed by lightning strikes, but most fixation is done by free-living or symbiotic bacteria known as diazotrophs. These bacteria have the nitrogenase enzyme that combines gaseous nitrogen with hydrogen to produce ammonia, which is converted by the bacteria into other organic compounds. Most biological nitrogen fixation occurs by the activity of Mo-nitrogenase, found in a wide variety of bacteria and some Archaea. Mo-nitrogenase is a complex two-component enzyme that has multiple metal-containing prosthetic groups.[22] An example of free-living bacteria is Azotobacter. Symbiotic nitrogen-fixing bacteria such as Rhizobium usually live in the root nodules of legumes (such as peas, alfalfa, and locust trees). Here they form a mutualistic relationship with the plant, producing ammonia in exchange for carbohydrates. Because of this relationship, legumes will often increase the nitrogen content of nitrogen-poor soils. A few non-legumes can also form such symbioses.
I think it's pain receptors.
In mitosis which produces body cells, each daughter body cell would have 46 chromosomes.
But during meiosis which produces sex cells, each daughter sex cell would have 23 chromosomes.
Answer:
New cells are spontaneously created from existing cells
Explanation:
In the 1830's, three scientists namely: Matthias Schleiden (a botanist), Theodor Schwann (a zoologist) and Rudolf Virchow proposed the Unified cell theory. In this theory, three parts were universally accepted and they are as follows:
1) Cells are the fundamental and basic unit of all life and structure.
2) All living organisms are made up of one or more of these cells.
3) New cells arise from already pre-existing cells.
These three parts are the widely accepted parts of the cell theory. Although, it was once believed that new cells arose from inorganic matter. This theory, called spontaneous generation or abiogenesis was later disapproved.
Therefore, the statement that, "new cells are spontaneously created from existing cells" is not a part of the CELL THEORY.