Answer:
because parents only give the child 1/2 of their chromosomes
Explanation:
Atmospheric Fixation. The enormous energy of lightningbreaks nitrogen molecules and enables their atoms to combine with oxygen in the air forming huge nitrogen oxides. These dissolve in rain, forming nitrates, that are carried to the earth.
Answer:
Cyanobacteria
Explanation:
Cyanobacteria were the first photosynthetic autotrophs that used water molecules as the source of electrons. Cyanobacteria were the first autotrophs that performed oxygenic photosynthesis and carried out the splitting of water.
The process of splitting water released oxygen as a gas (O2) which was released in the atmosphere of the earth as a by-product. This led to the accumulation of oxygen in the atmosphere. Some cyanobacteria can fix nitrogen and have specialized cells called heterocyst which serve as the site for nitrogen fixation.
Answer:
A testable question is one that can be answered by designing and conducting an experiment. The answers to a testable question can be observed and measured. Hypothesis- a testable explanation of an observation. A hypothesis is NOT just an educated guess about what you think will happen.