The fertility rate of 2.1 with which populations are expected to eventually stabilize is known as the long-term replacement rate. In other words, if a nation maintains a fertility rate of 2.1 over a long period of time the population of that nation will eventually stabilize and it will neither grow nor shrink. Immigration allows the people to grow faster than the fertility rate would suggest. Also because of past growth, the population is younger than it would otherwise be. This means that there are more potential mothers and fathers. Only after its residents age can the population of a country stabilize.
Answer:
lizards, frogs and salamanders
Explanation:
Assuming that you're referring to forest ecosystem, the two ecological benefits of this ecosystem are :
- it provides habitats for many organisms
- It provide Oxygen supply for the world
Answer:
A negative charge exists because of the electronegativity of oxygen. A polar water molecule is made up of hydrogen and oxygen. Due to its atomic structure, there is an unequal distribution of charges and thus oxygen gets a more negative charge while hydrogen gets a positive charge.
Explanation:
1- Preparing the cDNA:
a- Using two different tissue samples (such as control and cancer cells), isolate mRNA.
b- For each sample, prepare complementry DNA (cDNA) from the isolated mRNA. Then fluorescent label cDNA of each sample with a different color and then mixed.
2- preparing the microarray:
a- Bind DNA fragments of different genes to microarray wells.
b- Attach ssDNA (single-stranded DNA) to microarray wells.
3- Combine the probe and the microarray samples:
Add labeled cDNA to the microarray wells.