Soil pH can affect plant growth in several ways. Bacteria that change and release nitrogen from organic matter and some fertilizers operate best in the pH range of 5.5 to 7.0 making this the optimum pH range. Plant nutrients leach from the soil much faster at pH values below 5.5 than from soils within the 5.5 to 7.0 range. In some mineral soils aluminum can be dissolved at pH levels below 5.0 becoming toxic to plant growth. Soil pH may also affect the availability of plant nutrients. Nutrients are most available to plants in the optimum 5.5 to 7.0 range. PH can also affect the structure of the soil, especially in clay soils. In the optimum range clay soils are granular and easy to work with. However, if the soil is either extremely acid or alkaline clay, soils tend to become sticky and hard to cultivate.
A pH soil test will tell you whether your soil is within the optimum range or whether it will need to be treated to adjust the pH level. Although the optimum range is 5.5 to 7.0 some plants will grow in a more acid soil and some at a more alkaline level.
PH is not an indication of fertility, but it does affect the availability of fertilizer nutrients. The soil may contain adequate nutrients yet plant health may be limited by an unfavorable pH level. On the other hand, builder’s sand, which is devoid of nutrients, may have optimum pH for plant growth.
The answer is a tumor.
Tumors are characterized by cells that have a mutation in their DNA that causes them to reproduce unregulated hence proliferate and do not form true tissues. Inhibitors, called tumor suppressors, act like a ‘brake’ in the cell cycle. Cyclins, on the other hand, are the ‘gas pedal’ for the cycle. The right balance ensures that cell cycle is well regulated. When the DNA is a cell is damaged, the tumor suppressors are rectruited to stop any further progress of the cell cycle and the cell undergoes apoptosis.
***the molecular tools are:
Restriction enzymes
Restriction genes allow the synthesis of DNA-cleaving endonucleases at very specific sites to digest parasite DNA
-RNAse
* RNA A: specifically cleaves single-stranded RNAs, and releases residues of pyrimidine 3'-phosphates
* H RNA: cleaves DNA / RNA hybridization -digests RNA in an RNA-DNA complex. It is used to remove RNA after making a first strand of cDNA using reverse transcriptase.
-Alclaline phosphatase:
Alkaline phosphatases are active at alkaline pH. They make it possible to remove the phosphate group situated at 5 'of a DNA chain. They are extracted from bacteria or animal origin (intestines). They are used to prepare recombinant DNA.
-Kinase:
Kinases make it possible to fix a phosphate group in the presence of ATP.
-the enzymes copying the nucleic acids:
* DNA Polymerase (Taq, and the Klenow fragment) for example)
* inverted transcriptase.
* RNA polymerase
-Ligase
***Use of these techniques.
The biologist has a number of tools and methods for studying gene mutation. The analysis of the gene will make it possible to diagnose certain pathologies. Then, once the pathology is known, the doctor can establish an adequate treatment for the patient in order to treat it.
The answer is c because u have look at the picture very clearly.
<span>The answer is enzymes. Enzymes are biological catalysts and increase the speed of change from substrate to product. The name of enzymes is usually derived from the substrate they break down. For example, lactase breaks down sugar lactose. The name of enzymes contains suffix -ase, for instance, carbonic anhydrase, lactase, lipase, amylase, etc...</span>
