A nervous system because worms don't have nerves
Answer:
Explanation:
Transcription takes place in nucleus in the presence of the enzyme RNA polymerase.
During transcription, the code present in DNA gets transcribed into the code in mRNA. (messenger RNA)
RNA even though is a single stranded shows base pairing.
The pre-mRNA gets created from the DNA.
DNA has two strands, one of these strands acts as coding and another non coding strand.
The DNA shows base pairing with AGTC. [A-Adenine, G- Guanine, T-Thymine and C- Cytosine]
Whereas mRNA base pairing with AGUC. [ U- Uracil ]
Here in mRNA, instead of thymine, uracil gets paired.
According to base pairing of coding strand/sense strand of DNA, complementary bases pairs in 5'---->3' direction in mRNA.
The mRNA created looks exactly like the non-coding strand/sense strand of DNA except instead of thymine, uracil gets replaced.
The pre-RNA undergoes splicing, capping and tailing to form mature mRNA.
In the diagram we see a cell plant, with a few structures numbered:
0. Vacuole
,
1. Chloroplast
,
2. Nucleus
,
3. Cell wall
The answer options correspond with the functions of these structures:
0. Vacuole- Has secretory, excretory, and storage roles (B)
,
1. Chloroplast - It makes the photosynthesis (D)
,
2. Nucleus - Serves as the control center of the cell and contains the genetic information (A)
,
3. Cell wall ,- ,Provides structural support to the cell (C)
Desertification of non desert land can occur due to several reason like,overgrazing, deforestation, tilling of land, drastic climate change and drought that ultimately leads to excessive soil erosion or soil death .
Explanation:
- Desertification is the phenomena in which a productive land becomes completely unproductive, resulting in the loss of any vegetation cover over it.
- Desertification results in degradation of the soil to such an extent that the entire biotic community thriving on it is destroyed.
- Overgrazing, deforestation, tilling of land are major activities that ultimately leads to the washing away of the top soil and leaves the land deserted.
- Some natural causes include climate shifts and drought.
