Answer:
B. it expands and shrinks in the soil
Answer:
In eukaryotic cells you find core and proximal promoters.
Promotors are specific DNA sequences where transcription factors (proteins) and RNA polymerase binds to initiate transcription. Promotors are located upstream the coding sequence
Core promoters are where RNA polymersae binds and proximal promoters are where transcription factors bind.
Enhancer elements are DNA sequences where transcription factors (proteins) bind to increase the rate of expresion of an specific gene. Enhancers can be located either upstream, downstream or thousands of nucleotids away from the of the coding region.
Explanation:
Promoters and enhancer are key elements for controling gene regulation. Transcription begins when chromatin rearranges from a condensed state to a accesible state, this allow to transcrition factors and RNA polymerase to bind specif DNA sequences (promotors). Proteins bind to enhancers , this complex develops a DNA loop, so that the protein that is bound to the enhancer interacts with the RNA polymersase. When this interaction is made, the activity of the RNA polymerase is increased.
Answer:
Because of homologous recombination
Explanation:
- When genes are establish on different DNAs or far apart on the same chromosome, they are classified self-sufficiently and are said to be unlinked.
- When genes are very close together on the same chromosome, they are said to be linked. That means that alleles, or genetic versions, that are already together on a chromosome will be inherited as a unit more often than not.
- We can see if two genes are linked, and how closely, by using data from genetic crosses to calculate the frequency of recombination.
- Using the technique of discovery recombination happenings for numerous gene pairs, we can make link maps that show the order and relative distances of the genes on the chromosome.
- When the genes are on the same chromosome but far apart, they are classified independently due to crossing (homologous recombination). This is a procedure that happens at the start of meiosis, in which homologous DNAs randomly exchange matching fragments. Crossing be able to connection new alleles in combination on the same chromosome, causing them to enter the same gamete. When the genes are far apart, the crossing occurs with sufficient frequency for all types of gametes to occur with 25% percentage frequency.
- When the genes are very close together on the same chromosome, the crossing still occurs, but the result (in terms of the types of gametes produced) is different. Instead of being classified independently, genes tend to "stay together" during meiosis. That is, alleles of genes that are already together on a chromosome will tend to pass as a unit to gametes. In this case, the genes are linked
Answer:
C.Silicon
Explanation:
By far, the most prevalent bulk material for solar cells is crystalline silicon (c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon or water.
