Cytotoxic T cells use two basic mechanisms to destroy target cells: 1. Cytotoxic T cells release perforins which create pores on the target cells and granzymes which stimulate the apostosis of the target cells by exocytosis. 2. Cytotoxic T cells bind specific membrane receptors on the target cells and stimulate apostosis process which eliminate the target cells.
If the mass of an object increases, then its kinetic energy will increase proportionally because mass and kinetic energy have a linear relationship when graphed.
Answer:
Prokaryotes have RHO dependent and RHO independent transcription termination; Eukaryotes have the poly A signal and downstream termination sequence transcription termination.
Explanation:
Transcription is the process by which mRNA is synthesized from DNA by the enzyme RNA polymerase. The process of transcription is keep going until some termination signal/mechanism stops it. There are various differences of transcription in prokaryotes and eukaryotes like types of RNA polymerases, nitrogenous bases utilized and the mechanism of transcription termination.
Prokaryotic termination may be dependent on RHO proteins or not.
- In RHO dependent pathway the RHO factor (protein) slide towards the RNA polymerase along the DNA and dissociate it from DNA.
- In RHO independent pathway a stem loop is formed by mRNA from a sequence which pasues the polymerase temporarily and consequently causes dissociation of RNA polymerase with help of poly-uracil sequence.
Eukaryotic termination may occur through poly A signal and downstream termination sequence;
- Poly A tail is added mRNA for its protection. It prevent the mRNA degradation.
- The polymerases pauses on the termination signal and ultimately dissociates from DNA.
Answer: It makes the soil frozen and hard
Explanation: the permafrost frezzes the soil and doesnt allow any plant life to grow
Answer:
2. evidence of glacial deposits
4. evidence from fossils
Explanation:
1. that was found later by someone else which proved the theory more
3. it wasn't yet proven that continents drifted, so that couldn't be the case
