B An ecosystem because it is i dont know how to explain but i think is that one
A. they arose out of Africa less than 200,00 years ago
Explanation:
zoology is the study of animals or it's the phenomenon that talks about animal and beasts that lives in the zoo
The sun feeds the plants through the process of photosynthesis. the animals gain energy and grow by eating those plants. other animals eat those animals and gain energy and grow. the cycle is never ending and all begins with the sun. without it, the plants and animals wouldnt get food and die off.
The correct answer is: b. the removal of introns and alternative splicing of exons
Post-transcriptional regulation includes processes of regulation between transcription and translation such as RNA splicing, capping, addition of poly-A tail, RNA editing.
RNA splicing represents the process of RNA processing in which newly synthesized pre-mRNA transcript is converted into a mature mRNA. This process occurs only in eukaryotic organism and includes the removal of introns and joining together the exons. RNA splicing might occur during or immediately after transcription and it is performed by spliceosome (complex of small nuclear ribonucleo proteins).
Alternative splicing is a regulated process in which a single gene can code for multiple proteins because particular exons of a gene may be included within or excluded from the final mRNA.