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Learning Objectives. In this section, you will explore the following questions: How was the present-day theory of evolution developed? What is adaptation, and how does adaptation relate to natural selection?
18 Δεκ 2016 · This section of the AP Biology curriculum focuses on the process of transcription and the RNA processing mechanisms that stabilize a pre-mRNA molecule, remove the introns, and ready the molecule for export from the nucleus and translation into a protein molecule.
The RNA world is a hypothetical stage in the evolution of life where RNA plays both roles, without the support of DNA (for information storage) or protein (for enzymes, structure-building, and just about everything else).
Definition. Eukaryotic cells are believed to have evolved from early prokaryotes that were engulfed by phagocytosis. Evidence. Mitochondrion and Chloroplast have double membranes, can reproduce in a fission-like process, have their own DNA which is similar to prokar‐yotic DNA, and has ribosomes similar to prokaryotes.
22 ώρες πριν · What is DNA Transcription (RNA Synthesis)? DNA transcription is a crucial biological process that involves the synthesis of RNA molecules from a DNA template. It plays a fundamental role in gene expression and protein synthesis within cells. The main focus of DNA transcription is the production of messenger RNA (), which carries the genetic information from DNA to the cellular machinery ...
In prokaryotes, gene expression is regulated primarily at the level of transcription, when DNA is copied into RNA. However, eukaryotes have evolved regulatory mechanisms in gene expression at multiple levels.
The RNA world. Biologists used to view RNA as a lowly messenger — the molecule that carries information from DNA to the protein-building centers of the cell. But discoveries since the early 1980s have shown that RNA can do much more.
