How does protein evolution occur in living organisms?4 answersProtein evolution in living organisms primarily occurs through gene duplications, sequence divergence, and domain combinations, leading to the formation of new proteins with diverse functions and structures. Evolutionary relationships of proteins are traced through the divergence of protein domains, which can be duplicated, diverged, and combined to form new proteins. The process of protein evolution is complex and varies across different taxa, with variations in evolutionary rates among proteins reflecting differences in clades and protein structures. Proteins evolve within a structural landscape, with older proteins having more elaborate structures, while newer proteins tend to be shorter and less complex, forming a network of folds that connect different portions of the protein space. Evolution of complex protein features can occur rapidly with just a few mutations, as proteins are poised at the genetic edge of acquiring new functions and structures.
What was evolution from prokaryotic cells to eukaryotic cells incorporated into engineered living materials?5 answersThe evolution from prokaryotic cells to eukaryotic cells has been integrated into engineered living materials to create advanced biomaterials with unique properties. By utilizing genetically engineered organisms like Saccharomyces cerevisiae yeast and Komagataeibacter rhaeticus bacteria, living materials have been developed that exhibit self-assembly, self-repair, and responsiveness to environmental cues. These engineered living materials incorporate living cells within polymeric matrices, allowing for the creation of bioactive materials capable of complex responses and controlled functionalities. The symbiotic culture of bacteria and yeast enables the fabrication of living materials that can sense and respond to chemical and optical stimuli, opening up possibilities for applications in biosensing, biocatalysis, wound healing, and drug delivery. This innovative approach merges biological evolution with material engineering to produce sustainable and functional living materials.
How did eukaryotic genomes evolve?4 answersEukaryotic genomes evolved through a combination of symbiotic interactions, lateral gene transfer, and genome rearrangements. The origin of eukaryotes involves a symbiosis between Alphaproteobacteria and archaea, as supported by recent studies. The eukaryotic genome is a mosaic of genes from eubacteria, archaea, and unique eukaryotic genes, which may have been acquired through lateral gene transfer over time. The evolution of genomes is not a slow process but can involve various transformations, including the impact of transposable elements on genomes. The plant cell's integrated genome, consisting of nucleus/cytosol, plastids, and mitochondria, originated from endosymbiotic events and underwent complex restructuring and intermixing of genetic potentials, as well as lateral gene transfer. The eukaryotic nuclear genome likely descends from a specific archaea group, while the mitochondrial genome descends from alpha-proteobacteria.
What are some examples of gene evolution?5 answersGene evolution can be observed in various organisms. For example, in yeast, the expression of duplicated genes has been found to evolve rapidly, with closely related genes not being more likely to share common expression patterns than more distantly related genes. In vertebrates, gene duplication and deletion events have played a significant role in driving adaptation and speciation, particularly in the evolution of opsin genes that affect spectral sensitivity and visual displays. Additionally, a genome-wide analysis comparing brain-specific genes in humans and chimpanzees suggests that the unique features of the human brain did not arise from a large number of adaptive amino acid changes in many proteins. These examples highlight the diverse ways in which gene evolution can occur, influencing various aspects of organismal biology.
What are the differences between eukaryotic and prokaryotic ribosomes?5 answersEukaryotic and prokaryotic ribosomes have several differences. Eukaryotic ribosomes are more complex and larger in size compared to prokaryotic ribosomes. Eukaryotic ribosomes consist of four ribosomal RNAs (rRNAs) and numerous ribosomal proteins, while prokaryotic ribosomes have three rRNAs and fewer ribosomal proteins. The structures of eukaryotic ribosomes are more intricate, with species-specific variations in protein and rRNA extensions. Additionally, eukaryotic ribosomes have unique mechanistic features in translation initiation, elongation, and termination, especially in the identification and recognition of start and stop codons on messenger RNAs. The process of eukaryotic ribosome assembly is also more complex, involving three cellular compartments and the concerted action of three RNA polymerases, splicing and nucleocytoplasmic transport machinery, and over 200 transiently interacting factors. In contrast, prokaryotic ribosome assembly is simpler and occurs entirely in the cytoplasm.
What are some examples of coevolution in some species?5 answersCoevolution is the joint evolution of two or more species or genomes due to interactions between them. Examples of coevolution include interactions such as interspecific competition, mutualism, interactions between consumers and victims, and mimicry. In the case of human hands and feet, the proportions of the digits have coevolved due to underlying developmental linkages, with the evolution of long robust big toes and short lateral toes for bipedalism leading to changes in hominin fingers. Host-parasite relationships have also been extensively studied in the context of coevolution, as they provide numerous models for observing the phenomenon. Coevolution between hosts and parasites can result in mutual evolutionary influence, with each exerting selective pressure on the other. Reciprocal adaptation between interacting species has been a focus of coevolutionary research, with studies examining macroevolutionary patterns, functional traits, and selection between plants and their herbivores. In test-tube experiments using bacteria and their viruses, coevolutionary "arms races" have been observed, with bacteria becoming resistant to coexisting phage over time.