What is the difference between orthologs, paralogs and homologs?
网页On to the biology. Homology is the blanket term, both ortho- and paralogs are homologs. So, when in doubt use "homologs". However: Orthologs are homologous genes that are the result of a speciation event. Paralogs are homologous genes that are the result of a duplication event.
Why are homologous chromosomes similar? - Biology Stack …
网页4. They are similar because, on average, your genome is 99.9% identical to other humans. So, while there are traceable differences on each chromosome that can be mostly mapped back to each parent, the sequence of the chromosomal pairs is nearly the same. Each chromosome has a specific length and set of genes.
Finding and Comparing Homologous Genes - Biology Stack …
网页2012年5月12日 · There are various databases of homologs, for example: eggNOG. Ensembl Compara (accessible via BioMart, I think) Homologene. OMA. TreeFam. The advantage of using an existing database is that more sophisticated methods for detecting orthologs than simple BLAST searches have been used (see "Computational methods for Gene Orthology inference" for a ...
Can two proteins sharing a few domains be considered …
网页$\begingroup$ This is the definition of homology that disturbed me. you say we must consider global similarity rather than local similarity. accordingly, we can't say these two proteins are homologs, because just about 60% of their lengths have significant (above 80%) similarity and the rest of their sequence is not similar. But actually, we ...
What is the difference between a paralog and an isoform?
网页2020年11月21日 · I have Googled both definitions and paralogs refer to 'genes that derive from the same ancestral genes'. Whereas isoforms refer to 'any of two or more functionally similar proteins that have a similar but not identical amino acid sequence and are either encoded by different genes or by RNA transcripts from the …
What are homologous chromosomes? - Biology Stack Exchange
网页2017年5月6日 · 5. I've read that homologous chromosomes are composed of one maternal chromosome and one paternal chromosome. They have the same size, length, loci and same genes but are not identical. They have different DNA sequences, so contain different alleles. Still, I'm confused if it should be one maternal chromatid and one paternal chromatid.
Are fish and reptilian scales homologous? - Biology Stack Exchange
网页8. No, fish scales are dermal (= formed in derma) bones like skull roof bones. Scales in reptiles are formed by epidermis and are made primarily of protein (from keratinocytes), being similar in derivation to hair, feather and nails. On the other hand, in reptiles one must differentiate between scales and osteoderms (= scutes).
Human somatic cells have 22 pairs of homologous chromosomes?
网页2020年4月25日 · Answer: *Yes , human somatic cells have 22 pairs of homologous chromosomes. The human genome consists of 46 (2n* (22+1) ) chromosomes. Most of our cells are somatic and diploid (2n), they have two homolgous chromosoms (called homologs, one "father" & "mother") these cells multiply by mitosis. Reproductiv cells or …
What is happening in each iteration of PSI-BLAST?
网页2016年6月29日 · 3. Addition to previous answers: PSI-BLAST is a sort of machine learning algorithm which uses the results of the first alignment (PSSM) to score the next iteration of alignment. I would recommend you to refer to the NCBI bookshelf page on PSI-BLAST. PSI-BLAST adopts a scoring scheme (PSSM) that is built …
Chromosomal pair possible in metaphase - Biology Stack Exchange
网页2018年4月15日 · The answer would be 8. The best way to explain this would be by the formula for number of possible arrangements i.e. 2^n. As mentioned in the question, the cell is diploid with 6 chromosomes, which means that 2n = 6 implies n = 3. So number of possible arrangements = 2^3 = 2*2*2 = 8. If the two …