Are spontaneous mutations rare

Answer 1

Yes, everyone has at least one genetic mutation. No one is perfect.

if they're is an uneven pair of chromosomes in the gene sometimes it cause cancer other times it may cause something known as Down syndrome

Answer 2

The DNA molecule is subject to a wide variety of chemical and physical reactions that can lead to damage and mutation. Furthermore, every time DNA is copied DNA polymerases make many mistakes in synthesizing the new strand, introducing more mutations. However, cells have a huge array of DNA damage and mismatch repair mechanisms that eliminate most mutations before they become a problem. So despite the frequent occurence of DNA damage, mutations are comparatively rare because cells have excellent repair mechanisms.

Another reason why mutations seem rare is that the genome is fairly tolerant of mutations. Diploid organisms have two copies of each gene and in most cases lost of one produces a minimal mutant phenotype. The genetic code is highly redundant, particularly at the third position of the codon. Changes to the third position of a codon often just changes it to another codon coding for the same amino acid so the mutation is silent. In addition, many genetic pathways have feedback and feedforward mechanisms that allow them to compensate for subtle genetic defects in one element of the pathway. And most of the genome is non-coding. So while non-coding DNA isn't just junk, it's a lot more tolerant of small genetic alterations than protein coding DNA. For all these reasons, even when mutations occur, they produce minimal phenotypes and are therefore undetectable except through molecular means, making mutations seem far more rare than they actually are.

Answer 3

They are relatively rare in comparison to induced mutations that are more directed to the physical or chemical properties of DNA.

Answer 4

In humans it's quite rare. Although there are alot of common discoveries and sightings.

Answer 5

Depends on how you define rare.

Answer 6

often