how do they come about, how can they kill organisms
In: 1
An allele is the part of an organism’s genetic code that controls or strongly influences a particular trait, or set of traits, in that organism.
Many alleles come in pairs. One comes from the organism’s mother, and one from the father.
If one of those alleles is faulty, typically through a mutation where one or more of the DNA pairs gets changed or corrupted, the other allele can often allow the organism to continue onwards as normal, or at least to survive, even if hindered in some way.
If both alleles are faulty, however, and that allele happens to be critical to the survival of the organism, then the organism dies.
It’s not so much that lethal alleles “kill” organisms, it’s more that tens of thousands of things have to go right for an organism to grow and live in the first place, and a critical failure somewhere will bring that process grinding to a halt.
Answer:
Alleles are differences in how genes are coded in DNA. A large number of genes are considered robust because most small transcription errors actually produce either the same proteins (completely the same) or don’t fundamentally change the way a protein operates.
However if the transcription errors arise in critical positions in a protein that is critical to life function, for example the active site of a protein or a critical directing amino acid that controls how the active site is situated, than these alleles can be considered lethal. These lethal alleles can keep life from starting or will create a situation where life will end faster because the protein(s) are either poorly or non-functional.
Not the answer, but more of a result of study: I was always thought lethal alleles were genetic mutations that build up over time and result in the end of an organism’s lifespan. Like, it’s the reason we’re not immortal. Thanks for bringing this up. Sorry to all the people in my life that believed me when I said that…
Alleles are versions of genes.
Say, a flower-bearing plant will have a gene that encodes a bright yellow pigment protein in its leaves. But there’s also an allele of that gene that results in orange pigment. Or yet another different allele that doesn’t encode functioning pigment at all.
If that latter situation happens with a pigment gene, you might end up with colorless leaves, but an otherwise living plant. But what if the gene encoded something that was vital for life and/or development? Then that particular allele would be incompatible with life. Having it would be lethal.
Five year old version; Imagine you’re trying to drink a Slurpee using two straws, one your mom gave you and one your dad gave you. Oh no! One of your straws has a hole in it! That’s ok, you still have another. Now imagine both your straws have a hole in them. You can’t drink the Slurpee of life now!
If you have one damaged straw and one normal one, you’re ok. When your kids asks for a Slurpee with two straws though, you have a 50/50 chance of giving them the broken one. If your partner also has a broken straw, your kid has a chance of not getting to drink any Slurpee if you both give them broken ones. But as long as everyone has at least one good straw they’re ok.
Latest Answers