What is an Allele? Quick Definition
Summary
TLDRIn this 'Quick Definitions' video, John Perry explains the concept of an allele in genetics. An allele is an alternative version of a gene, which can determine traits like eye color in organisms. For instance, a frog might have a 'yellow allele' for its eye color gene, while another frog could have a 'red allele'. Alleles can arise through mutations and compete within a population. If an allele offers a survival advantage, it can become dominant, leading to the fixation of that trait within the population. The video simplifies complex genetic concepts, making them accessible to viewers.
Takeaways
- 🧬 Genes are stretches of DNA that code for specific proteins or serve as templates for functional RNA chains.
- 👁️ An allele is an alternative version of a gene, such as one that codes for a different eye color in a frog species.
- 🐸 Multiple genes and environmental factors often interact to determine an organism's traits, like eye color.
- 🧬 Most animals have two copies of their DNA, meaning they can have two different alleles for a gene.
- 🌱 Most alleles do not affect an organism's observable traits.
- 🔄 New alleles are created through mutations, which can introduce variations into a population's gene pool.
- 🦎 If a new allele provides a survival advantage, it may become more common over generations, potentially leading to the fixation of that allele in the population.
- 🏆 When an allele becomes dominant in a population, it can lead to the extinction of other alleles.
- 👕 The video is from the 'Stated Clearly' series, which provides clear explanations of scientific concepts.
Q & A
What is a gene in genetics?
-A gene is a stretch of DNA that codes for something, either specific proteins or functional chains of RNA, which in turn produce traits in organisms.
How do genes relate to an organism's traits?
-Genes code for proteins and RNA chains that produce traits, such as eye color and bone length, so genes indirectly code for an organism's traits.
What is an allele?
-An allele is an alternative version of a specific gene, which can result in different expressions of a trait, like different eye colors in the example of the frog.
Why are alleles important in genetics?
-Alleles are important because they provide variation within a species, which can lead to different traits and potentially influence survival and reproduction.
How do new alleles come into existence?
-New alleles come into existence via mutations, which are changes in the DNA sequence that can create new versions of genes.
Can an organism have more than one allele for a gene?
-Yes, most animals have two copies of their DNA, meaning a single animal can have two different alleles for any given gene in its genome.
What is the term for when an allele becomes dominant in a population?
-When an allele dominates an entire population, replacing other versions, this is called fixation.
How can an allele provide a survival advantage?
-An allele might provide a survival advantage if it helps an organism better adapt to its environment, such as blending in to avoid predators.
What happens to an allele that does not provide a survival advantage?
-Alleles that do not provide a survival advantage may be outcompeted by other alleles and could eventually become extinct within a population.
Are all alleles observable in an organism's traits?
-No, most alleles do not have any observable effect on an organism's traits, and their influence may be subtle or require specific environmental conditions to manifest.
How does the presence of multiple genes and environmental factors affect an organism's traits?
-Multiple genes and environmental factors can interact in complex ways to determine an organism's traits, making the relationship between genes and traits not always straightforward.
Outlines
🧬 Understanding Alleles in Genetics
The paragraph introduces the concept of an allele in genetics. It explains that a gene is a segment of DNA that codes for proteins or serves as a template for RNA, which in turn affects traits in organisms. An allele is described as an alternative version of a gene. Using the example of a frog's eye color gene, the paragraph illustrates how different alleles (yellow and red eye color alleles) can exist within a species. It also touches on the idea that most animals have two copies of their DNA, allowing for the possibility of having two different alleles for a gene. The paragraph concludes with the concept of allele competition and fixation, where an allele can become dominant in a population, leading to the extinction of other alleles.
Mindmap
Keywords
💡Gene
💡Allele
💡DNA
💡Proteins
💡RNA
💡Traits
💡Mutations
💡Genome
💡Environmental Factors
💡Fixation
💡Heredity
Highlights
A gene is a stretch of DNA that codes for something, usually proteins or functional RNA chains.
Genes indirectly code for traits like eye color and bone length.
An allele is an alternative version of a specific gene.
Alleles can determine observable traits such as eye color in organisms.
The example of a frog with different eye color alleles illustrates the concept of alleles.
In reality, multiple genes and environmental factors contribute to an organism's traits.
Most animals have two copies of DNA, meaning they can have two different alleles for a gene.
Many alleles have no effect on an organism's observable traits.
New alleles arise through mutations.
An allele can provide a survival advantage, leading to its dominance in a population.
The yellow eye allele in frogs might offer better camouflage, enhancing survival.
Over generations, an advantageous allele can outcompete others, leading to fixation.
Fixation occurs when an allele dominates an entire population.
The key takeaway is understanding that an allele is an alternative version of a gene.
John Perry provides a clear definition of an allele in genetics.
Stated Clearly offers new t-shirts for sale, showcasing their brand's presence.
Transcripts
hello you are watching quick definitions
stated clearly what is an allele in
genetics as we've learned in earlier
videos a gene is a stretch of DNA
usually a long stretch of DNA that codes
for something what exactly do genes code
for technically they either code for
specific proteins or they act as
templates for functional chains of RNA
but because proteins and chains of RNA
go on to produce traits things like eye
color and bone length we can say that in
organisms genes in a roundabout way code
foreign organisms traits an allele is an
alternative version of a specific gene
if that sounds confusing that's okay it
should become clear once we see a
simplified example let's say there is a
gene in a species of frog that codes for
the frog's eye color we will call it the
eye color gene no need to get too
creative here this frog has a version of
the eye color gene an allele of the eye
color gene that codes for yellow eyes he
has the yellow allele of the eye color
gene his buddy here has a different
allele a different version of the eye
color gene he has the red allele of the
eye color gene now this hypothetical
example is overly simplistic in real
life there are multiple different genes
and sometimes environmental factors that
all play together to determine an
animal's eye color also most animals
have two copies of their own DNA meaning
that a single animal can actually have
two different alleles or two different
versions of any given gene in its own
genome furthermore most alleles don't
have any actual effect at all on a
creatures observable traits but don't
worry about any of these technicalities
for now the important thing to
understand is this an allele is an
alternative version of a specific gene
that's it new alleles new versions of
old genes come into existence via
mutations once a new allele exists it is
forced to compete with other alleles in
the population for example when the
yelloweye allele happened to emerge
within our hypothetical frog species it
might have given its host a survival
advantage because its host could better
blend into its environment and hide from
predators because of this over many many
generations the yellow allele could
dominate the population completely out
competing the red allele causing the red
alleles extinction when an allele
dominates an entire population we call
this fixation so there you have it an
allele as an alternative version of a
specific gene I'm John Perry and that
was a quick definition of an allele
stated clearly
well what do you know there's brand-new
stated clearly t-shirts for sale I think
I'll buy myself two of them
you
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