0:01
phenotype A phenotype is the set of
0:03
observable characteristics of an
0:05
organism resulting from the interaction
0:07
between its genetic information and the
0:10
environment The relationship between
0:12
genetics and phenotype is like a
0:14
blueprint becoming a building Your DNA
0:17
contains instructions but how those
0:19
instructions are expressed depends on
0:23
Phenotypes include a wide range of
0:25
observable characteristics such as
0:27
physical traits like height and eye
0:29
color biochemical processes like enzyme
0:31
activity behaviors such as aggression or
0:34
mating preferences and even
0:36
susceptibility to diseases It's
0:38
important to remember that phenotypes
0:40
are what we can directly observe or
0:42
measure while genotypes are the
0:44
underlying genetic instructions that may
0:46
not be immediately visible
0:51
Genotype versus phenotype What do these
0:54
terms mean and how are they related
0:56
Genotype refers to the genetic makeup or
0:58
DNA sequence of an organism It's the
1:00
genetic instructions that determine
1:02
traits Phenotype on the other hand
1:05
refers to the observable characteristics
1:07
or traits that result from the
1:12
genes Let's understand this with a
1:14
simple example of eye color The genes
1:16
that code for eye color represent the
1:19
genotype Different gene variants
1:21
determine whether a person will have
1:22
brown or blue eyes The actual eye color
1:25
we observe whether brown or blue is the
1:28
phenotype the physical expression of
1:33
genes Interestingly different genotypes
1:35
can sometimes produce the same phenotype
1:38
For example in flowers different genetic
1:41
combinations can produce the same red
1:43
color through entirely different
1:48
pathways Conversely the same genotype
1:51
can produce different phenotypes under
1:53
different environmental conditions For
1:56
instance Himalayan rabbits have a
1:58
temperature sensitive gene In warm
2:00
environments they develop white fur all
2:02
over their bodies But in cooler
2:04
environments the same genetic code
2:06
produces dark fur on their extremities
2:08
like ears nose and feet all with the
2:14
code In summary genotype and phenotype
2:17
have a complex relationship While the
2:20
genotype provides the genetic blueprint
2:22
the phenotype what we actually observe
2:24
is influenced by both the genetic code
2:26
and environmental factors
2:32
Environmental factors play a crucial
2:34
role in how genes express themselves The
2:37
same genotype can produce different
2:38
phenotypes depending on environmental
2:42
conditions Environmental factors
2:44
affecting phenotypes can be categorized
2:46
as internal and external Internal
2:49
factors include hormones metabolism
2:51
epigenetic changes and cell signaling
2:53
pathways External factors include
2:56
temperature light diet and nutrition and
3:01
Let's explore specific examples of how
3:03
environment affects phenotypes Nutrition
3:06
significantly affects height Two
3:09
individuals with identical genetic
3:10
potential for height can develop
3:12
different adult heights based on their
3:13
nutritional intake during
3:17
development In many reptile species
3:20
incubation temperature determines the
3:22
sex of offspring The same fertilized
3:25
eggs develop into males at cooler
3:26
temperatures and females at warmer
3:28
temperatures despite identical genetic
3:33
makeup Identical twins provide a perfect
3:36
example of how environment affects
3:38
phenotype Despite having identical DNA
3:41
twins can develop different traits due
3:43
to environmental differences These
3:45
differences can include height weight
3:48
disease susceptibility and even behavior
3:50
patterns all influenced by factors like
3:52
diet exercise and other environmental
3:58
exposures Labrador retrievers provide a
4:01
classic example of how multiple genes
4:03
can influence a single trait Labradors
4:06
come in three main coat colors: black
4:08
chocolate and yellow These colors are
4:10
determined by two different genes
4:14
The first gene is the B gene which
4:16
determines whether the pigment produced
4:18
is black or brown The dominant B al
4:21
produces black pigment while the
4:23
recessive be produces brown The second
4:26
gene is the E gene which controls
4:28
whether pigment is expressed at all The
4:30
dominant EL allows pigment expression
4:33
while the recessive EL prevents pigment
4:36
expression resulting in a yellow coat
4:40
When we combine these genes we can
4:42
understand how different genotypes
4:44
produce the three coat colors Dogs with
4:47
at least one dominant B al and at least
4:49
one dominant EL will have black coats
4:52
Dogs with two recessive B alles but at
4:55
least one dominant EL will have
4:57
chocolate coats And any dog with two
5:00
recessive EL will have a yellow coat
5:02
regardless of their B gene status
5:06
Let's look at how these two genes
5:07
interact to produce a single phenotypic
5:09
trait The B gene determines the pigment
5:12
color while the Egene controls whether
5:14
that pigment is expressed Together they
5:17
determine the final coat
5:19
color In summary the interplay between
5:22
the B gene and the E gene demonstrates
5:24
how multiple genes can work together to
5:26
influence a single phenotypic trait This
5:30
example illustrates an important
5:31
principle in genetics Phenotypes are
5:34
often the result of interactions between
5:36
multiple genes not just a single gene
5:40
alone Genes don't operate in isolation
5:43
Their effects depend on the environment
5:45
they're exposed to This is called gene
5:47
environment interaction Gene environment
5:50
interactions occur when genetic variants
5:53
respond differently to environmental
5:55
factors The same genotype can produce
5:58
different phenotypes depending on
6:00
environmental exposure The interaction
6:02
between genes and environment is complex
6:05
When genes and environmental factors
6:07
interact they produce unique effects
6:10
that can't be predicted by looking at
6:12
either one alone Let's look at our first
6:14
example smoking and lung cancer risk
6:17
Some genetic variants significantly
6:19
increase cancer risk in smokers but show
6:22
little effect in non-smokers Our second
6:24
example involves diet and weight related
6:26
genes The FTO gene variant has been
6:29
linked to obesity but its effects can be
6:31
neutralized by dietary choices These
6:33
examples help explain why genetic risk
6:35
factors don't always lead to predicted
6:38
outcomes Genes don't act in isolation
6:41
Their effects depend on environmental
6:44
context The same genetic variant can
6:46
lead to different outcomes in different
6:50
environments Medical applications of
6:52
phenotype analysis Doctors rely on
6:55
observable symptoms which are phenotypes
6:57
to diagnose medical conditions These
6:59
physical manifestations provide crucial
7:03
clues Genetic testing allows us to
7:06
connect specific genotypes to disease
7:08
phenotypes For example testing can
7:11
identify mutations in genes like Barco 1
7:13
that increase breast cancer
7:15
risk Personalized medicine tailor
7:18
treatment to individuals based on their
7:21
unique phenotypic variations This
7:23
approach recognizes that patients with
7:25
the same disease may respond differently
7:27
to treatments due to their genetic
7:31
makeup Pharmaccogenomics studies how
7:33
genetic differences affect drug
7:36
responses For example variations in the
7:38
SIP 2D6 enzyme gene create different
7:41
metabolizer phenotypes affecting how
7:43
patients process certain medications
7:46
This genetic information allows
7:47
clinicians to optimize drug selection
7:49
and dosing avoiding adverse effects and
7:53
failures This application of phenotype
7:55
analysis is transforming clinical
7:59
practice Phenotypic analysis drives
8:02
crucial applications in agriculture and
8:04
conservation biology In agricultural
8:07
breeding programs farmers carefully
8:09
select for desirable phenotypes to
8:11
improve crop performance These include
8:14
high yield with larger fruits and more
8:16
seeds disease resistance through
8:18
enhanced immune responses adaptation to
8:21
different climates like drought
8:22
tolerance and quality traits such as
8:25
flavor nutrition and shelf
8:27
life Conservation biologists monitor
8:30
phenotypic diversity in wild populations
8:32
as an indicator of genetic health and
8:37
They track population health through
8:39
body condition and size variation assess
8:42
adaptive potential by measuring trait
8:44
diversity and monitor for inbreeding
8:46
effects which typically show as reduced
8:50
variation Modern phenotyping techniques
8:53
now allow for much more precise
8:55
connections between observed traits and
8:57
their genetic basis These include
9:00
phenomics for high throughput trait
9:01
measurement remote sensing using drones
9:04
to monitor crop health genomic selection
9:07
that uses DNA markers to predict traits
9:10
and crisper technology for precise trait
9:13
modification A powerful example of
9:16
phenotype engineering is golden rice
9:18
which demonstrates how understanding the
9:20
connection between genes and phenotypes
9:23
can address global challenges Scientists
9:26
identified vitamin A deficiency as a
9:28
major health problem in developing
9:30
regions By engineering rice to produce
9:32
beta carotene they created a distinctive
9:35
golden yellow phenotype in the rice
9:37
grains This biofortified crop has the
9:40
potential to prevent blindness and death
9:42
in vulnerable populations
