0:01 [Music]
0:04 hi there in today's video we'll be
0:06 talking about how environmental and
0:08 genetic factors can affect how an
0:12 organism grows and develops
0:14 as a review from our previous videos
0:17 we know that genotype refers to the
0:20 organism set of genes or the dna that
0:22 the organism has it gets this from its parents
0:24 parents
0:27 we also know that phenotype refers to
0:29 the organism's observable
0:31 characteristics or traits these are
0:35 things like fur color height of a plant
0:38 color of a flower color of the eye on a
0:40 fly etc
0:43 most importantly we know that the
0:45 genotype is what determines the
0:48 phenotype this means that the observable
0:51 characteristics that an organism
0:54 demonstrates are based on its genes or
0:59 now let's talk about the different
1:02 factors that can affect how organisms
1:04 grow and develop
1:07 based on our review we know that of
1:10 course genetic factors or the genes that
1:12 an organism possesses
1:14 play a role in determining how the
1:16 organism will grow
1:18 some examples of that will look at
1:21 tall people versus short people it is
1:24 safe to assume by observing shaq and
1:26 kevin hart's height phenotypes that they
1:29 have different alleles for the genes
1:32 that dictate height
1:34 another example
1:37 is large breed versus normal cattle
1:40 these are cattle like cows and oxen and
1:42 bulls that are bred
1:45 specifically to select for the genes
1:47 that make the cattle larger that means
1:50 they can produce more meat and more milk
1:53 another example is genetically modified plants
1:54 plants
1:56 you may or may not know that most of the
1:58 fruits and vegetables that you see in
2:00 the grocery store actually are
2:02 genetically modified this means that
2:05 they are bred for genes that cause
2:08 larger more colorful sometimes more
2:11 flavorful fruits and vegetables
2:14 these are some examples of how genetic
2:16 factors or the genes that an organism
2:19 possesses can play a role in dictating
2:22 how the organism will grow
2:24 let's look at an example of a genetic
2:27 factor affecting an organism's growth
2:28 just like we just talked about in the
2:31 previous slide fruits and vegetables
2:34 often are genetically modified we need
2:36 to produce a lot of food to feed a lot
2:38 of people on earth so modern agriculture
2:41 uses genetic modification to create
2:43 plants that produce larger
2:45 and more fruitful
2:48 fruit and vegetable plants corn is no exception
2:53 looking at this data we can see
2:56 but for our three breeds of corn x1 x2
2:58 and x3
2:59 there is a
3:02 impact on the height of the plant and
3:05 the average weight of the ears of corn
3:08 we can see that plant x1 compared to
3:10 plan x2 and x3
3:14 has a lower average height whereas plant x3
3:15 x3
3:17 this breed of corn has a much higher
3:19 average plant height
3:21 we also see that there is a difference
3:23 in the average weight of the corn ears
3:26 with x3 producing
3:27 much larger
3:31 and heavier ears of corn so we can see
3:33 that the different breeds which
3:36 possess a different genotype or a
3:38 different set of alleles
3:41 has an impact or an effect on the growth
3:44 of that organism
3:47 another example is pit bulls you
3:50 probably living in baltimore have seen a
3:52 pit bull or an american pitbull pit bull
3:54 terrier these are a breed of dog that
3:56 are often bred specifically for size so
3:59 some people like the really cute short
4:01 ones that are very muscly
4:03 some people like the much larger much
4:06 stockier versions and then we even have
4:08 some pimples that are sort of a more
4:10 slender uh version well these are
4:12 varieties of people that are bred to
4:14 have different genes
4:17 we can have pocket standard and xl pit
4:19 bulls that all have a different set of
4:23 genes which we see can have an effect on
4:26 their growth with the pocket versions of
4:28 the pit bulls weighing only an average
4:31 of 45 pounds and the xl's getting up to
4:34 about 80 pounds that is a big pit bull
4:36 we also can see that these different
4:39 genes have an effect on the body fat
4:42 percentage with the larger xl variety
4:45 having a much lower body fat percentage
4:48 than the other two probably resulting in
4:52 a much stockier and more muscular dog [Music]
4:54 [Music]
4:56 now let's talk about the other factor
4:58 that can affect the growth of organisms
5:02 this is environmental factors so the
5:05 environment that an organism lives in
5:07 also plays a role in determining how
5:09 that organism will grow
5:11 you may have heard the saying nature
5:13 versus nurture
5:15 in this case the genes that the organism
5:18 possesses is its nature whereas the
5:21 environment that the organism is in is nurture
5:23 nurture
5:25 let's look at some examples of how
5:27 environment can affect the growth of organisms
5:28 organisms
5:31 so first we know that the amount of
5:34 light water fertilizer and other factors
5:38 that's provided to a plant can impact a
5:40 plant's growth so if we look at this example
5:41 example
5:43 we can see
5:46 that this plant has grown a lot taller
5:48 than this plant even though they seem to
5:50 be exactly the same breed of plant
5:52 meaning the same genes that's because
5:54 these taller plants were provided more
5:57 water whereas these shorter plants were
5:59 provided less water that's a change in
6:02 the environment which has then resulted
6:06 in an effect on how that plant has grown
6:08 another factor that is environmental and
6:11 can impact growth is how much and the
6:13 type of food that a person or animal is
6:16 fed so here we can see an example where
6:19 this lion has clearly been underfed and
6:22 malnourished and this lion has been fed
6:24 a healthy diet of the right kinds of
6:26 meats and proteins
6:29 type of food and how much food can also
6:31 be an environmental factor
6:33 that affects
6:35 another example
6:37 is the size or amount of space of a
6:39 habitat that's provided to a plant or animal
6:40 animal
6:43 for instance if i take a goldfish and
6:45 put it in a very very small bowl from
6:48 the time it's born until adulthood
6:50 it will actually be stunted in its
6:53 growth whereas if i put the same breed
6:55 of goldfish into a larger tank i will
6:58 see that it actually grows to a larger
7:01 size showing me that the size of the
7:03 habitat is an environmental factor that
7:05 can impact growth
7:07 let's look at some examples now of
7:09 environmental factors affecting the
7:11 growth of organisms
7:13 so in this case we see a gardener has
7:15 planted three of the exact same type of
7:17 plant spider plant that means it has the
7:18 same dna
7:20 however he's provided each with
7:21 different amounts of water and fertilizer
7:23 fertilizer
7:25 looking at our data we can see that
7:29 plant a was provided a very small amount
7:31 of water and no fertilizer at all
7:34 plant b was provided more daily water
7:37 and more fertilizer and plant c was
7:40 provided lots of water and ample amount
7:41 of fertilizer
7:44 and here we can observe that has had an
7:47 effect on the growth of the plant with
7:49 plant c the one that was provided enough
7:52 water and fertilizer growing much more
7:58 another example is koi fish one thing
8:01 that's interesting about koi fish is
8:04 they will continue to grow indefinitely
8:05 indefinitely
8:07 based on the size of the environment
8:10 that they're placed in so here we can see
8:10 see
8:13 the three different ponds with three
8:15 different sizes
8:18 have different average sized koi fish we
8:20 can assume that they're all coy meaning
8:24 they have the same genes or the same dna
8:27 but clearly the average growth of these
8:29 fish has been affected looking at our
8:32 data we can see that that is based on
8:34 the size of the habitat
8:37 with the fish given a very very small
8:40 area to swim and to grow in growing
8:42 only eight inches that's a pretty small koi
8:43 koi
8:46 whereas the fish placed in the large
8:49 pond with ample square footage and room
8:53 to swim and grow growing a massive 18
8:55 inches another example of how
8:57 environment can impact growth and
8:59 development of an organism [Music]
9:01 [Music]
9:03 finally let's talk about how genetic and
9:05 environmental factors affect organisms
9:07 growth so like we said nature versus nurture
9:08 nurture
9:11 it's not just one that's causing
9:14 the outcome on growth and development
9:17 growth is influenced by both genetic and
9:19 environmental factors simultaneously or
9:21 at the same time this means that the
9:23 growth of an organism is a result of
9:26 both the genetic and the environmental
9:28 factors working together
9:30 let's look at an example
9:31 so here we can see three trees these are
9:35 all apple trees looks like tree one and
9:37 tree two
9:39 are shorter than tree three
9:42 here i can see that tree one is a dwarf variety
9:43 variety
9:45 whereas two and three are standard trees
9:48 that means that one has different dna or
9:51 different genes than plants two and three
9:52 three
9:54 now i also can see
9:58 that plant one and plant three were
10:00 provided normal amounts of water whereas
10:02 plant two
10:06 was provided less water than it needs
10:07 so now let's look at our data and see
10:09 how this makes sense
10:13 so comparing plant one and two i can see
10:15 that plant two has grown taller than
10:17 tree one
10:19 this is because
10:22 of its genes the dwarf tree has genes
10:26 that tell it to grow shorter
10:29 however if we compare trees two and
10:32 three these are both standard apple tree
10:34 varieties so why have they grown
10:35 different if they both have the same set
10:37 of dna
10:39 now we look at the environmental factor
10:41 that's coming into play here which is
10:42 the amount of water they've been provided
10:43 provided
10:46 here we see that plant 2
10:48 has been provided less water than it
10:51 needs to grow and thrive hence resulting in
10:52 in
10:54 less growth than
10:57 plant 3 which is also a standard variety
