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General Biology

Learn the toughest concepts covered in Biology1&2 with step-by-step video tutorials and practice problems by world-class tutors

Table of contents
13. Mendelian Genetics

Non-Mendelian Genetics

1
concept

Polygenic Inheritance

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in this video, we're going to talk about some non Mandelli in genetics or genetics that is not described by Gregor Mendel's laws. And we're going to start off by talking about Polly genic inheritance. And so it turns out that most inherited traits are actually Polly genic. And so what exactly does it mean for traits to be Polly genic? Well, apologetic traits, as their name implies, with the poly route, which means many, and the genic route here, which, of course, is referring to jeans, thes air going to be single fina tippet traits that are affected by multiple genes? And so again, you can see that within the root, apologetic Polly, meaning many or multiple and genic. Of course, referring to the genes and so apologetic traits are single fina tippet traits affected by multiple genes. And so if we take a look at our image down below, over here on the left hand side, notice we're showing you a representation of apologetic trait. One single FINA tippet trait affected by multiple genes. Gene a gene B, gene sea and jean de over here. And so when you have many genes affecting one trait, that is what's referred to as a palla genic trait. Now a classic example of apologetic trait is human height, which is controlled by well over 180 jeans. And so when you take a look at this image down below, you can see that we have different human heights. One at 6 ft, five inches, 6 ft, 5 ft five inches and one at 5 ft. And again, Human height is controlled by well over 180 jeans. And so, uh, that makes it a palla genic trait. Since it's a single trait, Single heat. Human height is a single trait that's affected by multiple genes. And that, of course, is going to be much more complicated than the simple Mandelli in genetics that we've talked about in our previous lesson videos. And so now that we've described, Apologetic Inheritance will be able to compare this to Playa Trophy in our next video, so I'll see you all there
2
Problem

Which of the following phenotypes is an example of polygenic inheritance?

3
concept

Pleiotropy

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So now that we've introduced apologetic inheritance in our last lesson video in this video, we're going to introduced Playa Tropea. And so Playa Trophy is practically the opposite of apologetic, and that's because apologetic means multiple genes affecting one trait. But Playa trophy is when a single gene has effects on multiple different FINA tip IQ treats. And so if we take a look at our image down below, over here on the left hand side, we're showing your representation. Apply a trophy and again, Playa Trophy is when just one single gene has impacts for effects on multiple different traits. Trait A, B, C and D And so again, Playa Trophy is one gene affecting many traits. And a classic example of Playa Trophy is Marfan syndrome, which, ah, mutation of just one single gene. The FBN one gene will limit the body's ability to build connective tissue and lead to a wide variety of FINA tippet traits being affected. And so some Marfan syndrome FINA types include having a tall and slender body, long arms, legs and fingers, curved spine, crooked or crowded teeth, heart disease and heart murmurs and I conditions or vision loss. And so we have one single gene, this Fbn one gene, which, if a mutation occurs, uh, there are effects or impacts in the body the arms, the legs, the fingers, the spine, the teeth, the heart and the eyes, which seemingly might be unrelated. But they are all, uh, traced back to this one particular gene. And so all of these different traits that you see here are all impacted by just one gene. And so that is the idea of Playa Tribbey. And so this here concludes our introduction to Playa Trophy, and we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video.
4
Problem

A pleiotropic genetic disorder typically has what characteristics?

5
concept

Multifactorial Characters

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In this video, we're going to introduce multi factorial characters. And so multi factorial characters are inherited features or FINA types that air influenced by many types of factors. And these factors include genetic factors such as Oh Leal's but also environmental factors such as, for example, the temperature or the pH. And so, in our example down below, we're going to take a look at the effects of the environment, specifically the pH of the soil on flower color fina types of the specific flowers called hydrangea. And so the hydrangea flower color is impacted by the pH of the soil. Not only is it impacted by genetic factors, but it's also again impacted by environmental factors such as the ph of the soil. And so when the pH is acidic, these flowers tend tohave, a bluish type of phenotype. However, when the soil of Ph is mawr basic, then the flowers take on um, or pinkish type of phenotype. And so here. What you can see is that multi factorial characters are going to be influenced by many types of factors genetic factors but also environmental factors as well. And so this year concludes our introduction to multifactorial characters and we'll be able to get some practice as we move forward throughout our course. So I'll see you all in our next video.
6
Problem

Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. This can be best explained by which of the following?

7
Problem

A phenotype is controlled by gene A and gene B. Gene B controls the expression of gene A. This is an example of _____.

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