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Class 10 Biology (India)
Course: Class 10 Biology (India) > Unit 4
Lesson 2: Heredity & Mendel's experiment- Why Mendel chose peas
- Mendel's experiment (monohybrid cross)
- Monohybrid cross
- Dominance & segregation laws
- The law of segregation
- Independent assortment (dihybrid cross)
- Dihybrid cross
- The law of independent assortment
- Mendel's Experiments
- Introduction to heredity review
- Introduction to heredity
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Why Mendel chose peas
Let's explore why Mendel chose peas to study heredity. Created by Mahesh Shenoy.
Want to join the conversation?
- Is it also beneficial for experimentation that pea plants are bisexual i.e. they have both male and female reproductive organs?(7 votes)
- yes, this makes it possible to conduct self fertilisation and determine its genes(4 votes)
- does everyone has same blood type is AA? REEEEE(1 vote)
- There are three kinds of blood groups in humans, namely-
A, B and O, out of which A and B are dominant and O is recessive.
For example, if one of the parents has A blood group and the other one has O, then their offspring will have A
Similarly, if one of the parents has B blood group and the other has O, then their offspring will have B blood group.
However, if one of the parents has A blood group and the other has B, then their offspring will have AB blood group because both A and B are dominant.
A person can have O blood group only if both of his mother and father have O blood group.
Hope it helps :)(6 votes)
- Is speciatio, evolution and classification coming in board exam or is it in deleted syllabus ?(2 votes)
- I think it has been removed for 2020-21. Just heredity, no evolution.(2 votes)
- what is the difference between a character and a trait?(1 vote)
- @ aayeshasaman12 @Mahesh sir says that 4:57
Characters:
Are visible properties. Eg: Height, Colour, Shape
--
And
Traits:
Are the different variations you can get under each character. Eg: Tall or Short in Height.Yellow or Green in color.
Hope this helps. Let me know if you have any doubt
Nolan R.T
:)(3 votes)
- what does it mean to call someone by a monk I don't really understand when you say ( Gregor Mendel who was a monk).(1 vote)
- Mendel's professor recommended Mendel to the Augustinian monks in Brunn (now Brno), who valued science, research, and education. His professor thought he would be a good candidate because of his talent in physics and mathematics. Even though Mendel had not planned to be a monk, he was admitted to the order on September 7, 1843.(1 vote)
- What is the difference between a character and a trait?(1 vote)
- awesome. i never knew they were bisexual(1 vote)
Video transcript
- [Instructor] About a
hundred and fifty years ago a man named Gregor Mendel,
who was actually a monk, raised about twenty-nine thousand
pea plants in his garden. You know peas, right? So he raised so many
of them, not in one go, but over a period of seven to eight years. Why was he so obsessed with peas? Well, turns out he was
trying to find out how traits get inherited
from parents to children. For example, what I mean is, let me get rid of this photo. Suppose, lets say my mom has blue eyes and say my dad has brown eyes. Now the question is, what
color eyes would I get? What would be the color of my eyes? Would it be blue, from my mom? Or would it be brown from my dad? Or would it be a kind of a
mix between brown and blue? So kind of like a brownish-blue eye? Similarly, what about my hair? Would I get straight hair from my mom? Or would I get, would I
get curly hair from my dad? Or, again, would it be some kind of a mix? Like, you know, straighty,
curly, wavy hair. So you see, Mendel wanted
to know exactly how traits gets past on from the
parents to the children. And so for that he said
let's do experiments. Now of course you can't
experiment on humans, that's unethical. And this is why Mendel
first started with mice. He thought he would take mice
with different characters and make them mate, look
at their offsprings, and see if some pattern is there. But that didn't work out. Then he did the same thing with honeybees. That didn't work out as well. The problem is, you can't
control when animals mate, right? You can't do that. And so this is when eventually Mendel turned towards garden peas. He found the peas were
perfect for his experiment. But why peas exactly? Well, let me just write down the reason. This is important, right? This is the main agenda of this video. Why did he take peas? So one of the first important reason why he chose peas because it's a plant. You can control when plants mate. All you have to do is take
pod grains from one plant and put it to another. Right? So, he literally, the mating
was literally in his hands. So he could control
mating, or fertilization. Fer-tee-lize-ation He could control that so that was great. Another important reason
for choosing peas especially is tons of peas have a
very short life cycle. So they have short life cycle. Peas take only about,
uh, three months to grow to their full height. So because of this short
time, you can grow a lot of pea plants and that
means you can do a lot of experiments or a lot of data. In contrast, an apple
tree takes about ten years to grow to it's full length. So apple tree would be
the worst, worst candidate if you want to do a lot of experiments. But if you are really
wondering why just pea plants? Why not any other plant
with short life cycle? Well that's because, and this
is the most important reason, pea plants have a lot of characters. So a lot of characters to experiment with. So they had a lot of characters. What do I mean by this? So let me show you. Let me give you an
examples of what characters I'm talking about. Let me give you an
example of height. Height. Pea plants can either be
tall or they can be short. So the tall ones can grow
up to five to six feet tall. The short ones will be one
and a half to two feet tall. Okay. Another example of the
characters that you can see is in the pea shape itself. You can have pea plants
which have round peas or the ones which have wrinkled peas. Similarly, you can do the
same thing in the color. You can have pea plants
which have yellow seeds, the yellow peas. Or you can have the ones
which have green peas. Another example, you can
have pea plants which have purple flower or you
can have pea plants which have white flower. And there are a couple of
other characters as well. So, anyways these
properties that you can see, we call them characters. Any property which is
visible, all these words, they're officially called,
technically called, characters. And the different variations
you can get in those characters, like tall and short, or round and wrinkled,
they are called traits. Traits, okay? So for example, we could
say, pea color is a character and it has two traits. We could say it has a yellow trait and it has a green trait. And now, you may be
wondering, okay what do you do with all of this? What's the point? The point is, now, what
you can do is, maybe you can take a tall pea plant
and fertilize it with a short pea plant and see
what offspring you get. And you can check how traits gets passed. Or you can take a purple flower plant and cross it with a white
flower plant and see what trait is getting passed. Or maybe you take a short
plant with yellow peas and cross it with a tall
plant with green peas and see then what happens! So, so many different
experiments you can do, right? And by the way another
important, ah, advantage of peas you can see is that all
these characters have just have just two traits. Two contrasting traits. They're tall or short. Yellow or green. Purple or white. Only two traits. But, ah, if you're to take, for example, the human eye color, it
can have three traits. You can have brown or blue or you can have green as well. Think about the human hair color. Think about the human hair types. So many different traits. The more traits you have,
the more complicated our experiments become. The more difficult it becomes
to keep track of them. But if you just have two traits, perfect. And that's why Mendel probably said, for the next seven to
eight years, I'm just gonna grow pea plants after
pea plants in my garden. And that's why he grew so many pea plants. And if you're wondering, after all this hard work, did he find anything? The answer is yes! He did find a pattern
which forms today the basis of genetics. Which is so important
that today, Gregor Mendel is called the Father of Genetics. And we'll get to the
experiments and all the fun stuff in the future videos. But for now, let's recall what we learned in this video. Can you recall, what are
characters and traits? Can you remember, why
Mendel chose pea plants? What are the reasons for that? And can you remember,
or name three characters of the pea plants and
what their traits are? So, great idea to see if
you can recall all this. If you have difficulty in any of this, you can go back and revisit the video. If you are fine with
this, then I'll see you in the future videos.