Genetics

Genetics

---------Group 1 to 3

I'd like to begin today's lecture by asking you a few simple questions.

Why do people look different from cats, from horses and from birds?

Why do people look different from each other? Why do you look

different from your sister or brother? The answer of all these questions

lies in the genes of people and animals. Your genes provide biological

instructions and control how you look, how you function and even partly

how you behave. Genes determine how every living creature on earth

appears, how it functions, how it reproduces and generally how it behaves.

Now genes are found inside the cells of the body and passed down or

inherited from one generation to the next. You may, for example, have

inherited the color of hair from your mother, or your ability of rolling

tongue from your father, or you may even inherited some other

interesting traits you may or may not be grateful from your great great

great grandfather or grandmother. Who nows? Inherited traits or abilities

are determined by combination of genes that different from every human

being. Although each individual is really quite unique, it's interesting to

know that most genes are coming from every person on earth. In fact,

human share many of the same genes with other kinds or species of

animals from the simple little food fly to our close cousin-the apes. Do

you realize that the small Africa ape called Bloble shares 97% of the

same genes we have. I don't know whether that is a good news or not for

us or for Blobles.

The study of genes is a branch of field of biology called genetics and

scientists who study how genes are inherited and passed down from one

one generation to the next are called geneticist. The field of genetics

actually dates back to the Mid-1800. But most of what we know today

about genetics and about genetic disorders has been learned in only the

last few decades. But don't let me jump ahead to what's going on the

modern genetics before we acknowledge and briefly examine the work of

a pioneering biologist, Gregel Mendel, who lived from 1822 to 1884.

Mendel carried out some of the earliest experiments of genetics by

studying simple pea plant. Between 1856-1863, he grew more than

28,000 pea plants and kept very careful records on these plants. From

these records, he saw clearly there was a particular pattern by which plant

traits or characteristics were passed from one generation of the pea plants

to the next, a pattern that had never been reported before. He explained

the pattern in principles or laws. Today, these principles are known as

Mendel's Law of Heredity. Because we are talking about Gregel Mendel,

let me make it aside and tell you something interesting about Mendel that

ay make him more real to you. In 1851, he was sent to the university in

Vienna to study mathematics and environmental biology, the two subjects

that made him so famous throughout the world. However, after two years

of studying at University Vienna, he left the university. He was extremely

nervous and uptight about taking examinations. It seems that his

extremely nervousness about taking examinations capture him

completing his degree. Now, taking examinations makes everyone

nervous. But apparently, this disability did pour Gregel Mendel in terms

of university studies. However, the examination disability did not stop

him from conducting his research or from becoming one of the most

famous scientists of our time.

Where was I? Eh, yes! I was talking about genes and passing of certain

traits and characteristics from one generation to another. Many of your

individual traits, including the color and shape of your eyes, the texture of

your hair and even your height and weight resemble those of your parents.

Your parents have passed traits onto you and this passing of traits from

your parents to offspring, as we know, is called heredity. From the earliest

ages, people have been interesting in studying and understanding how

heredity works. People have been interesting in learning how they could

all to grow plants, like corn, to give corn the traits that would make the

corn more plentiful and better tasting. And today, they can do that.

Humans also have always been interesting in learning how to improve the

breeding of domestic animals to make them more valuable and useful. In

the case of race horses, for example, owners want to breed strong,

beautiful and fast race horse that can run faster than their competitors'

horse can run. The famous race horse, Cibeseacuit, was offspring or son

of a very famous champion race horse called Made-of-War. Undoubtedly,

Made of War passed traits of strength and speed that help the Cibeseacuit

run faster than many other horses. Even though Cibeseacuit was a small

horse when compared to other race horses he raced. Before DNA was

discovered when Mendel's beginning his experiments, heredity was one

of the greatest mystery of science. Have mentioned much previously,

Mendel studied science in university in Vienna and he tried to use

mathematics to learn how to explain the natural phenomenon. While then,

he studied the work of a man called Night, another early pioneer in the

study of heredity in genetics. Night have crossed or made a variety of the

garden pea that has violet flowers with variety that has white flowers. To

his surprise, he found that all the offsprings of the crossed had only violet

flowers. However, when two of the violet flowers' offspring were

crossbreeded, their offspring produced both violet and white flowers. The

white color trait had reappeared in the second generation of the plant.

Then I was puzzled by this reappearance of the white flowers in the

second generation. And he was unable to explain why did this happen.

Mendel decided to repeat new work on the garden pea plant called( ),but

he decided to apply his knowledge of mathematics and statics to help him

indicate the results or the outcome of the crossbreeding of the white

flowering and violet flowering plants.

Now you might ask why Mendel used the simple garden pea rather than a

rose or some other flowering plants. Also, why he did use a pea rather

than an animal to study the puzzle of heredity? Well, Mendel had a

number of good reasons for choosing to study the pea plants. For one

thing, the plant was available and plentiful when he lived in Austria.

Second, the peas could be copied quickly with little effort. And the most

important, from a mathematician's perspective, the garden pea plant

produced a large number of baby pea plants or offspring. Actually, it

seems the garden pea plant was a very good subject for studying heredity

for several other reasons as well. The garden pea plant has many traits

that have two clearly different forms that's easy to tell apart such as color.

Let me give you an example. The color of a pea plant is either white or

violet. There is no intermediate form of color. Next, the mading of the pea

plant flowers can be easily manipulated. So Mendel was able to control

the mading of the plant easily and observe the offspring of the plants that

resulted from mading. As I mentioned at the beginning of the lecture,

Mendel grew more than 28,000 plants and recorded the many offspring of

these plant. And he did all these counting and record keeping long before

computers were available for record keeping and statics analysis. Just

imagine! We are still benefiting today from early research done by

Mendel. As a result of his research, today we understand much more

about genetics and heredity, though there are so much to be learned. For

instance, these genes are tiny biochemical structures inside each cell that

determine particular heredity traits such eye color, blood type, maybe

intelligence and so on. But we must remember that these genes only give

potentials for the development of particular trait. How this potential is

achieved or realized depends partly on the interaction of genes with other

genes, and depends partly on environment. For example, a person may

have the genetic tendency to be overweight, but the person's actual

weight depends on a number of environmental factors, such as how much

or what kind of food a person eats. Yes, we are what we eat. And thanks

to the factors our ancestors ate and made we are. But it's almost time for

lunch. My hereditary hunger trait must remind me of ending our talking.

Let me and you go to lunch. I'll see you next time!