warm-up answer the following questions in complete sentences! 1.what are traits? 2.what are genes?...

Father Mother

Eyes

Mouth

Nose

Ears

Hair

Use the table below to answer question about yourself in comparison to your parents. Place check mark to which one you resemble the most. You must draw this table in your journal

Warm-Up Answer the following questions IN COMPLETE SENTENCES!

1.What are traits?2.What are genes?3.Where are genes found?4.What are offspring?5.How do parents pass down there genetic information to their offspring?

When a person is an 'albino', they have very pale (almost white) skin, hair, and eye color. Yet, skin color, eye color, and hair color are controlled by 3 different genes. How do you think a single mutation in a person can cause all three of these traits to be affected?

Journal Warm up

Essential Question: How do children inherit traits from their parents?

The Basics of GeneticsThe Basics of Genetics


1. Traits are passed or inherited 1. Traits are passed or inherited from one generation to the next.from one generation to the next.


What part of your cells contain your What part of your cells contain your genetic instructions?genetic instructions?

Your genetic instructions are located in the nucleus of Your genetic instructions are located in the nucleus of every cell, stored within every cell, stored within chromosomeschromosomes..


How will your traits be passed on to How will your traits be passed on to your future children?your future children?

Fathers pass genetic Fathers pass genetic instructions to offspring instructions to offspring through through spermsperm cells. cells.

Mothers pass genetic Mothers pass genetic instructions to offspring instructions to offspring through through eggegg cells. cells.


Chromosomes: How many? Chromosomes: How many? Where are they? Where are they?

A human body cell A human body cell contains contains 4646 Chromosomes, which Chromosomes, which are stored inside every are stored inside every cell’s cell’s nucleusnucleus..

Human sex cells (sperm Human sex cells (sperm or egg) contain or egg) contain 2323 chromosomes each.chromosomes each.


2. Traits of an organism are 2. Traits of an organism are controlled by controlled by genesgenes..

A gene is a section of a A gene is a section of a chromosomechromosome, that , that codes for a specific trait.codes for a specific trait.

ChromosomesChromosomes are are made of tightly wound made of tightly wound strands of strands of DNADNA and and proteins.proteins.

genegene


3. Organisms inherit genes 3. Organisms inherit genes in pairsin pairs, , one from each parent.one from each parent.

Human sex cells (sperm or Human sex cells (sperm or egg) contain egg) contain 2323 chromosomes each. chromosomes each.

When the egg is fertilized, When the egg is fertilized, the new baby will have the new baby will have 46 46 chromosomes in each of its chromosomes in each of its cells, which is the correct cells, which is the correct number of chromosomes for number of chromosomes for a human.a human.


Sexual Reproduction Sexual Reproduction (2 parents) creates unique offspring.(2 parents) creates unique offspring.

In plants, male In plants, male chromosomes are chromosomes are passed through passed through pollenpollen grains to female grains to female egg egg cells. Once cells. Once fertilized, these eggs fertilized, these eggs will develop into will develop into seedsseeds..

The new plants will The new plants will receive a combination receive a combination of traits from both of traits from both parents.parents.


4. Some genes are 4. Some genes are dominantdominant, , while others are while others are recessiverecessive..

““Stronger” traits are Stronger” traits are called called dominantdominant. .

““Weaker” traits are Weaker” traits are called called recessiverecessive..

Geneticists use Geneticists use symbols symbols (letters)(letters) to to represent the represent the different forms of a different forms of a gene. gene.


DominantDominant traits are traits are represented by a represented by a capital lettercapital letter..

Yellow seeds are Yellow seeds are dominant……..dominant……..

YY


RecessiveRecessive genes (for the same trait) genes (for the same trait) are represented by are represented by THE THE

SAMESAME lower caselower case letter. letter.Green seeds are Green seeds are

recessive……….recessive……….

yyDominant (yellow) = YDominant (yellow) = Y

Recessive (green) = yRecessive (green) = y


In pea plants, In pea plants, tall is dominant tall is dominant over short. The over short. The letter used to letter used to represent the represent the tall tall gene is gene is TT. .

The The shortshort gene is gene is represented by represented by tt..

Tall =TTall =T

Short = Short = tt

Tall =TTall =T

Short = Short = tt


In humans, brown eyes are In humans, brown eyes are dominant over blue. dominant over blue.

Brown = BBrown = B

Blue = bBlue = b


5. 5. Dominant genes hide recessive Dominant genes hide recessive genesgenes when both are inherited by an when both are inherited by an organism.organism.

Y + y = yellow seeds Y + y = yellow seeds

(yellow is dominant)(yellow is dominant) T + t = tall plant T + t = tall plant

(tall is dominant)(tall is dominant) B+ b = brown eyes B+ b = brown eyes

(brown is dominant)(brown is dominant)


A A PUREBREDPUREBRED organism has two of organism has two of the same genes for a trait. the same genes for a trait.

TT = TT = purebredpurebred TALL TALL tt = tt = purebredpurebred SHORT SHORT


A A HYBRIDHYBRID organism has two organism has two different genes for a trait.different genes for a trait.

Tt = hybrid TALL Tt = hybrid TALL (tall is dominant.)(tall is dominant.)

Bb = hybrid for black Bb = hybrid for black feathers (black is feathers (black is dominant.)dominant.)


Will a Will a hybridhybrid human with the genes human with the genes Bb have brown or blue eyes? Bb have brown or blue eyes?

Bb = Brown eyes Bb = Brown eyes The dominant gene (brown), will be expressed The dominant gene (brown), will be expressed

in a hybrid.in a hybrid.

Why must all blue eyed people be Why must all blue eyed people be PUREBREDPUREBRED for that trait? for that trait?

If the dominant gene is present, it will always be If the dominant gene is present, it will always be expressed.expressed.

The only possible gene combination for blue eyes is The only possible gene combination for blue eyes is

bb.bb.


6. Some genes are neither dominant 6. Some genes are neither dominant nor recessive. These genes show nor recessive. These genes show

incomplete dominance.incomplete dominance. If an organism shows If an organism shows

INCOMPLETE INCOMPLETE DOMINANCEDOMINANCE for a trait, the for a trait, the hybrid will show a blend of hybrid will show a blend of the two traits. the two traits.

In humans, hair texture is In humans, hair texture is such a trait. such a trait.

Because neither curly or Because neither curly or straight hair is recessive, straight hair is recessive, no no lower case letters are used.lower case letters are used.

CCCC = curly hair = curly hair

CSCS = wavy hair = wavy hair

SSSS = straight hair = straight hair

These basic laws of inheritance These basic laws of inheritance control the traits of all living control the traits of all living

organisms on Earth. organisms on Earth.


warm-up answer the following questions in complete sentences! 1.what are traits? 2.what are genes?...

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