EQ: Where does an organism gets its unique characteristics?

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Fri. 3/1/19 NB PG. 2

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1. Turn to page 2 in your

notebook

2. Make a quick list of

the characteristics you

have of the choices on

the left.

TREE

OBJECTIVE:

Find the most and least common combination of three traits in our class!

PTC paper: In 1931, a chemist named Arthur Fox was pouring some powdered PTC into a bottle. When some of the powder accidentally blew into the air, a colleague standing nearby complained that the dust tasted bitter. Fox tasted nothing at all.

▪ Although PTC is not found in nature, the ability to taste it correlates strongly with the ability to taste other bitter substances that do occur naturally, many of which are toxins.

▪ Plants produce a variety of toxic compounds in order to protect themselves from being eaten. The ability to discern bitter tastes evolved as a mechanism to prevent early humans from eating poisonous plants. Humans have about 30 genes that code for bitter taste receptors. Each receptor can interact with several compounds, allowing people to taste a wide variety of bitter substances.

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1. In your notebook:

2. Ask your partner to identify what characteristic they observe on you.

3. PTC paper will be given to you when you are done with the table and it is written in your notebook.

4. CUT OUT your leaf and write down your initials.

BOYS use dark green leaves and GIRLS use light green leaves.

5. Walk over to the tree and follow the branches. SEE INSTRUCTOR.

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Trait YES NO

PTC PAPER

Attached earlobes

Tongue roller

Textbook page 263-266:

▪ Genetics

▪ Fertilization

▪ True-breeding

▪ Trait

▪ Hybrid

▪ Gene

▪ Allele

▪ Segregation

▪ Gamete

DUE BY Tomorow

Textbook page 267-269

•Probability

•Punnett square

•Homozygous

•Heterozygous

•Phenotype

•Genotype

For the following terms:- write & underline the term-define it-draw and color a picture that represents the term and definition, combined

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EQ: How are different

forms of a gene

distributed to

offspring?

NB pg. 5

Title: "Mendel"

1. What did Gregor

Mendel discover in

the results of his first

experiment?

2. What did Mendel

discover in his

second experiment?

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GREGOR MENDEL

Gregor Mendel as a Austrian monk who was born in 1822. He spent a great deal of time in the monastery garden where he was able to carry out experiments into inheritance. He chose to work with peas, which are small and easy to grow, and produce large number of offspring.

▪ Peas are a “model system.”

▪ •Started with “true breeding” plants

▪ •Trait: specific characteristic (e.g., seed color, plant height) of an individual

▪ •Hybrid: created from cross of true-breeding individuals

Mendel’s different groups of true-breeding plants would produce the same set of traits in each generation.

To figure out how traits were inherited from one generation to the next, Mendel crossed individuals from his true-breeding strains to produce hybrids.

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▪ Mendel did not have our modern understanding of genes and alleles, he did understand that male parts of a flower produce male sex cells (sperm) and that female parts of a flower produce female sex cells (eggs), and that these cells join in the process fertilization.

▪ While offspring are produced from only one parent, each offspring forms from the fusion of male and female cells.

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3 of 9 READ

▪ Mendel removed reproductive structuresfrom pea flowers so that only one set remained.

▪ Mendel was looking at seven characteristics in pea plants. His goal was to look for patterns in the traits across generations.

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▪ Genes: passed from one generation to the next; determine an individual’s characteristics

▪ Alleles: the different forms of a gene

With your partner, complete the following sentences:

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Characteristics such as seed color

are determined by ___________ .

Yellow and green seed colors are

determined by _______ .

The allele for yellow seeds is _______

to the allele for green.

WORD BANK:

Alleles

Dominant

Genes

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PRINCIPLE OF DOMINANCE

▪ Some alleles are dominant, some recessive.

▪ An organism with at least one dominant allele will exhibit that trait.

▪ An organism with a recessive allele will exhibit the trait only in the absence of a dominant allele.

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MENDEL’S F1 CROSSES

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When Mendel

crossed plants with

contrasting traits, the

hybrid offspring

showed traits of

only one parent.

7 of 9 READ

▪ Segregation: separation of alleles during gamete formation

Why didn’t the allele for yellow color show in the F1 generation?

Was the recessive allele for yellow color lost in the F1 generation? How do you know?

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THE FORMATION OF GAMETES

▪ during formation of gametes, or sex cells, alleles segregate from each other so that each gamete carries only a single copy of (one allele for) each gene.

Where are the eggs and sperm?

Where does fertilization occur?

SUMMARY: 15

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NB Pg. 7

EQ: How can we use

probability to predict

traits?

Video Questions:

1. How many chromosomes

do we receive from EACH

parent?

2. What are Punnett squares

used for?

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▪ In your notebook write the table below:

1. You and your partner will take turns flipping a coin. 10 times each.

2. Tally mark (/) the number of times out of ten, that the coin lands on either heads up or tails up on your table/ counter.

Heads Tails

Me

Partner

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PROBABILITY AND HEREDITY▪Probability: the likelihood an event will

occur. If you flip a coin, what is the

▪ probability of either outcome: ________

▪ Three coin tosses? _____________

▪ Each flip is an independent event.

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GENOTYPE AND PHENOTYPE- DRAW A T-CHART

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Two organisms may share the same __________

but have different ______________

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HETEROZYGOUS AND HOMOZYGOUS

▪ Homozygous: has two identical alleles for a gene

▪ Heterozygous: has two different alleles for a gene

▪ Which are:

Homozygous? _______ heterozygous? ______

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1 2 3 4

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6 of 8 READ

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The Two-

Factor Cross

7 of 8 READ

SUMMARY OF MENDEL’S PRINCIPLES▪ Inheritance is determined by units called __________ ,

which are passed from parents to offspring.

▪Where more than one form of a gene for a single trait exists, some alleles may be ______________ and others ______________ .

▪Each adult has two copies of each gene—one from each parent. These genes ____________ from each other when gametes are formed.

▪Alleles for different genes usually segregate ____________ of each other.

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WORD BANK:

Dominant

Genes

Recessive

Independently

segregate

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1. You will work with your

partner next to you.

2. Partner 1 will do 1 and

Partner 2 will do 2 and 4

3. CHECK each others

answers.

4. Be prepared to share

out.

If you do not finish

Spongebob WS, it will be

HW

EQ: What are some exceptions to Mendel's principles?

Feather color in parakeets is controlled by multiple genes

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▪Describe some of the exceptions to Mendel’s principles.

▪Explain the environment’s role in the way genes determine traits.

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▪ 1. What is a polygenic trait? Give an example?

▪ 2. Something new I learned....

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INCOMPLETE DOMINANCE

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▪Some alleles are neither dominant nor recessive.

▪Incomplete dominance: One allele is not completely dominant over another.

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▪The phenotypes for both alleles are clearly expressed.

▪Examples: chicken feather color, human protein controlling blood cholesterol levels

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MULTIPLE ALLELES

▪Many genes exist in more than two forms.

▪Examples: human blood types, fur color in rabbits

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POLYGENIC TRAITS

▪Many traits are produced by the interaction of several genes.

▪Examples: eye color in fruit flies, coat color in dogs, skin color in humans.

▪Traits typically show a wide variety of phenotypes.

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▪Environmental conditions can affect gene expression and influence genetically determined traits.

▪The __________ of an organism is only partly

determined by its ___________________

SUMMARY:32

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Warm-up Activity: (pick up cards in baggie)

1. With your partner, match up the different types of patterns of inheritance cards with the description and example.

2. When you are done, raise your hand.

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1 of 7 no notes

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Differentiate Differentiate between monohybrid and dihybrid crosses

ANALYZE Analyze dihybrid cross using two traits.

Relate Relate to the principle of independent assortment

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1.What is Mendel's

law of segregation

mean?

2. What does

the law

of independent

assortment mean?

DIHYBRID CROSS

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Directions:

1. Pair up!

2. Decide who is Partner 1 and partner 2.

3. Individually complete #1-3

4. Complete #4 together

DIHYBRID CROSS

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Directions:

Now, continue to work on the rest of the problems.

I will check in with you periodically.

Did we accomplish the following:

Relate to the principle of independent assortment

Construct a dihybrid cross using two traits

Differentiate between monohybrid and dihybrid

crosses

Homework: Finish handout by Monday.

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EQ: Why do blood

types matter?

Video Questions:

1. How do antigens

communicate with our

cells?

2. If you inherit an "O" and

an "A" allele, what will

happen?

3. For blood transfusions,

finding the correct blood

type is a matter of life or

death. Explain why.

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HW: READ TXBK pg. 344-345

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Blood

Type

phenotype

Genotype

Can

donate

blood to:

Can

receive

blood

from:

1. Add the table below into your notebook

2. Update your NB with title" Codominance-Blood"

3. As you watch the video, fill in the table.

4. Be ready to answer.

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Purpose: To create a

dragon baby using

genetics!

1. You will need to work

with your elbow

partner!

2. Write your name on

your packet. EVERYONE

will have their own.

3. Watch intro video.

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▪ Write down mom and dad alleles

▪ Determine baby alleles by flipping the popsicle stick.

REMINDER: You cannot take the popsicle sticks home, therefore fill out yur data tables with the designated alleles and do the TRAIT description AT HOME!!!

Tomorrow, you will have an additional day to finish and turn in the packet seperatly from the questions in your notebook

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▪EQ: What patterns of inheritance do human traits follow?

1. Why is it called a sex-linked trait?

2. Why are there more sex-linked traits on the x chromosome?

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KARYOTYPES

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▪A genome is the full set of genetic information that an organism carries in its DNA. The analysis of any genome starts with chromosomes.

▪A karyotype shows the complete diploid set of chromosomes grouped together in pairs, arranged in order of decreasing size.

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SEX CHROMOSOMES

▪ Two of the chromosomes in the human genome are sex chromosomes.

▪ § Females: two X chromosomes

▪ § Males: one X chromosome; one Y chromosome

▪ More than 1400 genes are found on the human X chromosome.

▪ The human Y chromosome contains only about 158 genes.

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AUTOSOMAL CHROMOSOMES

▪The other 22 pairs of non-sex chromosomes are called autosomal chromosomes or autosomes.

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CODOMINANT AND MULTIPLE ALLELES

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The alleles for

many human

genes display

codominant

inheritance.

Ex: Blood Types

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▪The X and Y chromosomes determine sex.

▪The genes located on them show sex linkage.

▪EX: Colorblindness is a sex-linked trait

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Do not say what you see

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X-CHROMOSOME INACTIVATION

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• Female calico cats are tri-colored.

• The color of spots on a Calico cat fur is controlled by a gene

on the X chromosome.

• How many different colors of spots can a male cat

have?

Most genes in one of the X chromosomes are switched off,

forming a region known as a Barr body.

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HUMAN PEDIGREES

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HUMAN PEDIGREES

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A pedigree chart

shows the

relationships

within a family.

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HUMAN PEDIGREES

▪ The information from pedigree analysis makes it possible to determine the nature of genes and alleles associated with inherited human traits.

▪ SUMMARY:

Write a family pedigree of your own using ONE TRAIT. You may have to research whether the trait is dominant or recessive. It needs to have at least 2 generations.

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WARM-UP: Pick up a whiteboard, list the different ways mutations can occur.

Recall our unit about DNA and mutations as well as our Dragon Genetics

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MEIOSIS AND HUMAN GENETIC DISORDERS

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OBJECTIVES:

1. Describe the events that

occur during each phase of meiosis.

2. Identify the differences

between meiosis and

mitosis.

3. Explain the effects of errors in meiosis.

4. Describe how

small changes in DNA affect human traits

▪EQ: What occurs in meiosis and what are the effects of errors in meiosis?

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CHROMOSOME NUMBER

▪ Homologous: chromosomes with the same genes, one originally from each of the organism’s parents

▪Diploid: containing both sets of homologous chromosomes; 2N

▪Haploid: containing only a single set of chromosomes; 1N

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1. What is the goal of mitosis?2. What are the phases?

3. What is the end product?

MEIOSIS

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After the video, we will be able to find out:

1. What is the goal of meiosis?

2. What are the phases?

3. What is the end product?

64TXTBK pgs. 275-278

CHROMOSOMAL DISORDERS: NONDISJUNCTION▪Nondisjunction: when

homologous chromosomes do not separate as they should

▪Gametes with an abnormal number of chromosomes may result.

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DOWN SYNDROME

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The most common form of trisomy,

involving three copies of chromosome

21, is Down syndrome.

- if two copies of an autosomal

chromosome fail to separate during

meiosis, an individual may be born with

three copies of that chromosome

▪Nondisjunction of the X chromosomes can lead to a disorder known as Turner’s syndrome.

▪In males, nondisjunction may cause Klinefelter’s syndrome.

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FROM MOLECULE TO PHENOTYPE

Changes in the DNA sequence of a gene can change proteins:

▪ Altering amino acid sequences

▪ Affecting the phenotype

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How do small changes in DNA molecules affect human traits?

One disorder caused by individual genes is sickle cell disease. sickle-shaped cells are more rigid than

normal red blood cells, and therefore they tend to get stuck in the capillaries

GENETIC ADVANTAGESWhy are these alleles still around if they can be fatal for those who

carry them?

▪ Some alleles that cause disease may also have benefits.▪ Carrying one copy of the sickle cell provides

protection from malaria.▪ Carrying one copy of the Cystic Fibrosis allele provides

protection from typhoid bacterium

Summary:

Extra Credit Opportunity:

CER of this article. It is available on the school website. 69