Monday, February 8 - Deer Valley Unified School District · Monday, February 8 Please copy into...

Monday, February 8Please copy into your agenda:

Monday: Finish Snapchat (due Tuesday)Tuesday: Genetics review (due Wednesday)Wednesday: Genetics quizThursday-Friday: Collect data (dues Tues)

Reminder:-Progress reports & conferences sheets need to be returned asap (4th hour you will get these)

-Knott’s Berry Farm tripDeposit due 2/16 $35 check to Event Source

Mission: We will be incrediblescience students.

How do we get our traits?

Objective of the day...-Explain the basic principles of heredity-Distinguish between dominant and recessive traits-Distinguish between heterozygous and homozygous genotypes

Add to Cells & Genetics Table of Contents

Date Title Page #

2/8 Heterozygous/Homozygous & genetics rules(this will be a piece of notebook paper)

14

Homozygous:

•An organism that has 2 identical alleles for a trait

• Mendel used the word purebred

• Examples: TT or tt

Homozygous genotypes

TT -or- tt

SS -or- ss

GG -or- gg

RR -or- rr

YY -or- yy

PP -or- pp

What trait will these show if they are homozygous?

Homozygous:•These will show the dominant trait if they have 2 dominant alleles and they will show the recessive trait if they have 2 recessive alleles

• Examples: TT = tall or tt = short

Heterozygous:

•An organism that has 2 different alleles for a trait

• Mendel used the word hybrid

• Example: Tt

Heterozygous genotypes

Tt

Ss

Gg

Rr

Yy

Pp

What trait will these show if they are heterozygous?

Heterozygous:•These will show the dominant trait since that allele will mask the recessive allele

• Example: Tt = tall

SpongeBob practice – complete with a partner

HoHoHo HoHe He

Ho HoHo HoHe He

TT, DD, tt, dd, ff, bb, BB, FFBb, Ff, Dd, Tt

yellow yellow blue

square square round

TT -or- Tt tt

PP -or- Pp pp

“Genetics Rules”

• On your paper, write 3 “rules” to help you apply what we have learned so far about dominant and recessive alleles. Think about your vocabulary terms and use your genetics notes. What trait will something that is heterozygous show? What does it take to show a recessive trait? What impact does the genotype have on the phenotype?

Ex: Rule #1 – A homozygous dominant parent cannot produce any offspring that show recessive traits.

“Genetics Rules”

Share your rules with everyone at your table. As you listen to others, you may change or revise your own “rules”

As a group, determine which 2 rules you think are the most important. Write those on the whiteboard. Please write large enough that others can read but small enough that both will fit.

Examples:

Rule #1 – Two purebreds with opposite traits can only produce offspring that show the dominant trait

Rule #2 – 2 recessive parents cannot produce an offspring with a dominant trait

Rule # 3 – An organism that shows a recessive trait must be homozygous

Rule # 4 – Any organism that is heterozygous cannot show the recessive trait and will only show the dominant trait

People don’t spend a lot of time looking at Snapchat messages, so you have to figure out how to get your message across quickly.

Snapchat Assignment

• Due tomorrow

• Create a Snapchat message on paper that SHOWS and TELLS one of your genetics “rules”

• You may use your own rule or one from another table (just make sure to write it down)

• Your Snapchat should include a relevantpicture and also text. The text should be no more than 20 words.

A homozygous dominant parent cannot produce any offspring that show that recessive trait.

RR (R=round, r=wrinkled seed)

Tuesday, February 9Write the date & question:

2/9: If Y=yellow seed color and y=green seed color, then what would be possible genotypes of a homozygous plant? What would be the genotype of a heterozygous plant?

Please get out your homework (SnapChat), but don’t turn it in yet.

Tuesday, February 9Write the date & question:

2/9: If Y=yellow seed color and y=green seed color, then what would be possible genotypes of a homozygous plant? What would be the genotype of a heterozygous plant?

Homozygous: YY or yyHeterozygous: Yy

Share your SnapChat with your teammates at your table.

Make sure that your name is on it and then please turn it in to the basket on the center table.

Reminder:-Progress reports & conferences sheets need to be returned asap (4th hour)


-Review questions due tomorrow (quiz is also tomorrow)



Objective of the day...-Explain the basic principles of heredity-Distinguish between dominant and recessive alleles and compare those to alleles that show incomplete or codominance


Date Title Page #

2/9 Codominant alleles / Incomplete dominanceI will give you this paper

15

Sometimes alleles are neither dominant nor

recessive – this is called codominance or

incomplete dominance

Codominant alleles are written as capital letters with superscripts. With

codominant alleles, both traits are shown.

Example: The color of chicken feathers is controlled by codominant alleles

FB = black feathersFW = white feathers

FB= blackFW = white

Black

FBFB

Black & WhiteWhite

FWFW FBFW

With incomplete dominance we see a blending of traits. For instance, if you cross a red and a white flower you get

a pink one.

R = redW = white

Red

RR

White

WW

Pink

RW

Find someone to talk to

Silently, without talking, please quickly stand up and move to stand with a partner who does not sit at your table.

The partner whose first name comes first alphabetically will be partner A. The other person is partner B.

Take turns reading and answering each question.

1. (partner A) If red (R) and white (W) are alleles that show incomplete dominance, then would a pink flower plant be homozygous or heterozygous? Explain.

2. (partner B) If you crossed 2 pink flowers, then what phenotype(s) could their offspring have? Explain.

3. (partner A) If black feathers (FB) and white feathers (Fw) are codominant alleles, then what would the possible phenotype(s) be of chickens that are homozygous? Explain.

4. (partner B) Using the alleles in question 3, what would a heterozygous chicken look like? Explain.

5. (partner A) Summarize everything you know about codominant alleles.

6. (partner B) Summarize everything you know about incomplete dominance.

Tell your partner thank you and have a seat please – quickly and quietly.

Tell what genotype(s) is/are possible

Use page 13 for pea alleles

Pod color yellow

Seed shape round

Pod shape smooth

Flower color white

Seed color yellow

gg

RR -or- RrSS -or- Ss

ppYY -or- Yy

Tell what phenotypes these create

rr

Ss

PP

Tt

Rr

Wrinkled seeds

Smooth pods

Purple flowers

Tall plants

Round seeds

Tell whether each of these statements is true or false. If it’s false, then tell WHY (or why it’s not possible). If it is true, then provide an example to show how it is possible. Remember that the alleles for pea plants (telling which are dominant and which are recessive) are on page 13 of your binder.

You are not just telling true or false, but instead you are supporting those statements with evidence. Be ready to explain assigned question to the class.

a. Two parents that each show a recessive trait can never produce offspring together that show a dominant trait.

b. Two parents that each show a dominant trait can never produce offspring together that show a recessive trait.

c. A homozygous dominant tall pea plant is crossed with a heterozygous tall plant. There are some tall and some short plants produced.

d. A heterozygous smooth pod plant is crossed with a pinched pea pod plant. It is possible that there are some smooth and pinched pea pod plants produced.

e. We had a pea plant with green pods. We didn’t know if it was homozygous or heterozygous so we crossed it with a plant with yellow pods. Some of the offspring were yellow. Now we know that the green pod parent was homozygous.

f. A pea plant that produces white flowers must be heterozygous. A pea plant that produces purple flowers must be homozygous.

g. If two pink flowers (red and white alleles show incomplete dominance) are crossed, they can only produce other pink flowers.

h. If you had a black chicken and a black and white chicken, they could not produce a white offspring.

Example:

A-Two parents that each show a recessive trait can never produce offspring together that show a dominant trait.

This is TRUE because these parents only have the recessive alleles to pass down. In order to have an offspring that shows a dominant trait, at least one parent needs to have a dominant allele to pass down. Ex: tt + tt cannot make Tt or TT

• Practice active listening while being respectful. This means that you are looking at the speaker and not talking.

• Check your answers as we go. Make changes as needed (or ask questions if you don’t understand).

B-Two parents that each show a dominant trait can never produce offspring together that show a recessive trait.

C-A homozygous dominant tall pea plant is crossed with a heterozygous tall plant. There are some tall and some short plants produced.

D - A heterozygous smooth pod plant is crossed with a pinched pea pod plant. It is possible that there are some smooth and pinched pea pod plants produced.

E - We had a pea plant with green pods. We didn’t know if it was homozygous or heterozygous so we crossed it with a plant with yellow pods. Some of the offspring were yellow. Now we know that the green pod parent was homozygous.

F - A pea plant that produces white flowers must be heterozygous. A pea plant that produces purple flowers must be homozygous.

G - If two pink flowers (red and white alleles show incomplete dominance) are crossed, they can only produce other pink flowers.

H - If you had a black chicken and a black and white chicken, they could not produce a white offspring.

a. Two parents that each show a recessive trait can never produce offspring together that show a dominant trait. True (dominant traits can’t skip generations)

b. Two parents that each show a dominant trait can never produce offspring together that show a recessive trait. False (if they are both heterozygous they can)

c. A homozygous dominant tall pea plant is crossed with a heterozygous tall plant. There are some tall and some short plants produced. False (homozygous dominant parent cannot produce recessive trait in offspring)

d. A heterozygous smooth pod plant is crossed with a pinched pea pod plant. It is possible that there are some smooth and pinched pea pod plants produced. True (both have a recessive allele to pass on)

e. We had a pea plant with green pods. We didn’t know if it was homozygous or heterozygous so we crossed it with a plant with yellow pods. Some of the offspring were yellow. Now we know that the green pod parent was homozygous. False (it must be heterozygous)

f. A pea plant that produces white flowers must be heterozygous. A pea plant that produces purple flowers must be homozygous. False (to show recessive white flowers must be homozygous, to show dominant trait can be either homozygous ore heterozygous)

g. If two pink flowers (red and white alleles show incomplete dominance) are crossed, they can only produce other pink flowers. False (with each having an R and a W allele, they could produce offspring with all 3 phenotypes)

h. If you had a black chicken and a black and white chicken, they could not produce a white offspring. True (both parents would need to have the white allele to pass down and the black chicken does not have it)

• Review homework is due tomorrow. We also have a genetics quiz tomorrow. Study your notes please.

Wednesday, February 10Write the date & question:

2/10 If a person shows a recessive trait, are they homozygous or heterozygous ? How do you know?

Please turn your homework (genetics review questions) into the basket on the center table. Make sure that your name is on it. I don’t need the questions stapled to it.

Choice Board #5 is also due today. Turn that in to the basket on center table as well.

Wednesday, February 10Write the date & question:

2/10 If a person shows a recessive trait, are they homozygous or heterozygous ? How do you know?

Homozygous because they must have 2 recessive alleles to show the recessive trait



-Bandanas - $5



Objective of the day...-Explain the basic principles of heredity-Distinguish between dominant and recessive traits


Date Title Page #

2/10 Genetics quizI will give you both of these papers

16

2/10 Human trait investigation 17

Dominant Traits Investigation

• Background:

Humans have 23 pairs of chromosomes (46 total). We inherit half from our mom and half from our dad. On those chromosomes, we have about 26,000 genes. Those genes, which consist of dominant and recessive alleles, control our traits.


• Question:

Are human traits controlled by dominant alleles more common than those controlled by recessive alleles?


• Hypothesis:Write your hypothesis in your own words.If we survey human traits, then I expect that we will find that ________________, because _________________.

Fill in the blanks – do you think that you will find that dominant traits are more common or that recessive ones are more common or are they in equal numbers? Because = why

Human Inheritance Investigation

Data:

http://askabiologist.asu.edu/mendelian-traits-humans

Survey yourself + 4 other people (who have not been surveyed) by Tuesday at the start of class.

http://askabiologist.asu.edu/mendelian-traits-humans

1. Quiz

2. Read section 4.2 (pages 110-115). Answer the checking your reading and reading visuals questions (except on page 113) as you go and the review questions on page 116. Please answer in complete sentences. There are a total of 11 questions.

Thursday, February 11Same as Friday, 2/12 (4th & 6th hours)

Friday, February 12Write the date & question:

When you toss a coin, what is the chance that it will land on heads?

Friday, February 12Write the date & question:

When you toss a coin, what is the chance that it will land on heads?

50%

• Please turn in your warm-ups to the basket on the center table. Make sure that your name is on them.



-Bandanas - $5 – to team teacher

-Make sure to collect your trait data by TUES (5 total)



Objective of the day...-Identify principles of probability-Predict the outcome of genetic crosses


Date Title Page #

2/12 Probability & Punnett squaresI will give you this paper

18

Coin Toss

PART 1

Please toss the coin 3 times. Record your data in your data table for Part 1.

Calculate the percentage of heads and tails.

Answer the 2 questions.

Coin Toss

PART 2

Please toss the coin 20 times. Record how many times you get heads and how many times you get tails. Then, have someone from the group come up and enter your data into the spreadsheet.

Calculate your percentages and answer the question.

Coin Toss

PART 3

Record the total data from the entire class and answer the question.

Why is it important to collect a lot of data when looking for trends?

Please talk about this at your table and be ready to share your answer with the class.

Probability and Genetics

Probability:

•The likelihood that a particular event will occur

Think About the Coin Toss?• You had a 50% chance of getting heads each time

and a 50% chance of getting tails each time

• The results of one event (toss) did not affect the results of the next event (toss)

• Your data may not have been exactly what you predicted – 50% heads / 50% tails – that’s why this is PROBABILITY

• The more data you collect, the closer your actual results will be to the results predicted by probability

Mendel and Probability:

•Mendel was the first scientist to recognize that the principles of probability can be used to predict the results of genetic crosses

Punnett Square:•A chart that shows all the possible combinations of alleles that can result from a genetic cross

Geneticists use Punnett squares to show all of the possible outcomes of a genetic cross and to determine the probability of a particular outcome.

Example:• In guinea pigs black fur (B) is

dominant to white (b). If you cross a purebred black guinea pig (BB) with a white guinea pig (bb), what is the probability that an offspring will have white fur?

Draw the Square

So…How do you make Punnett Squares?

Back to Pea Plants!!!

•T = tall

•t = short

•Example:

Tt x tt

Draw the SquareThis one is not on your paper –Just watch please

Write the alleles of one parent along the side

Write the alleles of the other parent along the top

Fill in the alleles – this is like a multiplication table

Now you can predict probability:

Tt

tttt

Tt

t

T

t t

2 / 4 are tt (short) = 50% short

Now you can predict probability:

Tt

tttt

Tt

t

T

t t

2 / 4 are Tt (tall) = 50% tall

In pea plant round seeds (R) are dominant to wrinkled seeds (r). If Mendel crossed a heterozygous round seed plant with a wrinkled seed plant, what percent of offspring would you predict to be wrinkled seed plants?

Mendel crossed a purebred tall (T=tall, t=short) plant with a purebred short plant. Show this cross in the Punnett square below. What percent of offspring were likely tall?

Cross 2 white flower plants. Show what percentage of the offspring will be purple and what percentage will be white.

Cross 2 heterozygous yellow seed plants. Show what percentage of the offspring will have yellow seeds and what percentage will have green seeds.

What were the parent’s genotypes?

RR Rr

Rr rr

In pea plant round seeds (R) are dominant to wrinkled seeds (r). If Mendel crossed a heterozygous round seed plant with a wrinkled seed plant, what percent of offspring would you predict to be wrinkled seed plants?

Mendel crossed a purebred tall (T=tall, t=short) plant with a purebred short plant. Show this cross in the Punnett square below. What percent of offspring were likely tall?

What were the parent’s genotypes?

RR Rr

Rr rr

Monday, February 8 - Deer Valley Unified School District · Monday, February 8 Please copy into...

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