Regulation of lactase gene worksheet answers

Each "word" or codon in the mRNA language consists of how many letters?

Group of answer choices

5

2

4

3

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Question 20.5 pts

The "start" codon is

Group of answer choices

UGA

UAU

UUU

AUG

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Question 30.5 pts

The first step in translation is

Group of answer choices

elongation

termination

translocation

initiation

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Question 40.5 pts

If the DNA triplets were ATG-CGT, the mRNA codons would be

Group of answer choices

ATGCGT

UACGCA

UAGCGU

AUGCGU

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Question 50.5 pts

What form of RNA carries amino acids to the growing protein chain?

Group of answer choices

messenger RNA

all of them

transfer RNA

ribosomal RNA

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Question 60.5 pts

The process where RNA is translated to a protein is called

Group of answer choices

RNA replication

DNA replication

transcription

translation

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Question 70.5 pts

Translation ends when

Group of answer choices

a stop codon is reached

the tRNA can't find anymore amino acids

an AUG codon occurs

the mRNA falls off the ribosome

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Question 80.5 pts

Amino acids are strung together to form ___________________.

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Question 90.5 pts

Nearly all living things use the same genetic code.

Group of answer choices

True

False

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Question 100.5 pts

Which position of the codon (called the wobble position) can often vary and not change the amino acid that it codes for?

Group of answer choices

third

first

second

any position

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Question 110.5 pts

For 18 of the 20 amino acids, more than one codon codes for the same amino acid. What feature of the genetic code does this represent?

Group of answer choices

complimentary

universal

orderly

degeneracy

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Question 120.5 pts

Hemoglobin is a protein that is made up of two pairs of polypeptide chains. This is an example of ___________ level of protein structure.

Group of answer choices

primary

secondary

quaternary

tertiary

All genes in all cells are being transcribed (converted to mRNA) all the time.

Group of answer choices

True

False

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Question 20.5 pts

Gene expression is tissue specific.

Group of answer choices

True

False

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Question 30.5 pts

What does it mean for a gene to be "on"?

Group of answer choices

it is being translated

the chromosome is being replicated

it is being transcribed

it is being mutated

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Question 40.5 pts

Which of the following is not a way that the cell controls transcription?

Group of answer choices

DNA accessibility

regulation from other genes

signals sent to genes by way of hormones

formation of ribosomes

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Question 50.5 pts

Keeping the DNA tightly packaged can prevent transcription of genes.

Group of answer choices

True

False

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Question 60.5 pts

________________ are proteins that prevent transcription by binding to the DNA sites that transcription activators would normally use when the gene is on.

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Question 71.5 pts

Match the type of gene with how it controls other genes with respect to transcription

Group of answer choices

enhancers

silencers

insulators

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Question 80.5 pts

Hormones can can affect genes in many different tissues at the same time.

Group of answer choices

True

False

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Question 90.5 pts

The only way to control gene expression is by controlling its transcription.

Group of answer choices

True

False

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Question 100.5 pts

How can a single gene code for numerous different proteins?

Group of answer choices

this statement is false - genes always just code for one protein

genes can code for different proteins depending on what type of cell they are in

the tighter the DNA is coiled, the more proteins the gene can code for

variations in how the mRNA molecule is edited after transcription

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Question 110.5 pts

What controls how many times a mRNA molecule can be translated before it is destroyed?

Group of answer choices

the position of the cap

the number of exons

the number of introns

the length of the poly A tail

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Question 120.5 pts

Cells have the ability to control where and when translation occurs.

Group of answer choices

True

False

Genetics and Society

Ch. 9 - RNA Structure and Transcription

Answer the following questions in your own words.

1. List three differences between RNA and DNA. (3 pts)

1. List the three types of RNA and describe their functions. (3 pts)

1. What is the purpose of transcription? (1 pt)

1. What is the function of the enzyme, RNA polymerase? (1 pt)

1. How does the transcription initiating machinery know where to start transcription? (1 pt)

1. If a DNA strand had the nucleotide sequence -ATGCGGCTAGAATATTCCA-what would the sequence of the complementary mRNA strand be after transcription? (1 pt)

1. Describe three ways that the mRNA molecule is modified after transcription stops. In your description, include the purpose of each modification. (3 pts)

1. Where is the mRNA molecule going after it leaves the nucleus? (1 pt)

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Ch. 10 – Translation

Answer the following questions in your own words.

1. In biology, what is the purpose of translation?

2. Where in the cell does translation take place?

3. How does the cell know where to begin translating the mRNA?

4. How does the cell know where to stop translating the mRNA?

5. Define codon. Include its function in the definition.

6. Fill in the blanks:

Proteins are made up of subunits called _____________ ___________ and there are __________ of these subunits found in nature.

7. The genetic code is described as degenerate. What does this mean and why is it beneficial?

8. The virus that causes Covid-19 is an RNA virus. This means that its genome is composed solely of RNA. Many of the vaccines being developed to prevent Covid-19 infections are actually segments of RNA that code for specific viral proteins. Vaccine recipients will be injected with these RNA segments and their cells will make the viral proteins that this RNA codes for.

a. What process will the cell use to do this?

b. Where in our bodies must the RNA segments get delivered to in order for this process to happen?

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DNA RNA Protein

Below are four problems where you will practice transcription and translation. Remember that when you transcribe DNA to RNA, you follow the base pair rules but you replace T with U. This worksheet will review the processes of transcription and translation and introduce the concept of how mutations (changes in DNA sequence) can affect the proteins that the DNA codes for.

1. Below is a section of the gene that codes for normal hemoglobin. Transcribe this section of DNA into mRNA (ch. 9) and then translate the mRNA into the correct sequence of amino acids. (ch. 10) *Note this is just a section so there is no stop codon

There is a copy of the genetic code on the last page of this worksheet. You can use the 3 letter abbreviations for the amino acids.

DNA: TAC CCT GAC TGA GGA CTC CTC TTC AGA

mRNA:

amino acid sequence:

1. Sickle Cell disease can result from a single mutation in the above DNA sequence. The underlined thymine above is changed to a C below. Transcribe this section of DNA into mRNA and then translate the mRNA into the correct sequence of amino acids. Answer the question below.

Mutated DNA: TAC CCT GAC TGA GGA CCC CTC TTC AGA

mRNA:

amino acid sequence:

What happens to the amino acid sequence because of this change from a T to a C?

1. Mutations can occur at any position in the DNA sequence. Below is the normal DNA sequence and then a mutated sequence (the highlighted C is changed to a T). Transcribe and translate the mutated sequence and compare it to the normal sequence that you transcribed and translated in problem #1 above. Answer the questions below.

Normal DNA: TAC CCT GAC TGA GGA CTC CTC TTC AGA

Mutated DNA: TAC CCT GAC TGA GGA CTT CTC TTC AGA

mRNA:

amino acid sequence:

What happens to the amino acid sequence because of this change from a T to a C?

Is it likely that this mutation will lead to sickle cell disease? Why or why not?

Bonus question (up to 5 pts)

Sometimes mutations occur so that a nucleotide is removed from a DNA sequence. In the mutated sequence below, a nucleotide has been deleted due to a mistake during DNA replication. Transcribe this section of DNA into mRNA and then translate the mRNA into the correct sequence of amino acids. Answer the questions below.

Mutated DNA: TAC CCT GAC TGA GGA CCC TCT TCA GA

mRNA:

amino acid sequence:

How did the mRNA sequence change because of this deletion?

How did the amino acid sequence change because of this deletion?

Is it likely that this mutation will lead to sickle cell disease? Why or why not?

Image result for genetic code table

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Ch. 11 Gene expression – Lactose tolerance activity

Watch the following HHMI documentary, “Got Lactase? The Co-evolution of genes and culture” about evolution of lactose tolerance. As you are watching the video, answer the following questions.

https://www.hhmi.org/biointeractive/making-fittest-got-lactase-co-evolution-genes-and-culture

1. All infant mammals can digest milk. T/F

2. What does the enzyme, lactase do?

3. Why are so many human adults lactose intolerant?

4. Why is lactose tolerance also called lactase persistence?

5. Worldwide, what percentage of human adults can digest milk?

6. Lactase persistence is prevalent in many areas of the world. T/F

7. Did researchers find a difference in the lactase gene between lactose tolerant and lactose intolerant people?

8. Think about it… What would be a possible effect of a mutation in the coding region of the lactase gene?

9. Where in the genome does the mutation occur that leads to lactase persistence?

10. What is a pastoralist?

11. Briefly explain how scientists determined that people in Africa and European settlements were using diary as a food source.

12. Provide two reasons why a mutation that led to lactase persistence would be a selective advantage in populations that used milk as a food source.

13. You are talking to your friend and they say, “I can’t eat ice cream because I don’t have the gene for the enzyme, lactase.” Explain why this statement is not correct. Provide a statement that would be correct and explain why a person might not be able to eat ice cream.

14. In your own words, explain how lactose intolerance is the result of a difference in gene expression.