Which of the following demonstrates the central dogma of molecular biologists?(1 point)

Question

A. DNA and RNA hold the code to create proteins that are the key to gene expression.
B. Gene expression relies on environmental factors that determine which traits are dominant.
C. DNA and RNA mutate into either harmful or helpful effects on the human body.
D. Proteins replicate DNA which gives the expression of traits to an organism.

Answer 1

A. DNA and RNA hold the code to create proteins that are the key to gene expression.

This option best demonstrates the central dogma of molecular biology, which describes the flow of genetic information from DNA to RNA to proteins.

Answer 2

What type of mutation is shown below?

DNA Sequence: TTA-GCG-ATC
Copy of DNA Sequence: AAC-TCG-CTA-G

(1 point)
Responses

Substitution
Substitution

Inversion
Inversion

Insertion
Insertion

Deletion

Answer 3

The mutation described in the provided sequences is an Insertion.

In the given DNA sequence (TTA-GCG-ATC) compared to the copy (AAC-TCG-CTA-G), there is an extra segment "CTA" that appears in the copy, which indicates that nucleotides have been inserted into the sequence.

The original sequence has a total of 9 nucleotides (TTA-GCG-ATC), while the copy has 12 nucleotides (AAC-TCG-CTA-G), showing that nucleotides have been added.

Therefore, the correct answer is Insertion.

Answer 4

Look at the DNA sequence.

C G T T A C T G C A A T
G C A A T G A C G T T A
Which sequence shows a substitution mutation?

(1 point)
Responses

C G T C T A C T G C A A T
G C A G A T G A C G T T A
C G T C T A C T G C A A T G C A G A T G A C G T T A

C G T A C T G C A A T
G C A T G A C G T T A
C G T A C T G C A A T G C A T G A C G T T A

C G T T A C T G C A A T
G C A A T G A C G T T A
C G T T A C T G C A A T G C A A T G A C G T T A

C G T G A C T G C A A T
G C A C T G A C G T T A

Answer 5

To identify the substitution mutation, we need to find a sequence where at least one nucleotide in the original DNA sequence has been replaced with a different nucleotide.

Let's analyze the options you provided:

1. C G T C T A C T G C A A T
   G C A G A T G A C G T T A

   • Here, the third nucleotide (T) from the original first sequence is replaced by C, and the fourth (A) in the second sequence is replaced by G.
   • This shows substitutions.

2. C G T A C T G C A A T
   G C A T G A C G T T A

   • Here, the third nucleotide (T) from the original is replaced by A, and in the second sequence, the fifth nucleotide (A) is replaced by T.
   • This indicates substitutions as well.

3. C G T T A C T G C A A T
   G C A A T G A C G T T A

   • No changes in this option; it’s identical to the original.

4. C G T G A C T G C A A T
   G C A C T G A C G T T A

   • Here, the third nucleotide (T) from the original first sequence is replaced by G, and the second (A) in the second sequence is replaced by C.
   • This also shows substitutions.

Based on this analysis, all options 1, 2, and 4 show substitution mutations.

However, it seems you're looking for only one that explicitly highlights a substitution. To narrow it down, the first two sequences showcase clear substitutions on both strands but the last one handles a substitution at a broader aspect.

To finalize:

• Option 1: C G T C T A C T G C A A T / G C A G A T G A C G T T A and Option 2: C G T A C T G C A A T / G C A T G A C G T T A are the clearer candidates for substitution mutations as they reflect changes specifically.

But, if forced to select one, Option 1 is a clearer example of a substitution mutation on both strands.

Please confirm which format I should base the final answer on!

Answer 6

Which of the following best describes how a liver cell and skin cell have the exact same DNA sequence and yet look different and perform different functions?(1 point)
Responses

The tRNA uses a different sequence in each cell during transcription.
The tRNA uses a different sequence in each cell during transcription.

The cells mutate during transcription.
The cells mutate during transcription.

The proteins are expressed differently in each cell.
The proteins are expressed differently in each cell.

The cells discard the DNA that is not in use.

Answer 7

The best answer to describe how a liver cell and a skin cell can have the exact same DNA sequence, yet look different and perform different functions is:

The proteins are expressed differently in each cell.

This option reflects the concept of gene expression, where different genes are turned on or off in different cell types, leading to the production of different proteins that determine the cell's characteristics and functions.

Answer 8

Stella described protein synthesis as a process that makes the necessary proteins for the human body to function. She explained the process in the following steps.

DNA is transcribed into mRNA.
Amino acids form a chain.
The amino acid chain is folded into a protein in the endoplasmic reticulum.
What step did Stella miss in her explanation?

(1 point)
Responses

tRNA delivers the DNA to the ribosome.
tRNA delivers the DNA to the ribosome.

DNA is replicated into two daughter cells.
DNA is replicated into two daughter cells.

Polypeptide chains express gene traits.
Polypeptide chains express gene traits.

mRNA is translated into amino acids.

Answer 9

The step that Stella missed in her explanation is:

mRNA is translated into amino acids.

This is a critical step in protein synthesis where the mRNA sequence (created from the DNA during transcription) is read by the ribosome, and tRNA brings the appropriate amino acids to form the polypeptide chain.