Mastering Bio Ch. 6 - DNA

Consider the amino acid sequence methionine-valine-phenylalanine. How many different genetic codes would produce this amino acid sequence? https://session.masteringbiology.com/problemAsset/1822899/1/ch6_q7img.jpg A. 1 B. 2 C. 4 D. 8

D. 8 There is only one genetic code for methionine. However, there are four different codes that specify valine and two different codes that specify phenylalanine. Thus, the answer to this question is 1 × 4 × 2 = 8.

During translation, the message in mRNA is translated into a protein. Can you identify the structures and molecules involved in translation? Small subunit of ribosome Anticodon tRNA Large subunit of ribosome Amino Acid mRNA

mRNA sits on the SMALL subunit of ribosome tRNA sits on the LARGE subunit of ribosome Anticodon connects the mRNA and tRNA Amino acids are attached to the top of the tRNA

During transcription of a specific gene, only one DNA strand serves as a template for the formation of RNA. A. True B. False

A. True RNA polymerase binds to a specific DNA sequence on the template strand to initiate transcription. The other strand is not transcribed.

Can you match each term related to the genetic basis of cancer with its description? 1. A normal gene that, if mutated, can lead to cancer is called a(n) ____________. 2. A gene that causes a cell to become cancerous is called a(n) ____________. 3. A(n) ____________ is a gene that encodes proteins that inhibit cell division. Such proteins normally help prevent cells from becoming cancerous. 4. A(n) ____________ is a protein that promotes cell division. In excess, such a protein may lead to cancer. tumor-suppressor gene proto-oncogene carcinogen oncogene growth factor

1. A normal gene that, if mutated, can lead to cancer is called a(n) PROTO-ONCOGENE. 2. A gene that causes a cell to become cancerous is called a(n) ONCOGENE. 3. A(n) TUMOR-SUPPRESSOR GENE is a gene that encodes proteins that inhibit cell division. Such proteins normally help prevent cells from becoming cancerous. 4. A(n) GROWTH FACTOR is a protein that promotes cell division. In excess, such a protein may lead to cancer.

During DNA replication, __________. A. each of the two daughter DNA molecules contains one strand from the original DNA molecule and one newly synthesized strand B. a new daughter DNA molecule contains two newly synthesized strands that are identical copies of the original DNA molecule C. only one of the strands of the parent DNA molecule serves as a template for DNA replication D. the original DNA molecule is destroyed

A. each of the two daughter DNA molecules contains one strand from the original DNA molecule and one newly synthesized strand People describe DNA replication as semi-conservative because each daughter molecule contains one of the strands from the parent molecule and one newly synthesized strand.

Which part of a nucleotide molecule encodes genetic information? A. the base B. hydrogen bonds C. the sugar D. the double helix

A. the base Genetic information is encoded in the four-letter alphabet that corresponds to the four bases: adenine, guanine, cytosine, and thymine.

If we wanted to join a nucleotide to another to form a polynucleotide, the sugar of the first would bind to which part of the second nucleotide? (Part B) A. sugar B. phosphate C. polyphosphate D. deoxyribose E. base

B. phosphate

Which of the following mutations is LEAST likely to result in harmful changes to cells? A. nonsense mutations B. silent mutation C. missense mutation D. frameshift mutations

B. silent mutation

A polynucleotide has the sequence GCAC running along one strand. What must be the sequence of the other strand? (Part C) A. ATCG B. CACG C. CGTG D. GCAC E. GTGC

C. CGTG

DNA and RNA have three important structural differences. These include all of the following EXCEPT that __________. A. in living cells, DNA is usually a double-stranded molecule while RNA can often be single-stranded B. DNA contains deoxyribose while RNA contains the sugar ribose C. DNA contains phosphate while RNA does not D. DNA contains the bases A, G, C, and T while RNA contains the bases A, G, C, and U

C. DNA contains phosphate while RNA does not Both DNA and RNA contain phosphate groups.

In what way might you expect transcription and translation to be different in prokaryotic cells compared to eukaryotic cells? A. Transcription is not necessary in prokaryotic cells. Genetic information can be directly translated from DNA. B. Transcription follows different base pairing rules in prokaryotic cells. C. In prokaryotic cells, translation can occur before transcription. D. In prokaryotes, transcription and translation can take place at the same place and same time.

D. In prokaryotes, transcription and translation can take place at the same place and same time. Because prokaryotes lack a nucleus, transcription occurs in the cytoplasm. Translation can begin while mRNA is still being transcribed.

This model is of one particular kind of nucleotide. If I had another model of a different kind of nucleotide, which parts would be identical between the two? A. base only B. sugar, phosphate, and base C. sugar only D. sugar and phosphate only E. phosphate only

D. sugar and phosphate only The sugar and phosphate groups are the same for all DNA nucleotides. The base is the one part that changes.

If we wanted to be complete, how many different models would we need to show all the kinds of nucleotides? (Part D) A. 3 B. 16 C. 2 D. 8 E. 4

E. 4 There are four kinds of DNA nucleotides, abbreviated A, T, C, and G.

What color is deoxyribose? (Part A) A. green B. white C. black D. yellow E. blue

E. blue (in the middle)

Can you complete this paragraph about the cellular processes involved in protein production? The cellular processes that results in the production of protein begin in the _______________, where the DNA resides. There, the process of _______________ creates a molecule of RNA from a molecule of DNA. The enzyme that performs this process is called _______________. The RNA molecule, which exits the nucleus, is a specific kind of RNA called _______________. Once it exits the nucleus via the nuclear pores, this molecule travels to a cellular organelle called the _______________. There, the sequence of nucleotides on this molecule is used to create a molecule of protein through the process called _______________. This process is helped along by molecules of _______________, each of which recognizes one nucleotide triplet and carries the corresponding amino acid. tRNA nucleus RNA polymerase translation mRNA ribosome transcription

The cellular processes that results in the production of protein begin in the NUCLEUS, where the DNA resides. There, the process of TRANSCRIPTION creates a molecule of RNA from a molecule of DNA. The enzyme that performs this process is called RNA POLYMERASE. The RNA molecule, which exits the nucleus, is a specific kind of RNA called mRNA. Once it exits the nucleus via the nuclear pores, this molecule travels to a cellular organelle called the RIBOSOME. There, the sequence of nucleotides on this molecule is used to create a molecule of protein through the process called TRANSLATION. This process is helped along by molecules of tRNA, each of which recognizes one nucleotide triplet and carries the corresponding amino acid.

During transcription, an RNA molecule (shown in red) is transcribed from DNA (shown in blue). Can you label the bases on the RNA transcript? A U T C G

UCGA A matches with U. C matches G. T is not used because it is an RNA molecule, and T is only used in DNA.