The features of signal-transducing systems are A) amplification and specificity

Question

The features of signal-transducing systems are

A) amplification and specificity

B) desensitization/adaptation

C) integration and modularity

D) localized response

E) amplification, specificity, decensitization

Oncogenic mutations can result from DNA rearrangements or duplications. Consider the following scenario. Gene 1 encodes a protein that is always expressed at high levels. Gene 2 encodes a growth stimulating protein that is only expressed when the cell has received growth promoting signals. On occasion, Gene 2 gets positioned downstream of the promoter for Gene 1. What are the possible consequences?

A) There will be no consequences for Gene 2

B) Gene 2 will lose its responsivity to growth promoting signals and will express at high levels

C) Gene 1 will keep being expressed at high levels

D) A and C

E) BandC

Approximately what fraction of the human genome is transposable elements?

1.5%
5%
10%

45%

80%

A typical human epithelial cell in G2 of interphase would possess:

A) 23 replicated chromosomes
B) 46 unreplicated chromosomes
C) 96 unreplicated chromosomes

D) 23 unreplicated chromosomes E) 46 replicated chromosomes

Which statement is correct:
A. DNA replication is initiated at promoter sequences in the DNA
B. RNA polymerase requires primers to initiate RNA synthesis
C. Okazaki fragments are the short fragments of DNA that are produced on the leading strand at the DNA replication

fork.

D. Transcription is terminated at stop codons in the mRNA
E. The 5' to 3' direction of DNA synthesis implies that deoxyribonucleotides are added to the 3' OH group on the

growing strand.

The gene for the hemoglobin b subunit is 1,420 bp long and contains two introns that are 131 bp and 851 bp long. How long is the b-subunit polypeptide?

146 amino acids long

327 amino acids long

438 amino acids long

473 amino acids long

2,140 amino acids long

Explanation / Answer

Answer1:B-Desensitization/adaption

Receptor activation triggers a feedback circuit that shuts off the receptor or removes it from the surface.

Answer2:E-B and C.

Answer3:Although a large proportion (44%)of the human genome is occupied by transposons and transposon like repetitive elements ,only a small proportion of these elements remains active today.

Answer4:E-46 replicated chromosomes

At first the cells have the same number of chromosomes at mitosis.DNA replication occurs ,giving a total of 46 chromosomes.

Answer5:All the above are false statements

1.DNA replication is initiated at the origin of replication.RNA polymerases bind to pormoter sequences to initiate transcription.

2.RNA polymerase dose not require primers to initiate RNA synthesis.DNA polymerase required primers to initiate DNA replication.

3.Okazaki fragments are made on the lagging strand at the replication fork.

4.DNA synthesis occurs by addition of dNTP's to the 3'OH group of the nucleotide at the end of the growing strand.

5.Transcription terminates at the transcription termination sites in the DNA.Translation ends at stop codons in the mRNA.

Answer6:

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.