LECTURE 6 - STUDY GUIDE

Question 1

105. How is the gene structure different for prokaryotic and eukaryotic DNA (and in general pre-mRNA created during transcription)?

Answer 1

Eukaryotes have a bit larger ribosome compared to prokaryotes.
You are sending the mRNA from the nucleus from the cytoplasm to the ribosome so you need protection
prokaryotes: location where translation is happening-the ribosome is right next to it so transportation (no protection)

Question 2

106. In eukaryotic organisms, the genes are interrupted by sequences that are not represented in the mRNA protein (not everything is a blueprint with the DNA). The noncoding DNA that interrupts the sequence of the gene is called the _____ and _____ are the coding sequences. Fill in the blanks.

Answer 2

1. intron
2. exon

Question 3

107. Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression. What is RNA splicing?

Answer 3

Splicing-remove introns

Question 4

108. Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression. Where does RNA splicing occur within a cell?

Answer 4

Takes place in the nucleus before you send it out to the cytoplasm and then the ribosome

Question 5

109. Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression. What is the function of snRNPs involved in this process?

Answer 5

snRNPs-the things responsible for moving the introns

(make a lariat shape with your intron and then removed it)

Question 6

110. Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression and near the end of the process, a spliceosome begins to form. What is a spliceosome?

Answer 6

Spliceosome - made of the snRNPs, when you have that lariat shape.

Question 7

111. Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression. Which statement does not describe the steps of this process of RNA splicing?

Question 8

112. Regarding eukaryotic genes, what is the rule for the number and size of the introns and exons per gene?

Answer 8

There are no rules. Trick Question.

Question 9

113. Regarding eukaryotic genes, why does RNA splicing occur in the first place?

Question 10

114. Regarding eukaryotic genes, what is alternative splicing?

Answer 10

Single primary transcript can sometimes be spliced into different mRNAs by the inclusion of different sets of exons

Question 11

115. Know what is occurring during each step of this overview of transcription and translation if this question is chosen. (look at the picture on chapter fifteen slide thirty-one)

Question 12

116. Which statement does not describes a difference between prokaryotic and eukaryotic gene expression? (know the information we discussed on chapter fifteen slide thirty-two)

Answer 12

Often are going to contains several transcripts of several genes (very long mRNA) (unsure)

Question 13

117. Genes can be altered by random mutations or external factors. Which statement accurately describes (a) a base substitution or (b) chemical modification?

Answer 13

Base substitution- Spontaneous pairing errors during DNA replication.
Chemical modification- ????

Question 14

118. Genes can be altered by random mutations or external factors. Which statement accurately describes (a) DNA breaks, (b) frameshift mutations, or (c) triplet expansion?

Answer 14

DNA breaks: Ionizing radiation can cause double strand breaks in DNA (loss of short segments)

Triplet expansion: Adds additional copies of repeated 3-base sequence
Frameshift mutation: short deletion near the start, end, or middle of a codon.

Question 15

119. Why is it that some genes cannot be transcribed? (we discussed the answer on the very last slide of chapter fifteen)

Question 16

120. Mutations can arise from changes in gene positions. Which statement accurately describe (a) translocation, (b) inversions, or (c) duplication errors?

Answer 16

Translocation: Segment of one chromosome becomes part of another chromosome
Inversions: The orientation of a portion of a chromosome is reversed
Duplication: Duplicating a certain portion of it

Question 17

121. Mutations can arise from changes in gene positions. Which statement accurately describe (a) insertions or (b) deletions?

Answer 17

Insertions: When you’re inserting a bunch of information that weren’t there prior
Deletions: Deleting parts of a chromosome

Question 18

122. Regarding chromosomes, what is the difference between aneuploidy and polyploidy?

Answer 18

Aneuploidy: Lose or you gain a chromosome

Polyploidy: Add entire sets of chromosomes.