LECTURE 6 Flashcards
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.
Intron and Exon
Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression. What is RNA splicing?
RNA splicing removes the introns and joins the exons together.
Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression. Where does RNA splicing occur within a cell?
Nucleus
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?
They remove introns and form on both sides
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?
It is responsible for intron and exon splicing in eukaryotes
Regarding eukaryotic genes, what is the rule for the number and size of the introns and exons per gene?
There is no number for the size
Regarding eukaryotic genes, what is alternative splicing?
Single primary transcript can be spliced into different mRNAs by the inclusions of different sets of exons.
Genes can be altered by random mutations or external factors. Which statement accurately describes (a) a base substitution or (b) chemical modification?
Base substitution is spontaneous pairing errors during DNA replication. Chemical modification is a base may be chemically altered by a mutagenic chemical
Genes can be altered by random mutations or external factors. Which statement accurately describes (a) DNA breaks, (b) frameshift mutations, or (c) triplet expansion?
DNA breaks: ionizing radiation can cause double-strand breaks in DNA loss of short segments Frameshift mutations: short detection near the start, end or middle of a codon. Triple expansion: adds additional copies of three bases sequences (good or bad)
Mutations can arise from changes in gene positions. Which statement accurately describes (a) translocation, (b) inversions, or (c) duplication errors?
Translocation: segment of one chromosome becomes part of another chromosome. Inversions: the orientation of abortion of a chromosome. Duplication errors: error or damage while duplication
Mutations can arise from changes in gene positions. Which statement accurately describes (a) insertions or (b) deletions?
Insertions add a segment. Deletions take away a DNA segment.
Regarding chromosomes, what is the difference between aneuploidy and polyploidy?
Aneuploidy - losing or gaining chromosome
Polyploidy - Complete new set of chromosomes
