Biology Final- Genetics Flashcards
What is transcription?
When DNA is copied into the form of RNA
Where does transcription take place?
The process begins at a section of DNA called a promoter
What is a codon?
It consists of 3 consecutive nucleotides on mRNA that specify a particular amino acid
What are introns?
The DNA within a gene that is not needed to produce a protein
What is the DNA within a gene not needed to produce a protein called?
Introns
What is an extron?
The DNA sequences that code for proteins are called exons
What is an autosome?
Any chromosome that isn’t a sex chromsome
What is a chromosome that isn’t a sex chromosome called?
An autosome
What is a sex chromosome?
One of the two chromosomes that determine an individual’s sex (XX,XY)
What are mutations?
Changes in the genetic material of an organism
What are changes in the genetic material of an organism called?
Mutations
What are point mutations?
Gene mutations involving changes in one or a few nucleotides (they only occur at a single point in the DNA sequence).
Gene mutations involving changes in one or a few nucleotides are called what?
Point mutations
What are some different types of point mutations?
Substitutions, insertions, and deletions
What are frameshift mutations?
Mutations that shift the “reading frame” of the genetic message. This happens when a nucleotide is added or deleted, and the bases are still read in groups of three, but now those groupings are shifted for every codon that follows. By shifting the reading frame, frameshift mutations may change every amino acid that follows the point of that mutation Frameshift mutations can alter a protein so much that it’s unable to perform its normal functions.
What is it called when a nucleotide is added or deleted, and the bases are still read in groups of three, but now those groupings are shifted for every codon that follows?
Frameshift mutations
What are chromosomal mutations?
Changes in the number or structure of chromosomes. Such mutations may change the locations of genes on chromosomes, and may even change the number of copies of some genes.
What are changes in the number or structure of chromosomes?
Chromosomal mutations
What are the types of chromosomal mutations?
Deletion, Duplication, Inversion, and Translocation
What is incomplete dominance? Give an example
When one allele isn’t completely dominant over another (ex: red flower + white flower = pink flower)
What is codominance? Give an example
When both alleles contribute to the phenotype. (ex: chickens with both white and black feathers)
What are multiple alleles? Give an example
When a gene has more than 2 alleles (ex: rabbits + fur color)
What are polygenic traits? Give an example
Traits that are produced by the interaction of several genes. (ex: human skin color)
What does mRNA do?
Messenger RNA (mRNA) carries copies of instructions for assembling amino acids into proteins
What are ribosomes made up of?
Ribosomes are made up of proteins and ribosomal RNA (rRNA)
What does tRNA do?
During protein construction, transfer RNA (tRNA) transfers each amino acid to the ribosome.
