Genetic Information, Variation and Relationships between Organisms Flashcards
Describe DNA in a prokaryotic cell
-short
-circular
-not associated with proteins
Describe DNA in a eukaryotic cell.
-long
-linear
-associated with proteins called histones
What forms a chromosome?
A DNA molecules and its associated proteins
What is the fixed position that a gene occupies on a DNA molecule called?
A locus
What is a sequence of 3 DNA bases called?
A triplet
What does a triplet code for?
A specific amino acid
What are amino acid coding sequences called?
Exons
What are non coding sequences called?
Introns
What is splicing (transcription)?
Introns from premRNA are removed and exons are joined together
mRNA leaves the nucleus to the ribosome
What type of DNA is found in matrixes in chloroplasts and mitochondria?
Like prokaryotic, short circular and not associated with proteins
What is the genome?
The Complete set of genes in the cell
What is the proteome?
The full range of proteins that a cell is able to produce
What are the 5 types of chromosome mutations?
Deletion, duplication, inversion, non-disjunction, translocation
Describe chromosomal deletion mutations
A portion of the chromosome is lost
Describe duplication chromosomal mutations
A segment of the chromosome is copied
Describe inversion chromosome mutations
A segment of the chromosome is reversed
Describe translocation mutations
A segment of one chromosome is transferred to another
Describe non disjunction mutations
Chromosomes fail to separate properly during meiosis leading to an abnormal number of chromosomes
What is genetic variation?
The difference in base sequences between two or more organisms, resulting in different alleles
What are homologous chromosomes?
One maternal and one paternal chromosome that carry genes at the same loci
What is independent segregation?
The process by which maternal and paternal copies of homologous chromosomes are allocated to different gametes
What can a gene code for?
The amino acid sequence of a polypeptide or functional RNA
Explain the statement “the genetic code is universal”.
The same four bases code for the same amino acids in all living organisms
Explain the statement “the genetic code is degenerate ”.
Multiple codons can code for the same amino acid
Explain the statement “the genetic code is non overlapping”
Each individual base is read once and is a part of only one triplet
