Genetic information, variation and relationships between organisms Flashcards
(87 cards)
What are the differences between prokaryotes and eukaryotes?
Prokaryotes are smaller
Prokaryotes have no Nucleus and instead have circular DNA rather than linear
prokaryotes have smaller ribosomes
Prokaryotes have marine walls however eukaryotes have chitin or Celulose
What are the features of DNA in prokaryotes?
Short, circular, not associated with proteins
What are the features of DNA in a eukaryote?
inside a nucleus, associated with proteins(histones), long and linear
What is an intron?
non-coding DNA within a gene
What are exons?
Coding regions of DNA
What type of DNA do prokaryotes not have?
introns
Why is the DNA of mitochondria and chloroplasts similar to that of prokaryotes?
Because it is short, circular and not associated with proteins
If a gene contains 240 bases, what is the maximum number of amino acids this gene code for?
80, (240➗3) this is because bases are read in triplets
Smallest to largest: gene, exon, base, nucleotide, chromosone, cell, nucleus
base, nucleotide, Exon, gene, chromosome, nucleus, cell
What is a gene?
A section of DNA that codes for a single specific protein
What is DNA?
The double-stranded polynucleotide from which genes are made
What is a chromosome?
Thread like structure made of DNA and associated proteins
What are histones?
proteins that associate with eukaryotic DNA to from chromosomes
Where are genes found?
On chromosomes
What are homologous chromosomes?
chromosomes that are the same size and have the same genes. (Although they may carry different alleles).
What is the fix position of a gene on a chromosome called?
the gene locus
What is an allele?
Any of two or more variants of a gene
What is a triplet?
The three bases each amino acid is coded for by
The genetic code is degenerate, what does this mean?
there are 64 triplets, but only 20 amino acids. Few amino acids have only a single triplet. There is more than one base triplet for each amino acid to be coded for by.
The genetic code is universal. What does this mean?
The same triplet codes for the same amino acid in all organisms
what is functional RNA?
any RNA (except mRNA) that perform special tasks during protein synthesis, e.g. tRNA. Some genes code for functional RNA, and not proteins.
What does mRNA do?
Copies messages from DNA for protein synthesis
what does mRNA move through to get to the ribosome after leaving the nucleus?
Cytoplasm
What are the two parts of protein synthesis?
Transcription and translation