DNA, Genes and Chromsomes Flashcards
What is a gene?
A gene is a section of DNA that contains coded information to form polypeptides and functional RNA
What is chromosome?
A chromosome is tightly coiled DNA, acts as DNA storage
What is the locus?
The locus is the location of where to find a particular gene
What two organelles in eukaryotic cells contain their own DNA?
The mitochondria and chloroplasts
How many chromosomes are in the human body?
There are 46 individual chromosomes, in 23 pairs
What are homologous pairs?
Homologous pairs are chromosomes that have identical genes, but may have different alleles
What is an allele?
A different form of a gene
What is the 23rd pair of chromosomes?
The 23rd pair of chromosomes is the sex chromosomes (X and Y), therefore it is never numbered
How is DNA stored in eukaryotic cells?
DNA is stored in the nucleus. The DNA is tightly wound around histone proteins. This forms nucleosomes
How is DNA stored in prokaryotic cells?
DNA molecules are shorter and circular so they are not protein bound, instead they supercoil to fit inside the cell
How is DNA in chloroplasts and mitochondria similar to prokaryotic cells?
DNA in chloroplasts and mitochondria are short and circular like prokaryotic cells. They are also not protein bound like prokaryotic cells
What is the function of a histone protein?
A histone protein assists in the tight coiling of DNA to fit chromosomes into the nucleus
What shape are chromosomes in eukaryotic cells compared to the shape of chromosomes in prokaryotic cells?
Chromosomes are linear in shape in eukaryotic cells compared to prokaryotic cells short and circular shape
Describe the DNA found in prokaryotic cells, mitochondria and chloroplasts
DNA is short and circular and is not protein bound (not wound around histones)
