Unit 3 - DNA review Flashcards
DNA
- DNA is the primary carrier of genetic info
- DNA is responsible for ensuring the genetic continuity of species, and community of life
DNA and Chromsomes
- DNA is passed from generation to generation in form of of chromosome
- specific to each species
Chromosomes in species
1) humans = 46
2) turkeys = 82
3) fruit flies = 8
4) starfish = 36
5) potatoes = 48
Genes
genes r the coding regions of DAN which contain the instructions for building the protein that r responsible for each inherited trait
(nitrogenous bases in the DNA sequence that code for a particular trait)
DNA packing
an enormous amt of information is stored in an organim’s DNA and it must fit inside every cell in the organism
ie. eukaryote and prokayotes handle this packing problem in diff ways
In Eukaryotes 1st level =
DNA wraps around histones to form a nucleosome
In Eukaryotes 2nd level =
the nucleosomes wrap around one another to from a chromatin fiber
In Eukaryotes 3rd level =
the fibres create loops w the help of scaffold proteins to further compact the structure
In Eukaryotes 4th level =
the scaffold will fold into a more compact structure ie. chromosome
Histone
a special protein mol that is a core around which DNA strand wrpas
in Prokaryotes
organisms r less complex they contain less genetic material
- bacterial chromosomes r usully found in loops. The bacterial DNA is joined end to end to form one large ring w additional smaller loops of Dna called plasmids
Plasmid
small circular section of DNA found in the cytosol of bacteria; replicates independently of the chromosmal DNA
Archaea
circular chromosomes but like E, there DNA is associated with histone-like proteins
Nuclesome
section of DNA wrapped around histones
Chromatin
DNA structural proteins
