Lecture 10 Flashcards
DNA to genomes
What is the structure of DNA
DNA is a double helix with two sugar phosphate backbones. The sugar phosphate has a negative charge.
What is gene structure?
They are strings of nucleotides (A, C, T, G).
How do genes relate to DNA?
A gene is a section of DNA that carry instructions for specific proteins or RNA molecules. This information is expressed through transcription and translation. They are inherited through generations.
What is a chromosome?
A chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA). It is located in the nucleus. There are prokaryotic and eukaryotic chromosomes.
What is the structure of a eukaryotic chromosome?
Chromosomes consist of a DNA molecule packed together with proteins. The tips of the chromosome are capped together by sections of DNA called telomere. The centromere divides the chromosome into two sections, the long one called q arm, and the short one called p arm.
What is a haploid cell?
Contains one set of chromosomes.
What is a diploid cell?
Refers to the presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair.
Define gene
A distinct sequence of nucleotides forming part of a chromosome, the order of which determines the order of monomers in a polypeptide or nucleic acid molecule which a cell (or virus) may synthesize.
Define nucleosome
A nucleosome is a unit of DNA packaging in
eukaryotes, consisting of DNA wound around eight histone proteins.
Define Karyotype
Karyotype is the display of the chromosome pairs of a cell arranged by size and shape
Define genome
The complete set of an organism’s
genes and other DNA sequences.
How is DNA packaged into chromosomes?
Through a nucleosome structure which wraps the DNA around the structural histone proteins.
What are histone proteins?
Histones bind to DNA, help give chromosomes their shape, and help control the activity of genes.
What is chromatin?
The material that chromosomes of eukaryotic organism’s chromosomes are composed of, consisting of RNA & DNA.
Euchromatin VS Heterochromatin
Euchromatin is transcriptionally active, less condensed, and gene rich. Heterochromatin is transcriptionally inactive, gene poor, and highly condensed.
