7A. Genes and Chromosomes Flashcards
DNA nucleotide/monomer has…
phosphate group.
deoxyribose sugar
nitrogenous base
Monomers are joined through hydrogen bonds between what
A=T or G=C
Genome
haploid set of chromosomes within an organism, including all genes.
Gene
a section of DNA that carries a code to make protein.
Gene loci
genes that are found at specific locations on chromosomes
Allele
alternative form of the same gene
Everyone has two copies of each gene
one inherited from mother and the father
Humans have how many genes in each cell that make up genome.
25,000
Of the 25,000 genes, only about what percent are responsible for making us all unique.
1%
Of 23 chromosome pairs how many are autosomal and sex
Autosomal= 22
Sex= 1
Telomere
a region of repetitive base sequences, found at the end of every chromosome.
Describe a DNA molecule
each chromosome is composed of a long DNA molecule that has been coiled tightly around histone proteins. A double helix structure.
Centromere
a specialised sequence of DNA that holds together the two chromatids.
Sister chromatids
identical daughter strands of a replicated chromosome
Sister chromatids
identical daughter strands of a replicated chromosome
Aneuploidy
when an organism has an abnormal and incorrect number of chromosomes.
Monosomy
One missing chromosome
Trisomy
One extra chromosome
Tetrasomy
Two extra chromosomes
Polyploidy
A triploid genome rather than diploid
Karyotypes are used to
visualise chromosomes
Homologous chromosomes
Are the same size and length
Have the same centromere location
The same genes at the same loci
homologous chromosomes are…
are a pair of chromosomes with one inherited from the mother and second from the father.
