The Nature of Genes Flashcards
(49 cards)
What are chromosomes?
DNA molecules found inside of cells packaged in long strands
What is DNA?
A long molecule made of building blocks called nucleotides
What is each nucleotide made out of?
Nitrogen containing base
Deoxyribose sugar
Phosphate
What is the shape of DNA?
Anti-parallel double helix
What are the four different nitrogenous bases?
Adenine, Thymine, Cytosine, Guanine
What are the nitrogen base pairs?
AT
CG
What are triplets/codons?
A sequence of three nucleotide bases that code for one amino acid
What are alleles?
Variations of the same gene
Why are alleles different?
Different base sequencing
Which allele is expressed?
The dominant one
What is a nucleosome?
DNA wrapped around a histone (proteins)
What is a gene?
Specific segment of DNA that has information about a specific part of how the organism should work. They ‘code for a specific protein molecule’
What are the two arms of a chromosome?
P and Q
What is the name for the longer arm of the chromosome?
Q arm
What is the name for the shorter arm of the chromosome?
P arm
What do chromosome classifications depend on?
Shape
Size
Position of centromere
Sex determining or not
Gene position
What is a telocentric chromosome?
Barely/no p arm
What is an arocentric chromosome?
Small amounts of p arm
What is a submetacentric chromosome?
Almost equal p and q arm length
What is a metacentric chromosome?
Equal p and q arm
What is a locus?
A gene’s unique position
What is a spacer?
Region between genes that doesn’t code for anything
What does ploidy mean?
The amount of chromosomes set a cell carries
How many chromosomes does a human somatic cell have?
46
