IVE - DNA Flashcards
DNA is a _____ (in reference to its structure)
polymer i.e. it is made up of smaller, joined together molecules called monomers
What are the monomers in DNA called?
nucleotides
small section of DNA?
chromosome
small segment of chromosome?
gene
a gene codes for a sequence of ________ ________
amino acids - form proteins
DNA determines which type of _________ the cell it is in codes for, thus which types of cell it will be
protein - since the DNA is built of chromosomes, and genes, and each gene codes for a sequence of amino acids which form proteins
Genome definition
entire set of genetic material in an organism
Why was the discovery and construction of the human genome important
allows researchers to identify patterns in patients genes and predict the cause of inherited diseases.
Also beneficial for understanding the human evolutionary process and human migration journeys
Which pair of chromosomes is the sex chromosomes?
23rd -
xx = female
xy = male
DNA consists of two strands wrapped around each other known as the
double helix
Every nucleotide has exactly the same _________ and _____ and a different ____- of the four
phosphate, sugar and base
What is the structural framework of the DNA, the spine known as and why
phosphate sugar backbone
Each phosphate connects to a sugar and this repeats thousands of times in a single strand of DNA - this provides an outer casing for the bases
The bases attach to each other across the
two strands - the double helix structure - and this is what holds the double helix together.
Main uses of proteins
ENZYMES - biological catalyst
HORMONES
STRUCTURAL PROTEINS e.g. muscles
How many types of Bases?
4 - therefore there are four different types of nucleotides in the DNA
What are the four bases and which are complimentary?
Adenine
Thymine
Cytosine
Guanine
A-T
C-G
We call this concept complimentary base pairing and it allows us to figure out what the complimentary sequence of a given strand of DNA would be
A gene (in terms of bases)
a particular sequence of bases coded for a protein - a triplet of bases
A triplet code (bases)
codes for a specific amino acid - a protein is made of a sequence of amino acids
Gene =
segment of DNA that codes for a particular amino acid
Allele =
different versions of a gene
because we have two copies of every gene, one from each parent, we have two alleles of each gene:
- can be the same allele - homozygous
- can be two different alleles - hererozygous
If an allele is dominant it is expressed in the phenotype as well as the genotypes
If an allele is recessive it is only expressed in the genotype and cannot be visually observed
Genotype -
entire collection of alleles we have
Phenotype -
the characteristics from genotype that are physically expressed
