gene
a length of DNA that codes for a protein
alleles
alternative versions of a gene. A section of DNA that codes for a particular protein
chromosomes
thread-like structures in which DNA is coiled and packed
what do genes and alleles provide?
variation in populations
What structure does DNA have?
Double helix structure
genetic code
the sequence of bases in a gene
What does the genetic code determine?
The order in which amino acids are joined together to make a specific protein
Where does protein synthesis occur?
In the ribosomes
messengerRNA (mRNA)
a type of genetic material that carries genetic information from the nucleus to ribosomes to make protein
stages in protein synthesis (4)
mitosis
type of nuclear division that gives rise to genetically identical cells
What is mitosis responsible for and involved in?
responsible for the repair of damaged tissues and the replacement of cells involved in asexual reproduction
What must occur before mitosis?
DNA duplication so that there is enough DNA for each new cell
Mitosis produces
diploid cells
Meiosis
type of nuclear division that gives rise to genetically different cells
Meiosis produces
haploid cells
what is meiosis involved in?
involved in the production of gametes
Meiosis is involved in what type of reproduction?
Sexual reproduction
In meiosis, the number of chromosomes is…
halved
In meiosis a diploid cell becomes
four haploid cells
homozygous
two identical alleles
heterozygous
two different alleles
phenotype
observable features of an organism
genotype
all the alleles present in that organism