Transcript Intro to Genetics

Introduction to Genetics
Chromosomes
• Chromosomes are made up of DNA
wrapped around proteins.
• Each chromosome codes for several
genes.
• Each Gene codes for a protein.
Human genetics
• Each healthy person has 23 pairs of
chromosomes. (46 total = Diploid 2n)
• Each Pair codes for the same genes and
are called Homologous Chromosomes
• You got 23 from your mom and 23 from
your dad.
Sperm and Egg are Haploid
• Sperm and eggs are haploid cells known
as gametes
• Each Sperm has 23 Chromosomes
• Each Egg has 23 Chromosomes.
• 2 Gametes come together to form a
zygote
Homologous Chromosomes
• Homologous Chromosomes code for the
same genes
• Different version of the same Gene are
called alleles and will produce different
proteins that may function differently.
• Some alleles are dominant (will be
expressed no matter what)
• Some alleles are recessive (will only be
expressed if you have two copies.)
Hypothetical Example
Dad is Homozygous
Mom is Heterozygous
• Visit a map of the Human Genome
http://www.ncbi.nlm.nih.gov/science96/chr.c
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