genetics 101 welcome to everything you wanted to know about genetics!
TRANSCRIPT
Genetics 101Welcome to everything you wanted to know about Genetics!
Genetics… is the study of genes, heredity, and
variation among living organisms. It is studied through biology.
Remember… Traits vary in a population…this is
the key to species survival!
Offspring resemble their parents and this is from the passing of genetic information.
Inheritance Passing genetic information from
one generation to the next. Offspring inherit alleles from their parents.
Gregor Mendel Conducted pioneering work with inheritance.
Most important work was done with pea plants…he studied the trait of flower color.
He realized that plants did not combine colors (i.e. purple + white did not give a pale lavender color, but the plant was either white or purple). Why?
The answer…genes!
Animal Cell Every living thing is made of cells. Cells have organelles and one organelle
is the nucleus (center part of a cell). Inside the nucleus is DNA. DNA = an inheritance messenger; a
huge molecule containing millions of atoms; DNA is coiled into chromosomes in the nucleus
Chromosomes = structures that carry the message of inheritance
Alleles allele = specific active location on a
chromosome
Genes Gene = two alleles on the paired
chromosome working together; a pair of alleles!
Big Ideas! 1. Nuclei contain chromosomes. 2. Chromosomes come in almost
identical pairs. 3. Chromosomes have specific active
locations called alleles. 4. The two alleles in identical locations
on paired chromosomes constitute a gene.
5. A gene (two alleles working together) controls a trait.
Genotype Genotype = combination of alleles
in an organism’s chromosomes
AA, Aa, or aa, are all genotypes.
Phenotype Phenotype = what trait is
expressed in an organism
It’s what they look like!
The traits that the genotype produce is the organism’s phenotype!
Dominant Dominant Alleles = more influential
alleles; represented by an uppercase letter
AA or Aa
Recessive Recessive Alleles = less influential
alleles; represented by a lowercase letter
Aa or aa
Examples: blonde or red hair, blue or green eyes
Reading Assignment! With another person at your table
group, you will: Partner read pages 46 through 55. Under each green heading, you will
write down 2-3 things you learned in your Science Notebook!
From Genotype to Phenotype! Decode the genotype to produce
the Larkey’s phenotype!