Unit Test: Genetics and Heredity

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Terms in this set (...)

Heredity
The process in which characteristics or traits pass from parents to offspring
Where are genes found?
Nucleus of the cells
What carry traits?
Traits are carried in tiny structures called genes
What do genes do in your body?
Each cell in the human body contains about 25 - 35 thousand genes that carry information to help determine your traits
Your parents pass some of their characteristics on to you through genes
Trait
characteristics you inherit from your parents
Genes
carry information that helps make you who you are
made of DNA
a section in the DNA that controls a trait that an organism inherits
DNA
Genetic material that carries information about an organism passed from parent to offspring
Complete set of instructions necessary to make and maintain the human body
Blueprint of a human body
Why is DNA interesting?
nonliving molecule
6 feet of DNA in every cell
unique for every individual
controls all activities in the cell
Chromosomes
DNA wrapped around protein to form an X-Shaped structure
DNA is too long to fit into a nucleus neatly; it must be tightly wound-up to fit inside the cell
made up of genes
made of DNA
Where is DNA?
Found in cells..
inside the nucleus
Chromosomes are made of DNA
How many pairs of chromosomes are in each human cell?
Each human cell has 23 pairs of chromosomes
How important are chromosomes?
-Humans need all 46 chromosomes to survive
-Humans that are missing one of the 46 chromosomes will not survive
-Humans with more than two copies of a chromosome will not develop properly
-Downs syndrome is caused at the 21 pair of chromosomes if they have an extra one
Homozygous
when genes are identical; purebred
Heterozygous
when genes are different; hybrid
Genotype
the two genes that determine an organisms traits expressed as a 2 letter code (TT) (2 alleles)
Phenotype
The physical characteristics of an organism you can observe (Tall)
Dominant
the trait that will be expressed if present (TT//Tt) only uppercase
Recessive
it can only be expressed if dominant trait is not present. (tt) only lowercase
Gregor Mendel
"Father of Genetics"
based his study on garden pea plants
Law of Segregation:
Traits are handed down through gametes
genes come in pairs
gene pairs split when gametes are formed so they only have half of the gene pair
Law of Independent Assortment:
Genes contained in gametes are handed down at random so no two offspring will be the same
Punnett Square
a tool used to show the possible genotypes of offspring
Genetic Variation
differences in DNA/Genes that can be external features or behaviors
Genetic Mutation
any alteration/change to the intended genetic structure or genotype