Transcript Modern Genetics - Hicksville Public Schools / Homepage

Human Inheritance- Important Facts
1) Sex chromosomes carry genes that determine
whether a person is male or female.
Girls have XX
Boys have XY
2) Sex Linked genes- alleles are passed from
parent to child on a sex chromosome. (Ex.
Color blindness)
3) Carrier- Person who does not show a trait but
can pass it on to their offspring. (They are
hybrids for that trait)
A person’s characteristics are determined by
an interaction between genes and the
environment.
Human Genetic Disorders
Some genetic disorders are caused by mutations
in the DNA of genes. Other disorders are
caused by changes in the structure or number
or chromosomes.
Cystic Fibrosis- Body produces too much
mucus in the lungs and the intestines, which
makes it hard for a person to breath.
Sickle Cell Disease
Affects Hemoglobin, the
protein in the blood that
carries oxygen. The red
blood cell has a sickle
shape, cannot carry as
much oxygen and clogs
blood vessels.
Hemophilia
Person’s blood clots
very slowly or not
at all. There is a
high danger of
internal bleeding.
Down Syndrome
A person’s cells have an extra copy of chromosome 21.
People have some degree of mental retardation and
heart defects are common.
Pedigree Chart- Family tree that tracks
which family members have a particular
trait.
1. How many children did the original parents have?
____________
2. What is the total number of children and grandchildren who
are color-blind in this family?
___________________________________________________
__________________________________________________
Branching Tree- shows how different
organisms are related.
Darwin’s Theory
Darwin’s Observations
• Diversity- He observed a variety of living things
• Fossils- He observed fossils of animals that were no
longer alive.
• Galapagos Organisms- He observed that organisms
in the Galapagos resembled those from mainland,
but there were significant differences.
Vocabulary
• Adaptation- Trait that helps an organism
survive and reproduce. Examples: beak
shape for birds, a plant that tastes bad or is
poisonous.
• Evolution- Gradual change of a species over
time.
• Natural Selection- Process by which
individuals that are better adapted to their
environment are more likely to survive and
reproduce. Over time, natural selection may
lead to change. Helpful variations may
accumulate while unfavorable ones may
disappear.
• Variation- Any difference between the
organisms of the same species.
• Competition- Organism compete with
each other for food, mates and other
resources.
• Environmental change- A change in the
environment can affect an organism's
ability to survive which may lead to
natural selection.
Evidence of Evolution
• Fossils
• Patterns of early development
• Similar body structures
Advances in Genetics
• Clone- organism that is genetically identical to
the organism from which it was produced.
• Human Genome Project- Has the purpose to
identify the DNA sequence of every gene in the
human genome.
• Selective Breeding- Process of selecting a few
organisms with desired traits to serve as parents
for the next generation.