Chapter 12 - Human Genetics Flashcards
12.1
Steps of DNA packing?
- DNA wraps tightly around histones
- DNA and histones form a tight coil
- coil twists into a Super Coil
12.1
Genome?
Where is the DNA found?
an organisms complete set of DNA
found in the chromosomes of the nucleus
12.1
histones?
small proteins involved in DNA packing
12.1
What is the importance of the Human Genome Project?
provides a rough draft of human genome’s full sequence
the info can :
- identify genes associated with disease
- develop treatment for genetic disorders
- identify relationships between species
12.2
What is Trisomy 21?
What is the result of Trisomy 21?
Trisomy 21 : a condition in which a person has three number 21 chromosomes.
results in : symptoms called Down Syndrome
12.2
Errors in the number of chromosomes usually happen because of ________.
nondisjunction :
a pair of homologous chromosomes (sister chromatids) fail to desperate, which produces a gamete with two copies of the chromosome.
12.2
Four types of changes that cause damage to chromosomes?
- deletion
- inversion
- duplication
- translocation
12.2
Describe duplication?
occurs when part of a chromosome is REPEATED.
12.2
Describe deletion?
occurs when part of a chromosome is LOST
12.2
Describe inversion?
occurs when a part of a chromosome is REVERSED.
12.2
Describe translocation?
occurs when a portion of a chromosome attaches to a non homologous chromosome
12.2
What are transposons?
“jumping genes”
genes that jump, changing their location on the same chromosome or moving to another chromosome entirely, disrupting the function.
12.3
Pedigree?
a diagram used by scientists that traces the occurrence of a trait in a family.
12.3
Carrier?
an individual with one copy of the recessive allele (a disorder) that does not show symptoms
ex : Ff
12.3
sex linked disorders?
allele located on a sex chromosome
ex : color blindness is found on X chromosome, so male (XY) who inherits one allele for the trait will be color blind but female (XX) needs two.
