Powerpoint Chapter 8 Flashcards
segments of DNA that code for proteins
Genes
Single, circular chromosomes
Prokaryotes
Linear chromosomes
Eukaryotes
Human cells have _____ chromosomes.
46
Genetic Diversity: about ________ different combinations of chromosomes are possible.
8 million
Produces more diversity
Random fertilization
8 million x 8 million =
64 trillion possibilities
The first genetic scientist; accurately described simple rules of inheritance
Gregor Mendel
Controlled mating between pea plants
Gregor Mendel
Described patterns of inheritance for traits from single genes with a few alleles
Gregor Mendel
Mendelian principles also apply to many genetic diseases in humans.
Gregor Mendel
Physical traits of an individual
Phenotypes
Genetic composition of an individual; describes alleles
Genotype
homozygote carries two copies of the same allele
Homozygous
heterozygote carries two different alleles for a gene
Heterozygous
the phenotype of an allele is seen only when homozygous
Recessive
the phenotype is seen when homozygous or heterozygous
Dominant
a recessive genetic disease
Cystic Fibrosis
defect in chloride ion transport in the lungs
cystic fibrosis
produces thick mucus and lung deterioration
cystic fibrosis
dramatically shortened lifespans due to cystic fibrosis
true
Heterozygotes (carries) do not show the symptoms for cystic fibrosis.
True
Most common recessive disease among europeans
Cystic Fibrosis
A dominant human genetic disease
Huntington’s disease
Progressive and incurable
Huntington’s disease
Symptoms appear in middle age for Huntington’s disease
true
Nervous, mental, and muscular symptoms continue to worsen resulting in ______.
death
Mutant protein kills nerve cells by forming clumps inside the nuclei. (Huntington’s Disease)
True
having a normal allele does not compensate. (Huntington’s disease)
True
