Human blood type exhibits which two types of non-Mendelian traits?
Co-dominance or incomplete dominance
What is true breeding?
A true-breeding organism is an organism that always passes down certain traits multiple generations in a row.
What's the difference between incomplete dominance and codominance?
In codominance, both alleles in the genotype are seen in the phenotype. In incomplete dominance, a mixture of the alleles in the genotype is seen in phenotype
Can a man be a carrier of a non sex-linked trait?
Yes, males can carry non-sex linked traits.
What is the name of the disease Lorenzo had in the movie?
Lorenzo had Adrenoleukodystrophy (ALD), a genetic disease that progressively destroys the brains of young boys
Who is the "father" of genetics?
Gregor Mendel
Can a man be a carrier of a sex-linked gene?
Only females can be carriers; males cannot be heterozygous carriers.
What pattern of inheritance does the disease (Lorenzo had) show?
X-linked (Sex-linked) inheritance
What is a carrier for a gene?
A carrier is someone who carries a recessive gene for a trait/disease, but does not express that trait (or have that disease)
What's the difference between homozygous and heterozygous?
Homozygous alleles look the same, while heterozygous alleles are different
What are the three different alleles exhibited in human blood type?
There are three different alleles, known as IA, IB, and i.
Why are Sex-linked recessive disorders more common in males?
Men only have one X chromosome
What's the difference between a gene & an allele?
A gene is a portion of DNA that determines a certain trait. An allele is a specific form of a gene.
What happens to the myelin around the nerve cells of ALD boys? What causes this change to occur?
buildup of very long chain fatty acids (VLCFAs) in the brain that destroy the protective myelin sheath around nerve cells.
What's the difference between genotype and phenotype?
Genotype is what the person's DNA looks like, while phenotype is how the genes are expressed physically (example: blonde hair)
What is a testcross?
experimental cross of an individual organism of dominant phenotype but unknown genotype and an organism with a homozygous recessive genotype
What is a sex-linked gene?
Sex-linked, as related to genetics, refers to characteristics (or traits) that are influenced by genes carried on the sex chromosomes
What is Mendel's Law of Dominance?
Mendel's law of dominance states that in a heterozygote, one trait will hide the presence of another trait for the same characteristic
What is myelin?
Myelin is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord
What is a polygenic trait? Give an example of a human polygenic trait.
A polygenic trait is a characteristic, such as height or skin color, that is influenced by two or more genes
What's the difference between dominant and recessive genes?
Dominant genes overrule others. Recessive genes are part of your genes, but not usually expressed if the dominant overrules it.