Non-Mendelian And Sex Determination Genetics Flashcards
(21 cards)
What is epistasis?
One gene controls the expression of another
Epistasis can influence the phenotype by masking the effects of other genes.
Define deposition gene.
A gene that contributes to the physical deposition of substances in an organism
Deposition genes can affect traits such as skin color or flower pigmentation.
What are polygenic traits?
Traits controlled by multiple genes
Examples include height, skin color, and eye color.
What is pleiotropy?
One gene influences multiple traits
Pleiotropic effects can complicate the inheritance patterns of traits.
What is sickle cell anemia?
A recessive mutation of one hemoglobin gene
Individuals with homozygous sickle cells exhibit sickling, while heterozygous individuals may show traits without full disease symptoms.
True or False: In sickle cell anemia, a heterozygous individual expresses the full phenotype of the disease.
False
Heterozygous individuals can show some traits but do not typically express the full disease phenotype.
How many pairs of chromosomes do humans have?
22 pairs of chromosomes (all but 1) are autosomes.
What are sex chromosomes?
Sex chromosomes are not homologous.
What is the X chromosome known for?
The X chromosome is large and contains many genes for male and female traits, as well as non-gender traits.
What is the Y chromosome known for?
The Y chromosome is small, containing approximately 70 genes, one of which is the SRY gene.
What is the role of the SRY gene?
The SRY gene is epistatic over other sex-specific genes. If present, male genes are expressed; if absent, female genes are expressed.
What are the sex chromosome combinations for females and males?
XX represents female; XY represents male.
What are sex-linked traits?
Sex-linked traits are non-gender specific genes carried on the X chromosome.
What is an example of a sex-linked trait?
Red/green color blindness is a trait linked to the X chromosome.
D represents the gene for normal vision.
What are the two main types of molecular genetics?
The two main types are DNA and RNA.
What does DNA stand for?
DNA stands for deoxyribonucleic acid.
What does RNA stand for?
RNA stands for ribonucleic acid.
What are DNA and RNA polymers made of?
They are polymers of nucleotides.
What components do nucleotides have?
Nucleotides have a nitrogenous base and a 5-carbon sugar.
What is the sugar in DNA?
The sugar in DNA is deoxyribose, which has no oxygen (H).
What is the sugar in RNA?
The sugar in RNA is ribose, which has oxygen (OH).
