Mod 2 Inheritance Flashcards
(31 cards)
Principle of Dominance
Some alleles are dominant while others are recessive. An organism with at least one dominant allele will display the effect of the dominant allele.
Principle of Segregation state?
Sexually reproducing organisms possess genes that occur in pairs and that only 1 member of this pair is transmitted.
Principle of Independent Assortment?
Genes at different loci are transmitted independently.
Define genotype.
The genetic makeup of an organism, such as PP or pp.
Define phenotype.
The actual observable characteristics of an organism, such as the color of flowers.
In autosomal recessive disorders, what is the recurrence risk if both parents are carriers?
25%
What is the difference between dominant and recessive traits?
Dominant traits require only 1 copy of a gene to be expressed, while recessive traits require 2 copies for expression.
What are Mendelian Disorders?
Phenotypes due to alterations at a single gene, including autosomal dominant, autosomal recessive, X-linked dominant, and X-linked recessive.
What is a proband in pedigree analysis?
The first person in whom the disease is diagnosed in the pedigree.
What is the recurrence rate for autosomal dominant inheritance?
50%
Which sex is most commonly affected by X-linked recessive disorders?
AMABs (Assigned Male At Birth)
True or False: All AFAB children of an affected individual in X-linked recessive inheritance will be carriers.
True
What is X inactivation?
One of the X chromosomes in AFABs is randomly inactivated in early development.
What is the significance of calico cats in genetics?
Calico cats have black and orange patches corresponding to two populations of cells with different active X chromosomes.
When does embryonic development begin?
At fertilization.
What occurs during days 1-5 of human development?
Rapid cell division and blastocyst formation.
What is teratology?
The study of abnormal fetal development and malformations caused by teratogens.
List some examples of teratogens.
- Cocaine
- Alcohol
- Vitamin A
- Infections
What are TORCH infections?
A group of infections that can cause congenital disabilities, including Toxoplasmosis, Other infections, Rubella, Cytomegalovirus, and Herpes Simplex Virus.
What is the most potent known teratogen?
Isotretinoin
What are the effects of alcohol as a teratogen?
Growth inhibition, CNS dysfunction, characteristic facial dysmorphology, cognitive disabilities.
What is gene therapy?
Genetic alteration of cells to cure disease, often using viral vectors.
