Patterns of Inheritance Flashcards
What is the significance of Mendel’s work in genetics?
Mendel’s work laid the foundation for our understanding of inheritance patterns and how traits are passed from one generation to the next.
What is Mendel’s first law of inheritance, and what does it explain?
Mendel’s first law, the “law of segregation,” states that each individual has two factors (alleles) for each trait, and these factors segregate during gamete formation. Fertilization results in each new individual having two factors for each trait.
What is the “law of independent assortment,” and how does it relate to Mendel’s experiments?
The “law of independent assortment” states that each pair of factors segregates independently of other pairs. Mendel formulated this law based on his observations in two-trait inheritance experiments, which demonstrated that different traits segregate independently during gamete formation.
How is probability used to predict genetic crosses, and which laws does it rely on?
Probability is used to predict genetic crosses based on the laws of segregation and independent assortment. The rule of multiplication is applied to calculate the chances of specific genotypes in offspring by considering the probabilities of each allele segregating independently.
What is the relationship between Mendel’s laws and meiosis?
Mendel’s laws are closely related to meiosis, the process of cell division that leads to the formation of gametes (sperm and egg cells). Meiosis explains how alleles segregate and are distributed to gametes, supporting Mendel’s laws.
What are autosomal traits, and why are they important in genetic analysis?
Autosomal traits are traits controlled by genes located on autosomes (non-sex chromosomes). They are important in genetic analysis because they often follow Mendel’s laws of inheritance and can help understand the transmission of genetic traits within families.
What is a pedigree, and how is it used in genetic analysis?
A pedigree is a chart representing a family’s history with respect to a specific genetic trait. It is used in genetic analysis to establish inheritance patterns, determine the likelihood of passing on genetic traits, and make informed decisions about genetic testing.
What is an autosomal recessive disorder, and how does it appear in pedigrees?
An autosomal recessive disorder is a genetic condition that requires two copies of a mutated allele for an individual to express the disorder. In pedigrees, it often appears as affected individuals having unaffected carrier parents.
Provide examples of autosomal recessive genetic disorders.
Examples of autosomal recessive disorders include cystic fibrosis, alkaptonuria, sickle-cell disease, and methemoglobinemia.
What are X-linked traits, and how do they differ between males and females?
X-linked traits are traits controlled by genes located on the X chromosome. They differ between males and females because males inherit their X chromosome from their mothers, while females inherit one X chromosome from each parent. As a result, X-linked traits often follow different inheritance patterns in males and females.
What is the “law of segregation,” and how does it relate to the inheritance of traits?
The “law of segregation” states that each individual has two alleles for each trait, and these alleles segregate during gamete formation, with each gamete carrying only one allele. This law explains how traits are passed from one generation to the next.
Explain the difference between genotype and phenotype.
Genotype refers to the combination of alleles an organism carries for a specific trait, while phenotype represents the physical appearance or expression of that trait. Genotype is the genetic makeup, while phenotype is the observable characteristic. Genotype
What is a testcross, and why is it used in genetics?
A testcross is a genetic cross between an individual with an unknown genotype (usually displaying a dominant phenotype) and a homozygous recessive individual. It is used to determine if the individual with the dominant phenotype is homozygous dominant or heterozygous for a particular trait.
How does meiosis explain Mendel’s “law of segregation”?
Meiosis is the cell division process that reduces the chromosome number in gametes. During meiosis, homologous chromosomes segregate, leading to gametes with one allele for each trait. This process aligns with Mendel’s “law of segregation.”
What is codominance, and provide an example of an X-linked trait that exhibits codominance.
Codominance is a genetic concept where both alleles of a gene are fully expressed, leading to a combined phenotype. An example of an X-linked trait exhibiting codominance is the ABO blood group system, where individuals with both A and B alleles express both antigens, resulting in blood type AB.
