Chromosome Variation Flashcards
What is a chromosomal translocation?
A segment of one chromosome becomes attached to another.
What occurs in a reciprocal translocation?
Two non-homologous chromosomes exchange genetic material.
What are unbalanced translocations?
Translocations that alter the total amount of genetic material, leading to duplications and/or deletions.
What is Familial Down Syndrome?
A condition where the majority of chromosome 21 is attached to chromosome 14, leading to three copies of genes on chromosome 21.
What are the potential effects of inversions on phenotype?
Inversions can alter phenotype through the break point effect or position effect.
What is the break point effect?
An inversion break point occurs within a vital gene, separating it into two nonfunctional parts.
What is the position effect?
A gene is repositioned in a way that alters its gene expression.
What is comparative genomic hybridization used for?
To detect chromosomal deletions and duplications, particularly in cancer cells.
What is gene-environment interaction in the context of autism?
Interactions between genetic changes and environmental factors, such as maternal infections during pregnancy, that increase autism risk.
What are copy number variations (CNVs)?
Segments of DNA that vary in copy number among members of the same species.
What factors influence the phenotypic consequences of deletions?
Size of the deletion, chromosomal material deleted, and whether the lost genes are vital to the organism.
What features do cytogeneticists use to classify chromosomes?
Location of the centromere, size, and banding patterns.
What is a karyotype?
A micrograph in which all chromosomes within a single cell are arranged in a standard fashion.
True or False: Duplications are more likely to have phenotypic effects if they involve a large piece of the chromosome.
True.
Fill in the blank: A chromosomal duplication is usually caused by abnormal events during _______.
recombination.
What are terminal and interstitial deletions?
Types of chromosomal deletions affecting different regions of a chromosome.
What are the consequences of crossing over within the inversion loop?
Can lead to unbalanced translocations or phenotypic abnormalities.
What is the significance of the G-banding technique?
It distinguishes individual chromosomes from each other, detects structural changes, and reveals evolutionary relationships.
What are the 4 forms of chromosome alteration?
- Deletion (Terminal or Interstitial)
- Duplication
- Inversion (Pericentric (includes centrinome) or Paracentric (no centrinome))
- Translocation (Simple or Reciprocal)
