Chapter 10 Lesson 4 Flashcards
What is the definition of nondisjunction?
When chromosomes do not separate properly during meiosis
What is the definition of trisomy?
A diploid cell which has three copies of the chromosomes (2n+1)
What is the definition of monosomy?
A diploid cell which has one copy of the chromosomes (2n-1)
What is the definition of autosomes?
Any chromosome which is not a sex chromosome
What is the definition of sex chromosomes?
A specific chromosome involved in determining the sex of an organism
What is the definition of a barr body?
A densely stained, inactivated X chromosome found in the somatic cells of most female mammels
What is the definition of deletion?
When a gene is deleted from the normal chromosome
What is the definition of duplication?
When a gene is copied in a normal chromosome
What is the definition of inversion?
When a genes genetic sequence is reversed in a normal chromosome
What is the definition of translocation?
When two genes swap places in normal chromosomes
What does nondisjunction lead to?
The production of an extra, or a missing chromosome
What determines a humans biological sex at birth?
The sequence of sex chromosomes
What happens to a zygote if duplication happens?
The zygote may have three versions of a gene rather than two, and it may make too much of some protiens
What happens to a zygote if deletion happens?
The zygote may have one version of a gene rather than two, and it may not make enough functional protiens
What happens to a zygote if inversion happens?
The zygote may have trouble pairing chromosomes for mitosis – causes trouble making gametes
What happens to a zygote if translocation happens?
The zygote may be missing genes and have extra genes at the same time
If a zygote has XXY sex chromosomes, which gender, and how many barr bodies will be present?
It will be male, and one barr body will be present
If a zygote has XXX sex chromosomes, which gender, and how many barr bodies will be present?
It will be female and two barr bodies will be present
