Multiple Choice
Which of the following chromosomal events might result in a human zygote with 45 chromosomes?
3
views
6. Chromosomal Variation
Chromosomal Mutations: Aneuploidy
Struggling with Genetics?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Which of the following best explains why some individuals have unusual chromosome combinations, such as an extra or missing chromosome?
A
Environmental factors causing gene expression changes
B
Mutations in mitochondrial DNA
C
Errors in chromosome segregation during meiosis, leading to aneuploidy
D
Crossing over between homologous chromosomes
Verified step by step guidance1
Understand that chromosomes are normally distributed equally during meiosis, the process that produces gametes (sperm and egg cells).
Recognize that errors in chromosome segregation during meiosis can lead to gametes with an abnormal number of chromosomes, a condition known as aneuploidy.
Recall that aneuploidy results when chromosomes fail to separate properly during either meiosis I or meiosis II, causing some gametes to have extra chromosomes and others to be missing chromosomes.
Note that environmental factors affecting gene expression or mutations in mitochondrial DNA do not directly cause changes in chromosome number.
Understand that crossing over is a normal process during meiosis that exchanges genetic material but does not cause changes in chromosome number.
Related Videos
Related Practice
Chromosomal Mutations: Aneuploidy practice set
Problem sets built by lead tutorsExpert video explanations