Lecture 11- Meiosis Flashcards
What are autosomes/somatic cells?
Any chromosome that is not a sex chromosome
How many autosomes do humans have?
23 pairs-> 44 total autosomes
Are somatic cells haploid or diploid?
Diploid (2n)
What are the sex chromosomes for a male human?
XY
What are the sex chromosomes for a female human?
XX
From when to when does the human life cycle occur?
From conception to production of offspring
What ploidy change occurs during fertilization?
Haploid (n) + Haploid (n) → Diploid (2n)
What does fertilization result in?
Zygote
What ploidy change occurs during meiosis?
Diploid (2n) → haploid (n) [ploidy is halved]
What is the overall goal of meiosis?
Produce 4 genetically unique daughter cells
How many chromatids are present in a human somatic cell following interphase?
92
When does ploidy change during meiosis?
Anaphase I
What is the longest stage of meiosis?
Prophase I
When does chromosomal crossover occur?
Prophase I
What is synapsis?
Process by which homologous chromosomes pair up and form a tetrad
What is the name of a chromosome that has undergone crossing-over?
Recombinant chromosome
What occurs during anaphase I?
Homologous chromosomes separate (disjunction)
True or False: Cells are still diploid (2n) following meiosis I
False; following meiosis I, each cell is haploid (n)
True or False: Cells undergo interphase following meiosis I, before proceeding to meiosis II
False; cells only go through interphase once per cycle
True or False: Crossing-over occurs once more during prophase II
False; chromosomal crossover only occurs during prophase I
What occurs during anaphase II?
Sister chromatids are separated
True or False: A homologous pair is two sister chromatids joined at the centromere
False; a homologous pair consists of one maternal chromosome and one paternal chromosome
