CORRECT ANSWERS 2025/2026
Which of the following occurs for the first time in pachytene prophase I of meiosis? - CORRECT
ANSWER -Synapsis and crossing over occurs
Synapsis only occurs during meiosis, which of the following accurately describe this event? -
CORRECT ANSWER -Formation of a bivalent on specialized protein structure
The Tasmanian devil, Sarcophilus harrissi, has 14 chromosomes. If nondisjunction of
chromosome 5 occurs in meiosis I, which of the following best describes the n of the resulting
gametes? - CORRECT ANSWER -Two germ cells will be n=8 and two will be n=6
Above is karyotype of your patient. Which of the following BEST describes what you would tell
this patient's parents? - CORRECT ANSWER -This is a 48 XXY, two extra chromosomes
You have made a transgene that expresses green fluorescent protein (GFP) in spermatogonia
only. If you are examining a transverse section of the testes where would you expect to find GFP
positive (GFP+) cells? - CORRECT ANSWER -Associated with the Sertoli cells in the seminiferous
tubule.
The switch from mitosis to meiosis in spermatogenesis is regulated by levels of
and this is induced by . Fill in the blanks. - CORRECT ANSWER -low, glial cell derived
neurotrophic factor (GDNF), follicle stimulating hormone (FSH)
Spermatozoa nuclei are transcriptionally silent. Which of the following BEST explains this? -
CORRECT ANSWER -Replacement of histones with protamines