During the menstrual cycle, what triggers ovulation (the release of the mature oocyte from the Graafian follicle)?
Answer and explanation
Correct answer: B. A sudden surge in luteinizing hormone
- Step 1: Rising estrogen concentrations secreted by the maturing Graafian follicle exert positive feedback on the anterior pituitary gland around the midpoint of the ovarian cycle.
- Step 2: This positive feedback triggers an acute, rapid surge in luteinizing hormone (LH), which causes the follicle wall to rupture and release the mature secondary oocyte into the fallopian tube.
Answer
A sudden surge in luteinizing hormone.
Practise more Genetics, Homeostasis and Human Evolution.
Free questions with an explanation for every one, and full timed South Africa Matric mock tests.
More Genetics, Homeostasis and Human Evolution questions
- A heterozygous purple-flowered pea plant () is crossed with a homozygous recessive white-flowered plant (). What is the expected phe…
- Which part of the human brain regulates body temperature and water balance (osmoregulation)?
- What is the primary role of the hormone calcitonin in human calcium homeostasis?
- Which fossil hominin species was discovered by Prof. Raymond Dart at Taung in South Africa in 1924?
- In DNA replication, which enzyme is responsible for unwinding the double helix by breaking hydrogen bonds between complementary base pairs?
- What term describes the evolutionary process whereby related species evolve distinct adaptations when exposed to different ecological niches…