a. What gland secretes LH (luteinizing hormone)? b. On what day does the LH reach its peak concentration? c. What happens to the egg in the ovary on Day 14 after LH levels reach their peak? Refer to B – Events in the Ovary.

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.

c.           is the correct answer

a bird that nests only in a particular tree species.