Answer:
in the wall of the right atrium of the heart.
Explanation:
The sinoatrial node (SA), consisting of spindle-shaped cells, initiates the electrical activity of the heart. From its location in the right atrium in proximity to the superior vena cava, the electrical activity spreads to the atria, whose cells are larger than those of the SA.
19. B - mitochondria
20. D - vegetative structure
21. C - inducing a mutation
22. A - phosphates
23. C - fungi
24. A - provides support
25. C - sponges
26. B - opposite charges
27. D - asexual reproduction
28. not sure about this one sorry
29. D - all of the above
30. A - prevents ions and large molecules from passing through the membrane
Answer:
ji!\uuisdrhttojejltjegbkflccbdnmcifhgagaakpot
The correct answer is "ovulation" and "corpus luteum" respectively. In ovulation, the egg ruptures from the mature follicle (called the Graafian follicle). This process is preceded by the sudden rise in luteinizing hormone. The follicle now becomes the corpus luteum, actually does not secrete estrogen, it secretes progresterone which prepares the uterine lining for pregnancy.