210 ❯ STEP 4. Review the Knowledge You Need to Score High
12.Which structure is usually the site of fertilization
in humans?
A. Cervix
B. Uterus
C. Oviduct
D. Ovary
E. Endometrium
13.Which of the following explains the mechanism
by which the neural plate develops in human
embryos?
A. Induced fit
B. Homeotic gene determination
C. Induction
D. Negative feedback
E. Gastrulation1. B
2. E
3. D
4. C
- C—The cervix is the only structure listed here
that is a part of the female reproductive anatomy.
The epididymis is the site of sperm storage and
maturation while it awaits ejaculation. The semi-
nal vesicles are the convenience store, providing
the sperm with the necessary materials to survive
its journey from ejaculation to fertilization. The
vas deferens is the tunnel connecting the epi-
didymis to the urethra. The interstitial cells are
the cells that produce the hormones, such as
testosterone, vital to male sexual function. - A—At the beginning of each menstrual cycle,
GnRH is released from the hypothalamus and
travels to the anterior pituitary gland to induce the
release of FSH and LH. FSH induces the develop-
ment of the follicle and causes the follicle to release
estrogen, which triggers the hypothalamus to
dump more GnRH into the system. This GnRH
acts on the anterior pituitary to produce the LH
surge, which triggers ovulation. The estrogen feeds
back to the hypothalamus to induce the release of
large amounts of LH that ultimately lead to
increased production of even more estrogen.
7. C—The heart is part of the circulatory system
and is derived from the mesoderm.
8. B
9. C - E
- A
- C—The oviduct, or the fallopian tube, is where
fertilization normally occurs in humans. The
uterus is where implantation and development
of the embryo normally occur. The embryo usu-
ally implants on the wall of the uterus—the
endometrium. The cervix is the narrow pathway
from the uterus to the vaginal opening. The
ovary is the site of egg production. - C—Remember induction. It is a concept loved
by the AP Biology exam writers. Inductionis the
ability of cells to influence the development of
other cells by either physical contact or chemical
signals.Homeotic genesare genes that determine
how segments of an organism will develop.
Induced fitis how enzymes and substrates inter-
act.Gastrulationis the separation of the cells of
the developing embryo into the three primary
germ layers. Negative feedbackis the reduction in
production of a substance due to high levels
already present in circulation.