Name _____________________
CHAPTER 19 STUDY GUIDE
DEVELOPMENT
Section 19.1 Early Stages of Development
In your textbook, read about animal development - cleavage and morphogenesis.
Answer the following questions.

1. In what way is the beginning stage of development similar in all sexually reproducing animals?

2. What is a blastula?

3. What is the blastocoel?

4. What food source is available to a developing embryo?

Label the diagram at the right of gastrulation in a starfish. Use these choices: mesoderm endoderm blastopore ectoderm archenteron

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In your textbook, read about animal development - neurulation, and twinning.
For each statement below, write true or false.
______11. The formation of the neural tube marks the beginning of the nervous system in the developing embryo.

_____12.   The brain and spinal cord develop from the neural tube.

_____13.   Cell division ends when differentiation begins.
_____14.   Fraternal twins develop from two different eggs fertilized by different sperm.

Section 19.2 Patterns of Animal Development
In your textbook, read about metamorphosis.

Complete each statement.

1. The larval form of the frog is called a(n)

2. Animals that develop outside the female go through a series of changes in body structure known as

3. The life cycle of the grasshopper has ___________________  stages of development.

4. The immature second stage in which a frog can live on its own is called the

5. After a period of active growth, the larva develops into a(n) ___________________

6. Gas exchange in the larval stage of frogs occurs in __________________ pairs of ______________________.

In your textbook, read about the amniotic egg.
Label the diagram below of an amniotic egg. Use these choices:
	egg shell	amnion	embryo	allantois	yolk sac	chorion

Section 19.2 Patterns of Animal Development continued
In your textbook, read about internal development.
Circle the letter of the choice that best completes the statement.

14. Placental animals
a. bear small, physically immature young.
b. have no means of providing the .embryo with food or oxygen.
c. form internal tissue that provides food and oxygen to the embryo. . 
d. trap carbon monoxide in the embryo.

15. The eggs of placental mammals are fertilized in
	a.	the uterus.	.	c.	the cervix.
	b.	the oviduct.	d.	the ovaries.

16. Pregnancy begins when 
a. an egg is fertilized. 		b. a zygote forms.
c. the uterine wall thickens. 	d. implantation occurs.

17. The first membrane that forms around the embryo is
	a. the chorion.	c.	the capillaries.
	b.	the amnion.	d.	the uterine wall.

18. Blood is transported between the embryo and the placenta by means of
	a.	the amnion.	c.	the umbilical cord.
	b.	the uterine wall.	d.	the mother's vena cava.

19. There is a separate placenta for each developing embryo, except for
	a.	most fraternal twins.	c.	most identical twins.
	b. some fraternal twins.	d.	triplets and quadruplets.

Complete the statement.
20. Nutrients and oxygen diffuse from the mother's blood to the embryo's blood through the capillaries of the _____________________.
21. Carbon dioxide from the embryo is ultimately exhaled by the __________________.
22. The blood supplies of the embryo and the mother do not actually _______________.
23. The embryo's oxygen supply comes from oxygen taken in ____________________.
24. Besides food and oxygen, _________________	. and ____________________ also pass from mother to embryo.
Section 19.2 Patterns of Animal Development continued
In your textbook, read about birth.
Complete the table by checking the correct column(s).

Developin Fetus	1st Trimester	2nd Trimester	3rd Trimester	
25. is nourished by the placenta				
26. can survive with special care if born prematurely				
				
27. begins to form eyes and ears				
28.  triples its mass				
	Determine if the statement is true. If it is not, rewrite the italicized part to make it true.
29.  Labor begins with a series of vaginal contractions.

30. The amniotic sac bursts during labor, and the ovaries and the opening of the vagina dilate.

31. The fetus is pushed downward in the uterus as contractions become more intense.

32. The positioning of the fetus in a head-down, face-up position is called birth.

33. The stages of labor are dilation, expulsion, and afterbirth.

34. Afterbirth is the stage of birth in which the placenta is expelled.

35. The navel is the place where the placenta was attached to the mother's body.

36. In amphibians, reptiles, birds, and mammals, most differentiation is completed before hatching or birth.