(c) The is the outer layer of embryonic cells.
(d) The is the middle layer of embryonic cells.
(e) The is the internal layer of embryonic cells.
Answers: (a) zygote; (b) embryo; (c) ectoderm; (d) mesoderm; (e) endoderm.
From seven weeks to birth, the new being is called a fetus.Fetal development
is rich and complex. The cells continue to divide, and they become specialized in
their structures and functions. Brain cells (neurons), skin cells, hair cells, fat cells,
and many other kinds of cells form. The head, limbs, fingers and toes, and other
features of the body appear. In the typical case, the stage of the fetus lasts a little
over seven months, making the total time from conception to birth about nine
months.
At birth the new being is called a neonate.Neomeans “new.” And natemeans
“birth.” Thus the word neonatesimply means “newborn.” If the neonate loses
weight after birth, then he or she is not referred to as an infant until birth weight
has been regained. The word infant is from Latin roots meaning “without
speech.”
(a) From seven weeks to birth, the new being is called a.
(b) At birth the new being is called a.
(c) The word is from Latin roots meaning “without speech.”
Answers: (a) fetus; (b) neonate; (c) infant.
Freud’s Theory of Psychosexual Development:
From the Oral to the Genital Stage
The infant is on the threshold of continuing biological and psychological devel-
opment. Our principal concern in this and future sections of this chapter is with
psychological development. Freud’s theory of development has been highly influ-
ential. First proposed about eighty years ago, it has had a large impact on the way
in which both psychologists and parents have thought about sexual development
in children. It has also influenced child-rearing practices.
According to Freud, there are five stages in psychosexual development. Psy-
chosexual developmentrefers to the development of a sexual identity, attitudes
toward sexual behavior, and emotional reactions to sexual stimuli. Sexual devel-
opment, in Freud’s view, is much more than biological. Identity, attitudes, and
emotional reactions are psychological in nature. That is why Freud used the term
psychosexualinstead of simply sexualto refer to the kind of development he wanted
to study.
Developmental Psychology: How Children Become Adults 157
