Chapt
DEVELO
HEREDITY
SEELEY'S ESSENTIALS
PHYSIOLOGY,
, DEVELOPMENT, HE
PRENATAL DE
The prenatal period, the period from
into three parts:
(1) During approximately the first
germ layers are formed;
(2) from about the second to the ei
organ systems come into existenc
(3) during the last 7 months of the
grow and become more mature.
Between the time of fertilization and
developing human is called an embry
developing human is called a fetus.
, DEVELOPMENT, HE
EARLY CELL
About 18–36 hours after fertilization,
Those two cells divide to form four ce
on. Even though the number of cells
decreases, so that the total mass of c
the zygote. These cells have the abili
tissues. As a result, the total number
or reorganized during this period wit
DEVELOPMENT OF
AND IMPLA
DEVELO
HEREDITY
SEELEY'S ESSENTIALS
PHYSIOLOGY,
, DEVELOPMENT, HE
PRENATAL DE
The prenatal period, the period from
into three parts:
(1) During approximately the first
germ layers are formed;
(2) from about the second to the ei
organ systems come into existenc
(3) during the last 7 months of the
grow and become more mature.
Between the time of fertilization and
developing human is called an embry
developing human is called a fetus.
, DEVELOPMENT, HE
EARLY CELL
About 18–36 hours after fertilization,
Those two cells divide to form four ce
on. Even though the number of cells
decreases, so that the total mass of c
the zygote. These cells have the abili
tissues. As a result, the total number
or reorganized during this period wit
DEVELOPMENT OF
AND IMPLA
