Question

developmental chart

1. human pregnancy lasts approximately ____ weeks.
2. it can last anytime between __ and weeks after __________ and still be considered

a normal timeframe.
first trimester

1. an ____ becomes fertilized when a ______ penetrates it, creating a __________.
2. for the first eight weeks, the developing baby is called an ____________. it looks like a

___________.

1. at about __ weeks, the neural tube, which becomes the ______ and spinal ________.

is forming.

1. at about __ weeks, the ______ begins to pump ____. tiny ________ buds

appear, ______ and ______ are formed, and ________ and _____ develop.

1. during the first trimester, which lasts up to __ weeks, all major body ________ and

systems are formed but not completely ____________.

1. this is a critical period for development of the ________, central __________ system,

upper and lower ________, ____ and ______, ________ and palate, and
most organs. any damage at this stage can result in major damage or ______________.

1. at __ weeks, when most ____________ have formed, the embryo is called a

___________.
second trimester

1. the fetus moves, ________, ____________, and can hear the mother’s

___________.

1. it begins to __________ and ____________ at regular intervals.
2. the skin changes from a transparent __________ to a wrinkled ______, and is covered

with soft, fine ______.

Explanation:

The questions cover human prenatal development, a core topic in Biology focusing on embryonic and fetal growth stages. Answers are based on standard developmental biology knowledge.

Answer:

1. 40
2. 37; 42; conception
3. egg; sperm; zygote
4. embryo; tadpole
5. 3-4; brain; cord
6. 6; heart; blood; limb; eyes; ears; fingers; toes
7. 12; structures; developed
8. heart; nervous; limbs; eyes; ears; lips; miscarriage
9. 8; organs; fetus
10. kicks; swallows; voice
11. sleep; wake
12. layer; appearance; hair (lanugo)