1. Which role does the placenta have in embryo growth and development?
A. Digestion of nutrients
B. Perception of stimuli
C. Transmission of electrical signals
D. Providing of nutrients and oxygen Correct
Explanation
The placenta acts as a lifeline, ferrying oxygen and nutrients from the mother's bloodstream to the developing embryo while whisking away waste. It never digests food itself (that's the mother's job), doesn't sense the environment, and isn't a nerve cable for electrical impulses.
2. Which term is used for the outer cells of the human blastocyst?
A. Embryonic disk
B. Neural plate
C. Trophoblast Correct
D. Mesenchyme
Explanation
The blastocyst has an outer coat that burrows into the uterine wall and eventually helps form the placenta - this layer is known as the trophoblast. The embryonic disk is the inner cluster that becomes the baby, while the neural plate and mesenchyme appear much later in development.
3. Which time period is regarded as the germinal period of prenatal development?
A. The first two weeks of postconception Correct
B. The third to the eighth week of postconception
C. The ninth to sixteenth week of postconception
D. The ninth week until birth
Explanation
The germinal period is the whirlwind first fortnight after conception: rapid cell division, travel down the fallopian tube, and implantation. Weeks 3-8 are the delicate embryonic period of organ formation, and everything from week 9 onward is the longer fetal period of growth and refinement.
4. How do teratogens affect prenatal development?
A. They can cause depression in newborns
B. They can cause anoxia in newborns
C. They can cause malformed facial features in newborns Correct
D. They can cause autism in newborns
Explanation
Teratogens are notorious for hijacking critical windows of development and producing visible structural defects - think the distinctive facial features linked to fetal alcohol syndrome. While behavioral or neurological issues can sometimes appear later, the hallmark signature is physical malformation.
5. A seven-month-old baby begins vocalizing consonant-vowel sequences such as ma-ma-ma and da-da-da. Which form of intentional vocalization does this illustrate?
A. Gesturing
B. Cooing
C. Babbling Correct
D. Holophrasis
Explanation
Around 6-9 months, babies enter the delightful babbling phase where they string consonants and vowels together in repetitive syllables. Earlier they cooed with goo-goo sounds, later they'll use single words meaningfully (holophrasis), and gesturing is a whole different channel.