NCLEX : Developmental Biology

Study concepts, example questions & explanations for NCLEX

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Example Questions

Example Question #11 : Developmental Biology

Which of the following tissue types is derived from the ectoderm?

Possible Answers:

Teeth

Skin, hair, and nails

All of these are correct

Nervous tissue

Correct answer:

All of these are correct

Explanation:

The ectoderm is the outer-most germ layer of a developing fetus. It forms the nervous system, teeth, skin, hair, nails, sweat glands, mouth, and anus.

Example Question #101 : General Biology

Which of the following tissue types is not derived from the mesoderm?

Possible Answers:

Pericardium

Muscle cells

Thyroid

Red blood cells

Correct answer:

Thyroid

Explanation:

The mesoderm forms skeletal muscle, cardiac muscle, smooth muscle, connective tissue, the pericardium (in addition to several other membranous sacs such as the peritoneum) and red blood cells. It also gives rise to cartilage and bone, the dura mater, the kidneys, and the adrenal glands.

The thyroid is derived from the endoderm. 

Example Question #13 : Developmental Biology

Which of the following medications is known to have teratogenic effects?

Possible Answers:

Isotretinoin

All of these

Warfarin

ACE inhibitors

Correct answer:

All of these

Explanation:

Multiple forms and classes of medication have been shown to cause birth defects. These include ACE inhibitors, anti-epileptics such as phenytoin and valproic acid, isotretinoin and other forms of high-dose vitamin A, and blood thinners such as warfarin, among others.

Example Question #14 : Developmental Biology

Fertilization generally occurs in what location?

Possible Answers:

In the fundus of the uterus

In the fimbrae

The distal two-thirds of the fallopian tube

In the body of the uterus

Correct answer:

The distal two-thirds of the fallopian tube

Explanation:

Fertilization happens in the fallopian tube, most frequently in the distal two-thirds of the tube. 

Example Question #102 : General Biology

__________ is the fetal structure that allows approximately 20-30% of blood to bypass the liver and flow from the umbilical vein to the vena cava.

Possible Answers:

The umbilical vein

The ductus venosus

The foramen ovale

The ductus arteriosus

Correct answer:

The ductus venosus

Explanation:

The ductus venosus is a small shunt that allows a portion of fetal blood to bypass the liver and flow from the umbilical vein to the vena cava. This allows more oxygenated blood to be available for the developing fetal brain.

The ductus arteriosus and foramen ovale are both fetal cardiac shunts.

Example Question #11 : Developmental Biology

The placenta secretes all of the following hormones except __________.

Possible Answers:

Human chorionic gondotropin (hCG)

Estrogen

Aldosterone

Human placental lactogen (hPL)

Correct answer:

Aldosterone

Explanation:

The human placenta secretes estrogen, progesterone, human chorionic gondotropin (hCG), and human placental lactogen (hPL). Aldosterone is produced by the adrenal gland. 

Example Question #12 : Developmental Biology

The initial single-celled fertilized egg is known as the __________.

Possible Answers:

blastocyst

embryo

zygote

morula

Correct answer:

zygote

Explanation:

A zygote is a eukaryotic cell formed by a the joining of two gametes (sperm and egg). The zygote then goes on to divide several times till it forms a small clump of cells termed a morula. The next stage is the formation of a blastocyst, which is the final stage before development into an embryo.  

Example Question #111 : General Biology

An embryo implants __________ days after ovulation.

Possible Answers:

5-7

10-12

1-5

7-10

Correct answer:

7-10

Explanation:

The zygote has developed into an embryo and reached the uterus by day 5 and will generally implant on day 7-10 after ovulation.

Example Question #13 : Developmental Biology

The majority of first trimester miscarriages are due to __________.

Possible Answers:

chromosomal abnormalities

None of these

exercise

lifting heavy objects

Correct answer:

chromosomal abnormalities

Explanation:

The most common cause of first trimester miscarriage is chromosomal abnormalities. These can occur in as many as 1 in 4 pregnancies, and cause the developing embryo issues that are not compatible with life. 

Lifting heavy objects and exercise are NOT generally responsible for triggering miscarriage (though they could potentially trigger a miscarriage in individuals with underlying conditions or other risk factors). 

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