COMPS Study guide- Embryological Dev't of Cleft P. (O1) Flashcards
Define “meiosis”
The process of cell division and production of a sperm and egg.
define “gamete”
The germ cell; sperm or egg.
how many pairs of chromosomes does the egg have? the sperm?
egg has 22 chromosomes plus an “x”
sperm has 22 chromosomes plus a “y” (23 pairs for 46 total chromosomes in every cell)
Define “mitosis”
normal cell division; the replacement process that happens when cells are damaged or die off.
What are the two processes of cell division in human reproduction?
- Segmentation: cell divides & makes another cell identical to it; 3 phases-
a) blastomere- cell’s 1st division
b) morula- 72 hours after fertilization (3 days)
c) blastocyst- 6 days after fertilization - Cell differentiation: 3 phases-
a) Trophoblast- wrapping that covers blastocyst & becomes the placenta.
b) Gastrulation- inner cell mass turns inside out (9-12 days); when things can go wrong.
c) Embryonic disk- 3 tissue layers.
what are the 3 tissue layers of the embryonic disk?
- Ectoderm: outer layer (develops into skin, hair, teeth)
- Mesoderm: middle layer (bone, cartilage, muscle, & blood vessels)
- Endoderm: inner layer (lines the digestive tract, respiratory tract, & thoracic cavity)
a) define “genes”
b) what are they made of?
the building blocks of genetics; made up of DNA
What are chromosomes made up of?
genes. can be different sizes & have different features.
What is a strand of DNA made of?
Neucleotide pairs. Made up of sugar and phosphate, which makes a base.
what is the base of DNA made up of?
thymine, adenine, guanine, & cytosine
define “mutation”
an error in reduplication that can occur during any part of the mitosis process
what is a “spontaneous mutation”?
Parents are normal but the offspring is not. This is opposite of “inerrited factor” in which the parents pass a mutation to the offspring
Name some mutations
Monosomy, trisomy (Trisomy 21 - down syndrome), deletion, inversion, translocatoin
what is clefting called when it is not associated with any syndrome?
“isolated cleft”
what is an autosomal dominant gene?
2 parents: 1 normal and 1 with a mutated gene. child will have the mutation, and it may be passed on in future generations.
what is an autosomal recessive gene?
this trait will NOT show up in the offspring unless both parents carry the trait.
what is an x-linked chromosomal syndrome?
mother has abnormal x chromosome; any sons will have an abnormality. (e.g., Fragile X Syndrome)
what is a “multifactoral” mutation?
Medical problems associated with the affects of genes AND lifestyle and/or environmental factors (such as mother being exposed to radiation)
Define “syndrome”
A condition that has a SINGLE cause (trisomy, monosomy, etc), with a multitude of UNRELATED symptoms.
T/F: cleft palate tends to be a spontaneous genetic mutation (e.g., not inherited).
TRUE (isolated cleft)
