Fetal Development and Genetics

Question 1

allele

Answer 1

internally coded inheritable information, one of two or more alternative versions of a gene at a given position or locus on a chromosome that imparts the same characteristic of that gene..

Question 2

blastocyst

Answer 2

Within the morula, an off-center, fluid-filled space appears, transforming it into the hollow ball of cells.

Question 3

embryonic stage

Answer 3

end of the second week through the eighth week

Question 4

fertilization

Answer 4

Conception, union of ovum and sperm, which is the starting point of pregnancy.

Question 5

fetal stage

Answer 5

end of the eighth week until birth

Question 6

genes

Answer 6

chromosome is made up of.

Question 7

genetic counseling

Answer 7

the process by which clients or relatives at risk for an inherited disorder are advised of the consequences and nature of the disorder, the probability of developing or transmitting it, and the options open to them in management and family planning in order to prevent, avoid, or ameliorate it.

Question 8

genetics

Answer 8

study of individual genes and their role in heritance.

Question 9

genome

Answer 9

represents his or her genetic blueprint, which determines genotype (the gene pairs inherited from parents; the specific genetic makeup) and phenotype (observed outward characteristics of an individual)

Question 10

genomics

Answer 10

relatively new science, is the study of all genes and includes interactions among genes as well as interactions between genes and the environment.

Question 11

genotype

Answer 11

the gene pairs inherited from parents; the specific genetic makeup.

Question 12

heterozygous

Answer 12

“different” alleles.

Question 13

homozygous

Answer 13

“same” alleles.

Question 14

karyotype

Answer 14

analysis of the number, form, and size of an individual’s chromosomes.

Question 15

monosomies

Answer 15

only one copy of a particular chromosome instead of the usual pair.

Question 16

morula

Answer 16

four cleavages, the 16 cells appear as a solid ball of cells or morula, meaning “little mulberry.”

Question 17

mutation

Answer 17

Any change in gene structure or location, may alter the type and amount of protein produced.

Question 18

phenotype

Answer 18

observed outward characteristics of an individual.

Question 19

placenta

Answer 19

early blastocyst trophoblasts differentiate into all of the cells that form this. serves as the interface between the mother and the developing fetus. develops at the uterine fundus.

Question 20

polyploidy

Answer 20

One type of chromosomal number abnormality, causes an increase in the number of haploid sets (23) of chromosomes in a cell

Question 21

preembryonic stage

Answer 21

fertilization through the second week

Question 22

teratogen

Answer 22

any substance, organism, physical agent, or deficiency state present during gestation that is capable of inducing abnormal postnatal structure or function by interfering with normal embryonic and fetal development.

Question 23

trisomies

Answer 23

three of a particular chromosome instead of the usual two.

Question 24

trophoblast

Answer 24

outer layer of cells surrounding the blastocyst cavity.

Question 25

umbilical cord

Answer 25

one large vein and two small arteries. Wharton’s jelly surrounds these three blood vessels and prevents compression, which would cut off fetal blood and nutrient supply. Develops end of the second week, formed from the amnion.22” long, 1” wide.

Question 26

zona pellucida

Answer 26

clear protein layer around the ovum that keeps all other sperm out once it is fertilized. Disappears after 5 days.

Question 27

zygote

Answer 27

a diploid union of of cells. Sex is determined by the sperm at this time.

Question 28

Ductus venosus shunt

Answer 28

—connects the umbilical vein to the inferior vena cava.

Question 29

Ductus arteriosus shunt

Answer 29

—connects the main pulmonary artery to the aorta.

Question 30

Foramen ovale shunt

Answer 30

—anatomic opening between the right and left atrium.

Question 31

KLINEFELTER SYNDROME

Answer 31

sex chromosomal abnormality that occurs only in males. The extra genetic material causes abnormal development of the testicles, resulting in decreased production of sperm and male sex hormones. Male is infertile, normal life expectancy.

Question 32

Turner syndrome

Answer 32

common abnormality of the sex chromosome in which a portion or all of the X chromosome is missing. It affects about 1 in 2,000 live-born female infants worldwide

Question 33

Trisomy 18

Answer 33

Edward syndrome, Affected newborns have 47 chromosomes (three at chromosome 18) and are characterized by severe intellectual disability, growth deficiency of the cranium (microcephaly), low-set ears, facial malformations, small-for-gestational-age size, seizures, drooping eyelids, webbing of fingers, kidney and congenital heart defects, rocker-bottom feet, and severe hypotonia

Question 34

Trisomy 13

Answer 34

Patau syndrome, Forty-seven chromosomes (three of chromosome 13) are present. microcephaly, cardiac defects, small eyes, kidney malformations, central nervous system anomalies, rocker-bottom feet, neural tube defects, omphalocele, cleft lip and palate, cryptorchidism, polydactyly

Question 35

Fragile X syndrome

Answer 35

Also termed Martin–Bell syndrome, is a structural abnormality X chromosome. Most common form of male intellectual disability.