chapter 22-24 Flashcards
in humans a normal pregnancy is defined as?
the presence of developing offspring in the uterus.
the corona radiata is the protective?
layer farthest from the oocyte cell membrane.
the chorion is the first extraembryonic membrane to form.
true.
the gastrula contains three layers of embryonic tissues.
true
the ectoderm become
the nervous system and skin.
the fetal stage of development is from?
the beginning of the ninth week to birth.
the ductus arteriosa connects the pulmonary trunk to the
the aorta
trophoblast cell secrete this hormone to keep the corpus luteum intact?
hCG
fetal cells are more efficient at absording nutrients from the maternal blood than maternal cells.
true.
the post natal period is defined as the period.
from birth to death.
the zygote divides rapidly without a change in size is which stage instead?
cleavage.
the stage of a hollow ball of cells with an inner call mass is called?
blastocyst.
fertilizations occur in which location?
the first third of the uterine tube.
genes are defined as?
sequences of DNA that encodes proteins.
recessive refers to the?
allele expression that is masked.
a Punnett square?
- allows for probabilities of genotypes.
incomplete dominance occurs?
when one phenotype is between the two homozygotes.
a genotype describes?
- a particular allele
- the DNA an individual possesses.
codominances occurs?
when the phenotypes is between the two homozogtes.
polyploidy refers to?
the addition of a set or sets of chromosomes.
trisomy refers to?
having an extra chromosome.
autosome in humans are?
the first 22 chromosomes.
alternative forms (different DNA sequences) of genes are called?
alleles.
genes on the autosomes are paired, just like homologues.
true.
dizgotic twins develop from one fertilized zygotes.
false.
the sex chromosomes are the 22nd chromosomes.
false.
