Chapter 2 Flashcards
heredity
transmission of biological processes from one generation to another
Epigenetics
Heritable variations in gene expression that do not involve DNA sequence changes
Chromosomes
-thread-like structure made of DNA and proteins
-Organizes and packages DNA during cell division
Gene
-a segment of DNA that codes for a specific protein of RNA
-contains instructions for building proteins or RNA
-each chromosome contains thousands of genes
Down Syndrome
Abnormalities in the 22 pairs of autosomes
XYY syndrome
Abnormalities in sex chromosomes
Phenylketonuria
transmitted recessive gene that is a genetic abnormality
Huntington Disease
a fatal and progressive genetic abnormality. symptoms include uncontrollable muscle movements, loss of intellectual functioning and personality change
Sickle Cell Anemia
genetic abnormality that 5% of the world are carriers of this gene. it impairs cognitive skills, blindness; heart and liver failure.
Tay-Sachs Disease
a genetic abnormality caused by a recessive gene. causes central nervous system to degenerate, resulting in death
Cystic Fibrosis
genetic abnormality that children suffer from excessive production of thick mucus that clogs the pancreas and lungs
Hemophelia
a genetic disorder in which blood does not clot properly; on x chromosome
4 Prenatal Tests
Amniocentesis, Chorionic Villus Sampling, Ultrasound, Blood Tests
Genotypes
Sets of traits we inherit from our parents
Phenotypes
actual set of traits; develop because of both genetic and environmental influences
What relationships have 50% genetic overlap
- parents with their children
- siblings
Monozygotic
Identical twins where the zygote divides into two cells that separate.
Dizygotic
Fraternal twins: two ova are produced and are fertilized by a different sperm cells
Reasons for Male Infertility
-low sperm count
-diabetes
-STI’s
-overheating of the testes
-aging
-deformity of sperm
Reasons for Female Infertility
-irregular or lack of ovulation
-infections can scar fallopian tubes
-endometriosis (obstructs fallopian tubes; uterus lining is backed up into abdomen and causes pain
Fertility Treatments
-Assisted Reproductive Technology
-artificial insemination
-IVF
donor IVF
when is the Germinal Stage
0-2 weeks
what happens in the Germinal Stage
-fertilization
-formation of the blastocyst
-implantation
when is the Embryonic Stage
3-8 weeks
what happens in the Embryonic Stage
-formation of the ectoderm, endoderm, and mesoderm
-formation of major organs
when is the fetal stage
9-40 weeks
what is the Fetal Stage
-sexual differentiation
-rapid growth of fetus
-strengthening of organs
-fetus begins to sense sound and light at 13 weeks
cephalocaudal
develops from head to tail
proximodistal
develops from near to far trends
ectoderm
-outer-layer of cells develops into nervous system, sensory organs, nails, hair, outer layer of skin
neural tube
Develops at 21 days and is two ridges appear in embryo and fold
endoderm
inner layer of embryo that forms digestive and respiratory system, liver and pancreas
mesoderm
Middle layer of cells develops into excretory, reproductive and circulatory system, muscles and skeleton and the inner layer of skin
The Amniotic Sac
It surrounds the fetus and had amniotic fluid surrounding the sac which acts as a airbag, protecting it
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