| Term | Definition |
|---|
| Neural tube | Formed in the third week of development by the fusion of the folds that form in the ectoderm; its cells develop into the brain and spinal cord |
| Neural tube defects | Caused by the arrest of the normal development and closure of the neural tube |
| Spina bifida | Lower vertebrae does not develop; spinal cord sticks out of back bone |
| Anancephaly | When cranial bones do not develop; exposed brain degenerates |
| Placenta | Allows oxygen and nutrients to diffuse from maternal blood into fetal blood and allows wastes to leave the fetus; no actual contact between maternal and fetal blood |
| Fetal portion | Portion of the placenta that is formed from the chorion; develops chorionic villi |
| Maternal portion | Portion of the placenta formed by part of the endometrium |
| Umbilical cord | Connection betwee placenta and embryo |
| Late embryonic development | Occurs in the 4th-8th week; rapid development of brain/head; heart is becomes 4-chambered; digits appear in 7th week; by 8th week hear beats, eyes/nose formed, genitals form; considered an embryo |
| Fetal development | Last 30 weeks of development; tissues and organs now grow and differentiate; after week 33, fetus can survive prematurely |
| Chromosome | Protein and DNA coiled together; humans have 23 pairs for a total of 46 |
| Gene | Made of DNA and contains instructions for making protein; every person has two copies of each gene - one from each parent |
| Allele | One copy of a gene; 1/2 of the gene pair |
| Segregation of alleles | During gamete formation, alleles within a pair seperate and are sent to different gametes |
Combine with other sets
Share on Facebook
Share on MySpace