Chapter 2 learning objectives Flashcards
What are the cahracteristics of the zygotes?
at conception, 23 chromosomes from the sperm join with 23 from the ovum to make up the set of 46 that will be reproduced in the each cell of the new baby’s body. Each chromomosome consists of long string of deoxyribonucleic acid (DNA) made up ofr segments called genes. The baby’s sex is determind by the 23rd crhomomsomes, as a pattern of XX for girl and XY for boys
What risks are associated with assisted reproductive technology
Assisted reproductive technology fails to result in a live birth in about two-thirds of cases. In addition, it is more likely to lead to multiple birth than nautral conception. As a result, infats conceived through ART techniques have higher rates of premature birth and other problems
In what ways do genes influence development?
Genetics distinguish between the genotype, which is the pattern of inherited characteristics and the phenotype, which is the reuslt of the interaction of genotype and enviornment. Genes are transmitted from parent to child according to comlex patterns of inheritance that incude dominant/recessive, polygenic, multifactorial and sex linked.
What happens in each of the stages of prenatal development?
During the frist days afect conception, called the germinal stage of development, the zygote( the initioal cell formed by egg and sperm) divides, travels down the fallopian tube and is implanted in the wall of the uterus. The second stage, the period of the embryo, which lasts until 8 weeks after fertilization, includes the development of the vairous structures that support fetal development, such as the placenta, as well as primitive fomrs of all organ systems. The final 30 weeks of gestation, called the fetal period, are devoted primarily to enlargment and refinements in all the organ systems
How do male and female fetusues differ/
Druing the embryonic period, the XY embryo secretes the hormone testosterone, which stimulates the gorwth of male genitalia and sifts the brain into a “male” pattern. Boys are more active, have more slowly developing skeletons, are bigger at birth, and are more vulnerable to most forms of prenatal stress
what behaviors have scientisits observed in fetuses?
the fetus is responsive to stimuli and appear to learn in the womb. Temperamental differences in the womb (Such as activity level) persist infor infacy and childhood, and some aspects of the prental sensory environment may be important to future development
what are the effects of the major dominant, recessive and sex-linked diseases.
Dominant disorders are not usually manifested until adulthood. Huntington’s disease, a fetal affliction of the nervous system, si one such disorder. Recessive disorders affect in dividuals earlier in life, often leading to mental retardation and early death. Theses disorders included phenylketonuria, sickle-cell disease, and Tay-Sachs disease. A fairly comon sex linked disorder is red-green color blindiess. Hemohilia and fragile X syndrome are more serious sex-linked disorders that affect males far more often than females
What techniques are used to assess and treat problems in the prenatal devlopment?
Techniques such as fetoscopy, ultrasonograph, chorionic villus sampling and amnicentessis are used to diagnose chromosomal and gentic disorders, and along with labratory tests identify problems in fetal development. A few such problems can be treated prior to birth with surgery and/or medicaiton
how do trisomies and other disorders of the autosomes and sex crhomosomes afect development?
abnormal nummbers of chromosomes or cromosomal damage cause a number of serious disorders such as Down’s syndrom
How do maternal diseases and environmental hazards affect prenatal development?
Some diseases contracted yb the mother, including rubella, aids, STD, (herpves CMv) and chronic illness may cause abnormalitys or diseae in the child. Environmental hazards include pollutants such as mercury or lead as wel as parasite-bearing substances such as animal fects. Their effect on th efetuses varieswith the tming of the exposure
How was technology changed the way that health professionals manage high-risk oregancies?
Health professionals can closely monitor the conditions of both expectant mothers and fetuses with small devices that women can use or wear as they go about their normal activities
What are the potential advese affects of tabacco, alchohol, and other drugs on prenatal devlopment?
drugs such as alcohol and nicotines appear to ahve harmful effects on the developing fetus; drugs effects depend on the timing of exposure and teh sodosage
what are the risks associated with legal drugs, maternal diet, age, emotional distress and poverty?
some prescriptions and over-the-counter drugs have teratogenic efects. Physians need to know what drugs pregnant women take regularly so that they can provide guidance to the apporpriate use of such during pregnancy. If a mother suffers from poor nutrition, she faces and increase risk of stilbrith, LBW, and infat death during first year of life. Older mothers and very young mothers also run increased risks, as do their infants. Long-term severe depression or chronic phsical illness in the mother may increase the risk of complications during pregnancy or difficulties in the infant. A number of prenatal risk factors are associated with pverty, including earlier age at first pregnancy and lack of access to prenatal care
