Chapter 9- Possible short answer questions

What is amniocentesis?

Amniocentesis is type of lab test to diagnose birth defects during prenatal development. Samples are withdrawn from the amniotic fluid and subjected to testing the components of the fluid

What is Cystic Fibrosis? Mention at least two symptoms of it.

CF-causes mucus to build up and clog the lungs and make breathing very difficult. Symptoms includes salty-tasting skin, coughing, bronchitis, shortness of breath, poor growth/weight gain in spite of a good appetite, frequent greasy, bulky stools

Why color blindness/hemophilia are mostly seen in males?

Color blindness is a X-linked dominant genetic mutation. Females (XX) have a back up copy of the associated with the trait whereas males (XY) receive only one of copy of this dominant trait thus always express the phenotype

What is Fetal Alcohol Syndrome? Specify the phenotypes of this birth defect.

FAS are collective abnormalities caused due to maternal exposure to alcohol. It is characterized with facial phenotypes including facial abnormalities, delayed growth, malfunction of different organs including heart.

What is Sickle cell anemia? Describe its symptoms.

Genetically inherited disorder resulting in sickle shaped RBC in blood affecting the oxygen carrying ability to the body. This disease is common with African races a sa trait evolved in fighting against the malarial parasite. Symptoms include painful swelling of the hands or feet or both, whites of the eye appear yellow, tongue/lips/palms appear paler. When sickled clog the blood vessels cause pain and disrupts essential functions of various organs.

Which teratogen causes cancer in childhood?

all types of radiation. Eg. exposure to X-rays

What causes Twin-to-twin syndrome?

One twin takes nourishment from the other causing abnormalities in the affected offspring, this is generally caused by fertility drugs

Describe the effect of Maternal Rubella on Birth Defects?

Rubella infection generally occurs during the 1st trimester and can cause blindness, deafness, heart disease and retardation in babies.

Define birth defect

is an abnormality of structure, function, or metabolism, whether genetically determined or the result of environmental interference during embryonic or fetal life.

Mention atleast two birth defects related to nutrition and briefly explain the phenotypes related to them

• Acrocephalosyndactyly: caused by maternal metabolic imbalance characterized by premature suture closure resulting in abnormal head shape and webbed digits • Anencephaly: is the absence of a major portion of skull, brain and scalp

Mention an example of condition caused Toxoplasmosis. Explain the abnormalities associated with the disease and the treatment available to encounter the condition.

Hydrocephaly: Cerebrospinal Fluid (CSF) that is normally produced by the ventricles of the brain and exists between the brain and the meninges that surrounds it. CSF aids to protect the brain and spinal cord and acts as a shock absorber. It also carries away disposed materials. CSF normally gets drained into the blood stream. In the individual with hydrocephalus, the fluid does not drain away properly, but accumulates. In an infant, the seams of the skull have not yet fused, so the skull gets bigger as the fluid accumulates. This baby recovers after having surgery to install a shunt to drain the fluid artificially.

Differentiate miscarriage and still birth.

If the baby dies before the 20th week it is called a miscarriage. If the baby dies after that time, it is called a stillbirth. Most of these defects occur during zygote formation and early embryogenesis.

Mention three causes of prenatal damage.

Infections, Drugs, Maternal disorders such as diabetes, High blood pressure, Rh disease, Umbilical cord accidents, Difficult labor or delivery, Premature birth

What is Marfan's syndrome?

Marfan's syndrome is a disorder of connective tissue that causes skeletal defects typically recognized in a tall, lanky person. A person with Marfan's syndrome may exhibit long limbs and spider-like fingers, chest abnormalities (inversion of the septum), curvature of the spine and a particular set of facial features including a highly arched palate, and crowded, crooked teeth

What are teratogens? Give two examples of teratogens

Teratogens are environmental agents that interfere with embryonic or fetal development causing birth defct or abnormalities. Eg. Nicotine, caffeine, radiations, drugs, chemicals

Discuss about the influence of dominant and recessive alleles on birth defects.

The gene that can express its trait even when one copy of allele is present is called as dominant allele, so the trait is generally inherited from one parent. Recessive genes needs both the copies to be present to express the character associated with it, so to pass on the recessive trait alleles are inherited from both the parents. As dominant gene traits are stronger than the recessive traits, the possibility of inheriting the birth defects is more (3/4) whereas the recessive genes inherited are mostly silenced by the dominant gene and the individual remains as a silent carrier of the genetic abnormalities.

What is chorionic villi sampling?

This is an advanced diagnostic technique to identify birth defects prenatally; tissue samples from the embryonic region of placenta-the chorionic villi will be collected for testing in lab

What is Toxoplasmosis? Explain the abnormalities caused by this.

Toxoplasmosis, a parasite in cat litter and some raw meat, can cause blindness, hearing loss, learning disabilities and death. Toxoplasmosis can cause miscarriage, still birth, eye and brain damage caused by constant exposure to cats.

Which technique is used for determining the structural morphology of the developing offspring?

Ultrasound technique help to determine the structure of skeletal, circulatory and nervous systems

Name birth defects caused by maternal exposure to disease or infection during pregnancy

Varicella, Rubella, Toxoplasmosis and all of the STDs