Human Genetics and Genetic Disorders

It is possible to correspond enzyme activity with a specific chromosome in a somatic cell hybrid.

Deliberate crosses are not used in studying the inheritance patterns of human beings.

All the female eggs will have X chromosome with the white-eye mutation while the sperm will posses either a normal X chromosome or a Y chromosome. By using Punnett square, we can predict the outcome of this cross. Female progenies will receive X chromosome from both the sperm and egg cells. All females receive the dominant, red-eyed allele from their fathers and the recessive, white-eyed allele from their mothers.

The pure breed female is homozygous with the normal X chromosome and the white-eyed male is hemizygous for the X chromosome with a white eye mutation. Therefore, all male and female progenies are red-eyed.

It must be recessive because both parents are normal, but one or both parents must have passed the disease allele to their daughter. Since one or both parents are heterozygous and are not affected by the Tay-Sachs allele, the disease must be recessive.

As per the question, all of the females are red-eyed and heterozygous. All of the males are white-eyed and hemizygous.

Human males are termed as hemizygous for any X-chromosome genes, meaning that there are only half (hemi) as many alleles as normally present for a diploid individual. As a result, if males inherit X-linked recessive trait from their mothers, they will show the recessive phenotype.

Genes and anonymous DNA markers located near each other on the same chromosome are linked and do not segregate independently during meiosis.

A karyotype is used to demonstrate the number, types and appearance of chromosomes. Analysis of chromosomes of the developing foetus can be carried out with cells obtained from the amniotic fluid within the mother's uterus.

A karyotype is used to show the number, types and appearance of chromosomes. Therefore, an extra X chromosome in a Klinefelter's person could be readily diagnosed by karyotyping.

All statements are correct.

It is the true statement because in humans the sex is determined by the sex chromosome in the sperm that fertilizes the female egg. Half of the sperm have a X-chromosome and half have a Y-chromosome.

One of the two X chromosomes in female somatic cells is foreseed as a densely staining body within the nucleus known as Barr body.

This condition arises due to nondisjunction or loss of a structurally abnormal X or Y chromosome. Many are mosaics, with a cell line containing 46 chromosomes with a structurally abnormal X or Y.

All are useful tokens for genetic or physical mapping of human chromosomes.

Since this genetic trait has been passed from generation to generation from both fathers to daughters and mothers to daughters, therefore it is typically autosomal dominant trait.

Newly born are hypotonic at birth and may have congenital anomalies, especially cardiac and gastrointestinal. Facial features include flat occiput, up-slanting palpebral fissures, furrowed tongue, short fingers and toes, and incurved fifth finger. 

It results from the microdeletion of chromosome 22q11.2. Usually it is not visible cytogenetically, but detectable by FISH or comparative genomic hybridization.

The autosomal dominant gene leading to Huntington's disease has a mutation due to the extension of a triplet sequence of (CAG) within the coding region of the gene. Since the arrangement of the entire gene is now known, primers on either side of the tandem repeat arrangement of (CAG)n can be used to modify the region using the polymerase chain reaction and determine the size, i.e. number of times CAG is repeated. The triplet repeat arrangement is known as a STRPs, or short tandem repeat polymorphisms. <span style="line-height:" 16px;="">

It is an autosomal dominant disease. It arises due to the mutation in the TP53 tumor suppressor gene. Its symptom includes cancers involving multiple sites including soft tissue sarcoma, osteosarcoma, etc.

It is a X-linked dominant disease. It results from the loss of function mutation of IKBKG gene. Primarily affects females and is lethal to hemizygous males in utero.

It is an autosomal recessive disease. It results from the mutation in SERPINA1 gene, which encodes α1-antitrypsin, a protease inhibitor. Lack of α1-antitrypsin in the lung leads to pulmonary damage due to inflammation.

It is an autosomal dominant disease. It results from the mutation in NF1 gene on chromosome 17. It is associated with development of tumors of the nerve sheath. Other features of NF1 include café-au-lait spots, optic glioma, learning disability, and increased risk of malignancy or vascular disease.

People with Bloom syndrome have low birth weight and proportionate short stature as they grow. There are distinctive facies, with underdeveloped malar bones and a sun-sensitive rash appears on the face, hands, and forearms.

Alzheimer disease is associated with memory loss and confusion, and may include language problems, poor judgment, agitation, and hallucinations. Brain atrophy is seen by MRI. There are no physical signs of the disease.