Karyotyping is a technique that is most useful for diagnosing which type of genetic disorder?
Karyotyping involves arranging the chromosomes of a cell based on size and structure, allowing for the easy detection of abnormal chromosome numbers (aneuploidy) or structural changes.
Question 152 of 519
📘 CLASS XII
If the mother's blood group is B (heterozygous IBi) and the father's blood group is A (heterozygous IAi), what is the probability of having an offspring with Blood Group AB?
The cross IAi × IBi yields: IAIB (AB), IAi (A), IBi (B), and i i (O). The probability of IAIB (AB) is 1 out of 4, or 1/4.
Question 153 of 519
📘 CLASS XII
A child with Turner's syndrome has how many autosomes?
A normal human has 22 pairs of autosomes (44 total) and one pair of sex chromosomes (XX or XY). Turner's syndrome is 45,X, meaning 44 autosomes and only one X sex chromosome.
Question 154 of 519
📘 CLASS XII
What is the full karyotype of a male with Klinefelter’s syndrome?
Klinefelter’s syndrome is characterized by 47 chromosomes, including an extra X in a male: 47,XXY.
Question 155 of 519
📘 CLASS XII
The two autosomal genetic disorders mentioned in the text are the result of:
The text specifically mentions Down’s syndrome (Trisomy 21), Turner’s syndrome (XO), and Klinefelter’s syndrome (XXY) as being due to change in a subset of chromosome number (aneuploidy). Down's is the autosomal example of aneuploidy among the listed disorders.
Question 156 of 519
📘 CLASS XII
Which stage of meiosis is most prone to the non-disjunction event that causes aneuploidy?
Non-disjunction is the failure of homologous chromosomes to separate during Anaphase I, or the failure of sister chromatids to separate during Anaphase II.
Question 157 of 519
📘 CLASS XII
In the study of pedigree analysis, a square symbol usually represents:
In standard pedigree charts, circles represent females, and squares represent males.
Question 158 of 519
📘 CLASS XII
The total chromosome count for an individual with Turner's syndrome is:
Turner's syndrome is 45,X, meaning there is one fewer sex chromosome than normal (46 − 1 = 45).
Question 159 of 519
📘 CLASS XII
If an autosomal recessive disorder is tracked via pedigree, how would two unaffected parents transmit the trait to their offspring?
In an autosomal recessive disorder, unaffected parents can only have an affected child if both are heterozygous carriers (Aa × Aa), resulting in a 25% chance of an affected homozygous recessive (aa) child.
Question 160 of 519
📘 CLASS XII
What is a 'point mutation'?
A point mutation is a small-scale mutation involving a change in just one base pair in the DNA sequence.
