A phenotypically normal boy has 45 chromosomes, but his sister, who has Down syndrome, has 46. Suggest an explanation that explains both children.

Q: an human is born with 45 chromosomes, what type of mutation occurred within this individual?

A: Human beings have 22 pairs of autosomal chromosomes and 1 pair of sexual chromosomes. Autosomes…

Q: Trisomy 21, or Down syndrome, occurs when there is a normal diploid chromosomal complement but one…

A: Down's syndrome occurs due to an error at the time of gamete formation. As a result the gametes may…

Q: Could there be any significance to the fact that the crosses concern genes on a very small…

A: DNA is the genetic material in most living organisms. It is the information hub of the cell that…

Q: Familial Down syndrome is similar to primary Down syndrome in that it is caused by trisomy 21.…

A: Two normal copies of 14, two normal copies of 21: A.Two normal copies of 21, one normal copy of 14:…

Q: In humans, chromosome 16 sometimes has a heavily stained area in the long arm near the centromere.…

A: Nondisjunction means failure of pair of homologus chromosome to separate or segregate either during…

Q: What does an extra chromosome 16 mean?

A: Chromosomes, the physical carriers of genes, are the microscopic thread like structures in which the…

Q: In humans, chromosome 16 sometimes has a heavily stained area near the centromere. This feature can…

A: So, non disjunction of the chromosomes occurs in the condition when the homologous chromosomes fail…

Q: explain why telomeres at the end our chromosomes shrink as we grow older.

A: Telomere  End of chromosome made up of repetitive non coding DNA.

Q: I have a doubt, I'm not sure if the chromosomes are a boy or a girl? Or if the chromosomes have any…

A: Monosomy is an aneuploidy in which only one of a pair of chromosomes is present. When a section of…

Q: Mules result from a cross between a horse (2 n = 64) and a donkey (2 n = 62), have 63 chromosomes,…

A: Meiosis is the process through which gametes are formed. It includes a reduction in the number of…

Q: Why is the term “crossing-over” appropriate for the exchange of DNA segments between homologous…

A: Crossing over can be defined as the exchange of genetic material that occurs between the non-sister…

Q: What is the type of inheritance? What is known of the genotype of the male in the above cross? What…

A: Introduction  Genetics is frequently used to refer to heredity, which is the passing on of genetic…

Q: Raj Kumar and his wife Sunita have been blessed with a baby girl. On the other hand, Kripa Shanker…

A: Reproduction ensures the continuity of species on earth. It can occur in two ways that is sexual…

Q: Hemophilia results from a sex-linked gene. The disease is most common in males, but the hemophilia…

A:

Q: Some people compare a homologous pair of chromosomes to a pair of shoes. Explain the similarity. How…

A: Homologous pairs of the chromosome are those chromosomes which have the same type of structure and…

Q: Referring to Figure 17-19, draw a diagram showing the process whereby an inversion formed from…

A: An inversion is a type of chromosomal rearrangement in which a chromosomal segment is reversed end…

Q: Explain why genes located on the same chromosome are said to be linked. Why do alleles of linked…

A: A gene is a unit of hereditary arranged in thousands on the strands of DNA(deoxyribonucleic acid)…

Q: Person A has a mutation in a chromosome in a liver cell, while person B has a mutation in a…

A: Mutation refers to sudden heritable change in the phenotype of an individual. In the molecular term,…

Q: Consider the example of the fusion of chromosome 21 and 14. By itself, this fusion does not cause…

A: In humans, when the long arm of chromosome 21 is joined to the long arm of chromosomes 14 or 15, the…

Q: You are a gene hunter, trying to find the genetic basis for a rare inherited disease. Examination of…

A: It is given that the rare inherited disease is co-inherited with the markers on the chromosome 7 for…

Q: karyotype is an important clinical method for diagnosing genetic disorders. Explain why it is useful…

A: A karyotype can be defined as a photograph of total chromosomes in a human body. It can be also said…

Q: why why heterozygosity for a deletion can be harmful?

A: Deletion refers to a type of mutation in which the genetic material in a chromosome is deleted or…

Q: Fetuses whose cells are triploid, that is, contain three full sets of chromosomes, develop to term…

A: INTRODUCTION The DNA molecule is packed into thread-like structures called chromosomes in the…

Q: hromosomes only pair during meiosis. Why is this pairing

A: Cell division is defined as the process by which cells multiply and involve nuclear as well as…

Q: A meiotic-nondisjunction causes trisomy 8 in a newborn.  If two of the three copies of chromosome 8…

A: When the homologous chromosomes fail to separate during the meiosis I stage, this will result in…

Q: Why is random assortment of chromosomes necessary? What can we expect if this does not occur?

A: When reproductive cells mature, the Principle of Independent Assortment outlines how various genes…

Q: The Klinefelter syndrome (disomy of the X chromosome in males) is a genetic disease caused by…

A: The normal humans contain 46 chromosomes. Between these 46 chromosomes, 44 are autosomes and 2 are…

Q: During the pathoanatomic inspection of a baby-boy's dead body the following abnormalities:…

A: Chromosomal disorder are the abnormalities that arises due to alterations in chromosome arrangement…

Q: Explain the reason why a dicentric chromosome is unstable.

A: Chromosomes having two centromeres are said to be dicentric. The centromeres on chromosomes…

Q: A woman with no phenotype is known to have a 14:21 translocation. Please answer questions 1 and 2.…

A: Between two acrocentric chromosomes where the centromere is at one end of the…

Q: You are transported to a fantasy world where legendary creatures actually exist. In this world, a…

A: Unicorn is a bisexual horse with a single straight horn projecting from its forehead. It is…

Q: Karl and Hally Sax crossed Aegilops cylindrica (2 n = 28), a wild grass found in the Mediterranean…

A: Karl and Hally Sax conducted a cross between Aegilops cylindrical (2n = 28) and Tridcum vulgare (2n…

Q: Briefly explain why, in humans and other mammals, sex-chromosome aneuploidies are more common than…

A: A chromosome is an organized bundle of DNA found within the nucleus of the cell. Different living…

Q: Homologous chromosomes can be either monads or dyads. Explain. How is it possible to have…

A: Homologous chromosomes are paired chromosomes. In this pair one chromosome comes from mother and one…

Mitochondrial Mutations

A mitochondrion is a cellular organelle that serves as the site for cellular respiration and energy production (ATP or Adenosine Triphosphate). It is a double-membrane-bound organelle and is only present in eukaryotic cells.