A boy with Down syndrome (trisomy 21) has 46 chromosomes. One parent and his two older sisters have a normal phenotype, but each have 45 chromosomes. a)Explain how this is possible. b)How many chromosomes do you expect to see in karyotypes of the parents? c)What term best describes this kind of chromosome abnormality? d)What is the probability the next child of this couple will have a normal phenotype and have 46 chromosomes?  Explain your answer.

Q: For the following chromosome complements, what is the phenotypic sex of a person who has Q. XXYY…

A: The male-determining gene in humans is termed as the sex determining region Y (SRY) gene. Generally…

Q: What is meant by the termhomologous chromosomes?

A: Chromosomes are filamentous bodies present in the nucleus. They are composed of DNA(…

Q: How many genes are there present on chromosome 13 ?

A: Chromosomes are the carrier of genetic material deoxyribonucleic acid (DNA). They are coiled in…

Q: What are the designations of the sex chromosomes in males of bugs, humans, and butterflies?

A: Chromosomal determination of sex It is also known as allosomic determinati9on of sex and is based on…

Q: If a dog cell (2n = 78) enters meiosis, how many chromosomes will be present in each daughter cell…

A: In Meiosis process , two divisions are involved that are Meiosis 1 and Meiosis 2.

Q: What unusual feature of the Y chromosome allows some recombination among the genes found on it?

A: Every individual has 23 pairs of chromosomes, out of which 22 are identical, one ie sex chromosome…

Q: Explain how an individual can have Down's Syndrome, and a karyotype that reveals 46 chromosomes.…

A: A genetic disorder is a condition that is caused in whole or in part by a deviation from the…

Q: A phenotypically abnormal individual has a phenotypically normalfather with an inversion on one copy…

A:

Q: What causes chromosomal rearrangements?

A: Chromosomes carry the genetic material DNA. Gene is a segment of DNA. The necessary information for…

Q: Why is the incidence of survivable genetic disorders involving deletions of parts of chromosomes so…

A: Deletions are the genetic aberrations or mutations in which a sequence of DNA or a segment of a…

Q: If a diploid cell entering meiosis has 12 chromosome pairs, what is the number of possible…

A: Meiosis is a process of cell division, where cell divides twice to produce four daughter cells which…

Q: Which of the karyotypes shown is from a normal female?

A: A karyotype represents all the 23 pairs of chromosomes in a picturized form. It provides information…

Q: Why is the word homologous used to describe chromosome pairs, rather than the word identical?

A: Homologous chromosomes are the chromosomes that is acquired one from the paternal and another from…

Q: Which one cannot be a reason for chromosome disjunction anomaly?

A: Disjunction anomaly  When the chromosomes of a cell unable to separate and each daughter cells got…

Q: What is meant by the term diploid? Which cells of the humanbody are diploid, and which cells are…

A: The ploidy term refers to the number of sets of the chromosomes. The euploidy refers to the…

Q: How many genes are there present on chromosome 12 ?

A: Chromosomes are thread-like structure, which are composed of nucleic acids and protein. They are…

Q: What is the chromosome abnormality in cri du chat syndrome?

A: Cri-du-chat syndrome, commonly known as 5p- (5p minus) syndrome. Infants with this syndrome…

Q: Draw and describe FIVE (5) types of chromosome structural changes

A: After the birth or during the fetal development of zygote or during spermatogenesis or oogenesis…

Q: How many genes are there on chromosome 6?

A: In all the living organisms, the genetic material is organized into a specific structure known as a…

Q: name the Extrachromosomal elements?

A: Chromosomes are thread-like structure, which are composed of deoxyribonucleic acid (DNA) and…

Q: what criteria or features are used to identify each chromosome by number?

A: The basis of cytogenetics is laid on the study of chromosomes. The isolation and identification of…

Q: what is the significance of chromosomal aberration? what are the different types of chromosomal…

A: Chromosome contains the genetic information of the organism.

Q: How does a chromosomal duplication occur?

A: When a part of chromosome is present in two copies or duplicated, it is known as duplication. This…

Q: half the chromosomes of a human primary oocyte segregate into the first polar body, which…

A: The process of formation of gametes is different in males and females. In males, it is known as…

Q: . In a diploid organism of 2n = 10, assume that you canlabel all the centromeres derived from its…

A: The formula that is used for the solution of this problem is 2n. Here, n stands for the different…

Q: Non-disjunction of chromosome 21 during meiosis one followed by fertilization can result in all of…

A: An zygote with nondisjunction has 3 duplicates of chromosome 21 rather than the usual two. A pair of…

Q: What are the possible effects of chromosomal rearrangements?

A: In genetics, a chromosomal rearrangement or Any alternation in the sequence of nucleotide in the…

Q: How many genes are there present on chromosome 21 ?

A: Chromosomes are thread-like structures that are located in the nucleus. It is composed of protein…

Q: What are chromosomal islands? Why are theyconsidered to be of foreign origin?

A: Chromosomes are long thread-like structures that carry coded genetic information in the form of DNA.…

Q: Trisomy 18 (Edwards Syndrome) is identified by a karyotype that shows A. too few copies of…

A: The normal number of chromosomes present in homo sapiens, I.e Human Beings is 46( 44 autosomes (22…

Q: How many chromatids are present for each type of chromosome at the completion of crossing over? What…

A: Crossing over is the process in genetics by which the two chromosomes of a homologous pair exchange…

Q: How many genes are there present on chromosome 23 ?

A: Chromosomes are the carrier of genetic material deoxyribonucleic acid (DNA). They are coiled in…

Q: For the following chromosome complements, what is the phenotypic sex of a person who has Q. XXY with…

A: A gene is a unit of genetic material present within the DNA (deoxyribonucleic acid). Each gene…

Q: Which of the karyotypes shown is from a normal female?

A: Karyotyping is the process of taking micro pictures of human chromosomes to understand their nature…

Q: Why is chromosome 21 the smallest and not chromosome 22? considering that a karyogram is arranged…

A: Introduction: In the nucleus of each cell, the DNA molecule is bundled into thread-like structures…

Q: What is chromosomal mapping?

A: A chromosome contains all of the genetic material of an organism. Almost all the eukaryotic…

Q: In a diploid organism of 2n=10, assume that you can label all the centromeres derived from its…

A: Meiosis creates gametes such as egg and sperm cells. During meiosis, the genetic information is…

Q: What is heterozygous variant?

A: The term heterozygous variant belongs to a subdivision of biology, genetics. Genetics is the study…

Q: For the following chromosome complements, what is the phenotypic sex of a person who has Q. XY with…

A: The male sex-determining gene in humans is termed as the sex determining region Y (SRY) gene.…

Q: What is the difference between polygeny and pleiotropy?

A: Biological inheritance, also called heredity, is the process by which different traits are passed on…

Q: Is this karyotype a male or female? Which chromosome is the longest and has the most genes?  Which…

A: Introduction Chromosomal studies, also known as karyotyping, is a test that assesses a person's…

Q: An individual that is heterozygous for an inversion has the following chromosomes (∗ is the…

A: Introduction :-  Crossing over is defined as the exchange of segments ( chromosomal segments)…

Q: What is the nucleous for?

A: Given : The nucleolus for.

Q: What criteria or features are used to identify each chromosome by number?

A: *NOTE: Kindly repost for other question. Dear Student as per the guidelines we are supposed to…

Q: based on fig 1. Is this karyotype a male or female? Is there a chromosomal disorder? What type of…

A: Karyotype --  is complete collection of chromosomes of a person it may be a male or female karyotype…

Q: What is a crossing over, and what is the purpose of it?

A: The cell cycle is the orderly series of events allowing a cell to grow and divide forming daughter…

Q: From 2 to 6 percent of people with autism have an extra chromosome that consists of two long arms of…

A: Isodicentric 15 It is also called idic15 and inverted duplication 15. It is an chromosome…

Inheritance and Mendelian Genetics

Inheritance means the passing of traits to offspring from parents. These traits could be passed either through asexual reproduction or sexual reproduction. The offspring receives the genetic material from the parents. Mendelian inheritance is a certain biological inheritance that follows the rules and principles laid down by Gregor Mendel in 1865. The initial hypothesis was considered wrong, but other inheritance theories modified the concept of inheritance and thus genetics.