Biology

Human Genetics and Disorders

844 Questions

Human Genetics and Disorders covers the inheritance patterns, genetic mutations, and molecular basis of hereditary diseases. Topics include sex-linked traits, cancer genetics, and metabolic disorders. This section tests knowledge critical for biology exams and general science papers.

Genetic mutationsInherited disordersCancer geneticsGenetic testingMendelian inheritance

Human Genetics and Disorders Questions

Multiple choice

At present, scientists can determine the arrangements or relative position of genes of DNA sequences on a chromosome. how does this knowledge benefit us?

  1. It is possible to know the pedigree of livestock.
  2. It is possible to understand the causes of all human diseases.
  3. It is possible to develop disease resistant animal breeds.

Which of the statements given above is/ are correct?

  1. 1 and 2 only

  2. 2 only

  3. 1 and 3 only

  4. 1, 2 and 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Significances of genome sequencing:  It is possible to know the pedigree of livestock, to develop disease-resistant animal breeds, to understand the causes of all human diseases, to do newborn genetic screening.  This will enable the rapidly emerging medical fields of Predictive Medicine and Personalized Medicine and will mark a significant leap forward for the clinical genetic revolution. Full genome sequencing is clearly of great importance for research into the basis of genetic disease.

Multiple choice

A married couple adopted a male child. A few years later, twin boys were born to them. The blood group of the couple is AB positive and O negative. The blood group of the three sons is A positive, B positive, and O positive. The blood group of the adopted son is

  1. O positive

  2. A positive

  3. B positive

  4. Cannot be determined on the basis of the given data.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

AB positive partner forms two type of gametes; A positive and B positive.  O negative partner forms only single type of gamete O negative.  Two type of zygote formation occur A+O- (A positive) and B+O- (B positive). The blood group of the adopted son will be O positive. 

Multiple choice

Which of the following is not correctly matched?

  1. Atherosclerosis: Hardening of the arteries due to deposition of cholesterol

  2. Murmur disorder: A disorder of heart valves.

  3. Sickle cell anaemia: Blood has a defective haemoglobin

  4. Coronary heart disease: Due to insufficient blood supply to the heart muscles

  5. Christmas disease: Haemophilia A
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Christmas disease is also known as haemophilia B.

Multiple choice

Leigh Syndrome is related to which disorder?

  1. Mitochondrial

  2. Reproductive

  3. Hormonal

  4. Cerebral
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mitochondria are an essential organelle in eukaryotic cells. Their function is to convert the potential energy of glucose, amino acids, and fatty acids into adenosine triphosphate (ATP) in a process called oxidative phosphorylation. Mitochondria carry their own DNA, called mitochondrial DNA (mtDNA). Between 20 and 25 percent of Leigh syndrome cases are caused by mutations in mitochondrial DNA.

Multiple choice

Which form of retardation can be controlled by a special diet?

  1. microcephaly

  2. hydrocephaly

  3. PKU

  4. down syndrome
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Phenylketonuria (PKU) is a metabolic disorder that causes intellectual disability if left untreated, but it can be managed by strictly following a special diet low in phenylalanine.

Multiple choice

Regarding the Zone Strata Theory of Taylor, which one of the following statements is not correct ?

  1. Central Asia has been the cradle land of human races.

  2. Oldest human races are farthest away from the cradle land.

  3. Recent human races are nearest to the cradle land.

  4. Caucasoids are the latest human races.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Griffith Taylor's Zone and Strata theory posits that the most primitive races were pushed to the peripheries by later, more advanced races. The theory does not claim Caucasoids are the latest human races; rather, it suggests the most recent races are found near the center of origin.

Multiple choice

Norwegian scientists have determined Rudolph's nose is red because ...

  1. They couldn't figure it out, so they say it's magic. Duh.

  2. He was actually born that way; it's a birthmark.

  3. It's a parasitic infection of his respiratory system.

  4. Santa fed him a special diet of only red foods.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A tongue-in-cheek study by researchers in Norway suggested that Rudolph's nose is red due to a parasitic infection of his respiratory system, which causes high blood flow to the area. This is a humorous scientific take on the myth.

Multiple choice

Which of the following is not inherited?

  1. hitchhiker's thumb

  2. atached or detached earlobes

  3. being physically fit

  4. being able to roll your tongue
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Inherited traits are passed down through genes from parents. Being physically fit is a result of lifestyle, exercise, and diet, not genetic inheritance.

Multiple choice botany classical genetics non mendelian inheritance deviation from mendelism genetics

Inheritance of blood group is a condition of
1. Co-dominance
2. Incomplete dominance
3. Multiple allelism
4. Multiple gene

  1. 1, 2

  2. 2, 4

  3. 2, 3

  4. 1, 4

  5. 1, 3
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Incomplete dominance is the condition when the dominant allele is not completely dominant over the recessive resulting in a mixture of dominant-recessive phenotype in heterozygous condition. When a single trait is governed by more than one gene, it is said to be under control of multiple genes. Human blood group inheritance is the example of codominance and multiple alleles. It is governed by three alleles of gene "I", namely I$^{A}$, I$^{B}$ and I$^{O}$. I$^{A}$ and I$^{B}$ show codominance while allele "I$^{O}$" is recessive to both "I$^{A}$" and "I$^{B}$". This gives total six genotypes and four phenotypes : A (I$^{A}$ I$^{A}$ and I$^{A}$ I$^{O}$), B (I$^{B}$ I$^{B}$ and I$^{B}$ I$^{O}$) , AB (I$^{A}$ I$^{B}$) and O (I$^{O}$ I$^{O}$). Correct option is "E".