Tag: pleiotropy

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Questions Related to pleiotropy

Multiple choice pleiotropy genetics zoology

Teacher asks the student to give the best example to explain pleiotropy. The correct answer is

  1. Flower colour in snapdragon

  2. Seed coat colour of garden pea

  3. ABO blood group system of human

  4. Phenylketonuria
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pleiotropy occurs when one gene will code and control the phenotype or expression of several different and unrelated traits. Phenylketonuria is an autosomal recessive disorder controlled by a mutant gene present on the 12th chromosome. This mutant gene fails to code for the enzyme phenylalanine hydroxylase required for normal metabolism of amino acid phenylalanine to tyrosine. Due to this, there is an accumulation of phenylalanine in body fluids such as blood, sweat, CSF. An abnormal breakdown product phenyl ketone is found in urine A higher level of phenylalanine and pheylketone cause severe brain damage leading to mental retardation. Thus phenylketonuria is the best example to explain pleiotropy.

So, the correct answer is 'Phenylketonuria'

Multiple choice pleiotropy genetics zoology

A pleiotropic in Drosophila is that of

  1. Red-white eye

  2. Bar eye

  3. Vestigial gene

  4. Forked bristles.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In Drosophila, the vestigial gene is a classic example of pleiotropy, affecting not only wing size but also haltere size, bristle orientation, and reproductive fitness.

Multiple choice pleiotropy genetics zoology

A $15: 1F _2 $ ratio of a cross between a wheat variety with red kernels (homozygous for two dominant genes) and another with white kernels shows 

  1. Polygenic inheritance

  2. That the two genes are complementary

  3. Single factor inheritance

  4. That it is a tes cross
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

E.Nilsson – Ehle crossed red kernelled variety with white kernelled variety of wheat. The grains of F1 were self crossed among themselves, five different phenotypic classes appeared in F2 showing the ratio of 1:6:15:20:15:6:1.

These scientist found that the kernel colour in wheat is determined by two pairs of genes A and B. It is called polygenic inheritance.

So, the correct option is ‘polygenic inheritance’.

Multiple choice pleiotropy genetics zoology

A pleiotropic gene in humans is

  1. Marfan's syndrome

  2. Colour blindness

  3. Eye colour

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

Mutations in the human gene for fibrillin-1 (FBN1) in the Marfan syndrome and related disorders. Mutations in FBN1 produce Marfan syndrome, a pleiotropic autosomal dominant connective tissue disorder with prominent manifestations in the skeleton, eye and cardiovascular system.

So, the correct information is 'Marfan's syndrome.'

Multiple choice pleiotropy genetics zoology

Occasionally, a single gene may express more than one effect. The phenomenon is called

  1. multiple allelism

  2. mosaicism

  3. pleiotropy

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

When there are three or more alternative forms of a gene, it is called multiple allelism. Polygeny suggests that humans evolved from several different ancestors. When a single gene has more than one effects, it is called pleiotropy.

So, option C is the correct answer.

Multiple choice pleiotropy genetics zoology

In garden pea, gene controlling starch synthesis related to all of the given phenomenon, except

  1. Pleiotropy

  2. Incomplete dominance

  3. Codominance

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

Pleiotropy occurs when one gene influences two or more unrelated phenotypic traits. So, pleitrophy cannot play a role in gene controlling starch synthesis.

Multiple choice pleiotropy genetics zoology

Which of the following is not a pleiotropic gene?

  1. Starch branching enzyme coding gene

  2. Flower colour gene of Pisum sativum

  3. Leaf colour gene of snapdragon

  4. I gene of Blood group
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice pleiotropy genetics zoology

When one gene is responsible for affecting more than one characteristics, the phenomenon is known as

  1. Epistasis

  2. Dominance

  3. Segregation

  4. Pleiotropy

  5. Independent assortment
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Though Mendel through his experiments showcased inheritance of a trait as genetic, some traits results from the combined effect of more than one pair of genes. Contrary to this, a single gene may also be responsible for a variety of traits. This phenomenon is called pleiotropy.

Multiple choice pleiotropy genetics zoology

A gene that shows its effect on more than one character is

  1. Polygene

  2. Pleiotropic gene

  3. Multifactor gene

  4. Multiple gene.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The ability of a gene to produce more than one phenotype in an organism is called Pleoitrophy and the genes are called Pleiotripic genes. It is not essential that the traits are equally influenced. Sometimes, the effect of the gene is more evident in case of one trait and less evident in case of another trait.

So, the correct option is ‘Pleiotropic gene’.

Multiple choice pleiotropy genetics zoology

Same gene loci on two homologous chromosomes produce different phenotypes. They bear

  1. Homozygous alleles

  2. Heterozygous alleles

  3. Two different genes

  4. Pleiotropic genes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The ability of a gene to have multiple phenotypic effects is known as pleiotropy and the genes are called Pleiotropic genes. These genes influence the number of characters simultaneously. These genes are present on same loci on two homologous chromosomes and produce different phenotypes.

So, the correct option is ‘Pleiotropic genes’.