Failure of cytokinesis after telophase stage of cell divislon results in an increase in a whole set of chromosomes in an organism and, this phenomenon is known as:
1. Aneuploidy
2. Translocation
3. Polyploidy.
4. Inversion
Which of the following is not a feature of Down's Syndrome?
1. It is caused by a non-disjunction in an autosome
2. The affected individual has trisomy of chromosome 21
3. The aflected individual has a characteristic simian palmar crease
4. The mental development of affected individual is normal
Identify the incorrect statement:
(1) In addition to recombination, mutation is another phenomeonon that leads to variation in DNA.
(2) Chromosomal aberrations are commonly observed in cancer cells.
(3) A classical example of a point mutation is sickle cell anaemia.
(4) Non ionising radiations cannot be mutations.
Pedigree analysis is resorted to for genetic analysis in humans rather than conventional genetic methods because:
I. Choice matings are not possible
II. Number of progeny is limited
Of the two statements:
(1) Only I is correct
(2) Only II is correct
(3) Both I and II are correct
(4) Both I and II are incorrect
Match each item in Column I with one item in Column II and chose your answer from the codes given below:
Column I Disorder |
Column II Feature |
I. Phenylketonuria II. Sickle Cell anemia III. Down's Syndrome IV. Turner's Syndrome |
(i) Rudimentary ovaries (ii) Gynecomastia (iii) Trisomy 21 (iv) Lack of enzyme PAH (v) Lack of tyrosinase (vi) Mutation GAG to GUG (vii) Mutation GUG to GAG |
1. I - v; II - vii; III - iii; IV - i
2. I - iv; II - vi; III - iii; IV - i
3. I - v; II - vi; III - iii; IV - ii
4. I - v; II - vi; III - iii; IV - i
In a monohybrid cross F1 progeny resemble neither of the parents. What would be true in this case?
1. The parental traits would not appear in any of the F2 -progenies
2. The F2 phenotypic ratio will be different from the F2 genotypic ratio
3. It could be a case of incomplete dominance
4. The F2 phenotypic ratio will be similar to any Mendelian monohybrid cross
The two alleles of a gene pair are located on:
1. Homologous sites on homologous chromosomes
2. Heterologous sites on homologous chromosomes
3. Homologous sites on heterologous chromosomes
4. Heterologous sites on heretologous chromosomes
Male heterogamety is not seen in:
1. Humans
2. Melandrium album
3. Birds
4. Fruit fly
The trait shown in the given pedigree chart is most likely a/an:
1. Autosomal recessive trait
2. Autosomal dominant trait
3. Sex linked recessive trait
4. Sex linked dominant trait
Aneuploidy results from :
1. Point mutations
2. Gross structural changes in chromosomes
3. Failure of cytokinesis after telophase stage of cell division
4. Failure of segregation of chromatids during cell division