Principles of Inheritance and Variation · Question 167

AIPMT 2000MCQEasy📈 Topic in 50% papers+4−1

Erythroblastosis foetalis is caused when:

Rh- female & Rh+ male
Rh- female & Rh- male
Rh+ female & Rh+ male
Rh+ female & Rh- male

Answer

(1) Rh- female & Rh+ male

Solution

As per NCERT, Rh incompatibility arises when the mother is Rh- and the foetus is Rh+; the foetus can be Rh+ only when the father is Rh+.

In the first pregnancy the mother gets exposed to the foetal Rh antigens at delivery and forms anti-Rh antibodies.

∴ In a later pregnancy these antibodies cross the placenta into the Rh+ foetus and destroy its RBCs ⇒ erythroblastosis foetalis (severe anaemia and jaundice).

Answer: (1)

AIPMT 2000

Keep practising — Principles of Inheritance and Variation

In Drosophila the XXY condition leads to femaleness whereas in human beings the same condition leads to Klinefelter's syndrome in male. It proves:

Y chromosome is active in sex determination in both human beings and Drosophila
In Drosophila Y-chromosome decides femaleness
Y chromosome of man have genes for syndrome
In human beings Y chromosome is active in sex determination

AIPMT 2000

All Principles of Inheritance and Variation PYQs →

PDFDownload Principles of Inheritance and Variation PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇

All NEET Botany chapters

Class 11The Living World Biological Classification Plant Kingdom Morphology of Flowering Plants Anatomy of Flowering Plants Cell: The Unit of Life Cell Cycle and Cell Division Transport in Plants Mineral Nutrition Photosynthesis in Higher Plants Respiration in Plants Plant Growth and Development

Class 12Reproduction in Organisms Sexual Reproduction in Flowering Plants Principles of Inheritance and Variation Molecular Basis of Inheritance Strategies for Enhancement in Food Production Microbes in Human Welfare Organisms and Populations Ecosystem Biodiversity and Conservation Environmental Issues

Other chaptersBiomolecules (Biology)