Fossils of Lystrosaurus, a dicynodont therapsid, are most common in parts of modern-day South America, South Africa, Madagascar, India, South Australia, and Antarctica. It apparently lived in arid regions, and was mostly herbivorous. It originated during the mid-Permian period, survived the Permian extinction, and dwindled by the late Triassic, though there is evidence of a relict population in Australia during the Cretaceous. The dicynodonts had two large tusks, extending down from their upper jaws; the tusks were not used for food gathering, and in some species were limited to males. Food was gathered using an otherwise toothless beak. Judging from the fossil record, these pig-sized organisms were the most common mammal-like reptiles of the Permian. Anatomically, what was true of Lystrosaurus?

#Question id: 5724

#Unit 8. Inheritance Biology

Species I is diploid (2n  = 8) with chromosomes

AABBCCDD; related species II is diploid (2n = 8) with chromosomes MMNNOOPP. Individuals with the following sets of chromosomes represent what types of chromosome mutations?

A-   AAABBCCDD        B-   AABBCCDDMNOP

C-   AAABBCCDDD

#Question id: 5722

#Unit 8. Inheritance Biology

Meiotic products resulting from a single crossover within a pericentric inversion loop

A. This will generate a dicentric and an acentric chromosome following separation of chromosomes after crossing over

B. the inversion will completely suppress crossing over

C. All parental gametes that carry inversion chromosome are nonviable

D. All gametes from crossover products are non viable due to appearance of duplication of one arm and deletion of another arm

Which of the above statements are correct?

#Question id: 5721

#Unit 8. Inheritance Biology

There is paracentric inversion heterozygote ABCDEFG/ABFEDCG involved in double recombination during meiosis I within inverted region result in

A. dicentric and an acentric chromosome in meiosis I as the chiasmata get terminated.

B. appearance of deletion in both the cross over product

C. all gamete are viable

D. nonviable gametes from crossover products.

Which of the above statements are correct?

#Question id: 5720

#Unit 8. Inheritance Biology

Which two of the following are the CORRECT statements ?

P. Nondisjunction in the parental meiosis is not essential to produce diploid organisms

Q. Nondisjunction in the parental meiosis is essential to produce aneuploid organisms

R. Nondisjunction in the parental meiosis is essential to produce hexaploid organism

S. Nondisjunction in the parental meiosis is essential to produce tetraploid organisms

#Question id: 5719

#Unit 8. Inheritance Biology

Homologous chromosomes pair in prophase I as a following way, if crossingover occur between P and Q gene of homologous chromosome?

Which of the following proceeding event due to this abnormality?

A. Dicentric chromosome become breaks at anaphase I

B. Resulting one of the gamete received chromosome with deleted segment 

C. Recombinant gamete unable to produced viable progeny

D. Unable to separation of chromosome in anaphase II

#Question id: 5718

#Unit 8. Inheritance Biology

aneuploids may arise through nondisjunction, the failure of homologous chromosomes or sister chromatids to separate in meiosis. which of following the incorrect about nondisjuction ?