3 Four species of ground beetle in the genus Carabus are kno

3. Four species of ground beetle in the genus Carabus are known to be diploid and have the chromosome constitutions shown: C aneus, AA; C barbadense, BB: C carinata, CC; C densisetus, DD. It is known that aneus has a diploid number of 14 and that densisetus has a diploid number of 24; none of the diploid species has the same number of chromosomes as any other. Several other species discovered are thought to be polyploid; these species are C. eviscerata, C fulvoguttata, C gracilis, C hirsutum, and C introspecta. Of these species, only eviscerata has been studied in any detail; it is an allopolyploid with the constitution AABB. Crosses were done between these species, but the field notes got wet and the ink ran; thus the only data available are compiled below: Species and/or hybrid Chromosomes Bivalents Univalents 12 eviscerata 22 fulvoguttata gracilis hirsutum 54 27

Solution

Answer 3: Number of chromosome in genus Carabus whose two species are deploid which are C.aneus and C.densisetus contain two complete sets of chromosome which are 14 and 24 respectively.

Polyploids have more than 3 sets of chromosome, Ploidy number contain 3n chromosome are triploid and come in category of autopolyploid from a cross of 4nx2n.The 2n and the n gametes unite to form a 3n triploid. they are generally sterile. allopolyploids organism contain 2 or more set of chromosome from two different species.Chromosome constituent for allopolyploid are described as in 2n1+2n2 tissue, there is a pairing partner for each chromosome, and balanced gametes of the type n1+ n2 are produced. These gametes fuse to give 2n1+2n2 allopolyploid progeny, which are fertile also called double deploid.

The Karyotype found in ground beetle are 2n=37 chromosome. In most species, the ribosomal clusters occupy a distal position in one chromosome arm. This localization of rDNA genes has already been reported in carabids or ground beetles.