Answer:
Daughters from fathers who were exposed to X-rays are infertile because there is possibility of lethal mutation in sperm due to irradiation which in turn was passed on to the daughters.
Hence, the females with ClB chromosome from their mothers and an X chromosome from their irradiated fathers will be infertile. It is due to the mutations that are passed on to the ClB daughters from the father.
As the mutations make the daughters infertile the reason behind this is that these mutations affect the production of ova in these females and make them infertilE.Hence, the control daughters whose fathers were not exposed to irradiation were more fertile when compared with the daughters with the fathers who were exposed to X-rays.
Answer:
The nonsense suppressors tend to be very inefficient by allowing read through of a stop codon in some cases.
If they are efficient, the peptide elongation would be terminated. The cell growth would be terminated because of the genes which have stop codons. There would be regular release factors and these appropriate release factors get associated with ribosome.
The inefficient nonsense suppressors which allow the read through the stop codons would waste the energy of the cell. The resulting protein will not be fully functional some times.
The suppression will be effective if the suppressor tRNA is charged with the correct amino acid and if the amount of tRNA or its concentration in the cell is sufficient. The efficiency of the suppressor also depends upon its context, of the base on 3'end of the codon.
Answer:
The ClB daughters whose fathers were exposed to Chemical B produced more number of tubes that lacked male offspring. So, chemical B can be considered as a mutagen. The control ones produced only three tubes out of 2,108. When this number is compared with the number produced by chemical B, (77 out of 4,203) it can be very well concluded as a mutagen.
The ClB daughters, whose fathers were exposed to chemical A, produced two test tubes which lacked male offspring. The ratio was two out of 1,402. This number is very close to the control ones which is three out of 2,108. Hence, chemical A cannot be considered as a mutagen.
The percentage of ClB daughters (whose fathers were exposed to chemical B) who could not produce sons is much higher than the contol ones. So, chemical B is a mutagen.