Question

15. Differentiate between maternal inheritance and nuclear/general inheritance.

16. Explain how transformation was discovered and how it relates to the material of inheritance.

17. Explain how bacteriophage were used to show that DNA was the material of inheritance.

18. Explain how mutations are the toolbox of the geneticist and how mutations can be induced.

19. Explain the tetranucleotide hypothesis and how it was refuted by Chargaff. Explain the numerical relationships between nucleotides in a DNA molecule.

Answer 1

1. Maternal inheritance is due to genetic variants of mitochondria or chloroplasts ,which are generally transmitted to the oocyte. It is due expression of extranuclear DNA present in the ovum during fertilization .maternal inheritance has a great influence on the off spring gene action,fitness and evolution.

Nuclear inheritance is the transmission of gene that occur outside the nucleus .it is found mostly in eukaryotes,and also occur in cytoplasmic organelles such as mitochondria chloroplasts .also take place in cellular parasites like viruses and bacteria.

2.Transformation is the genetic alteration of cell by direct uptake and Expression of DNA from its surroundings and it occurs in some type bacteria. It is discovered in streptococcus pneumoniae,that determines the polysaccharide character of S.

3.T2 bacteriophage was used in the experiment.In which nucleic acid of phage molecule were required for their replication with in the bacteria .Result of this experiment supported the DNA is only the genetic material.

Genetic material located in a region called the nucleoid,DNA exist as circular compact chromosome.A cell have additional genetic material located in structures called plasmids ,wHich separate from the main genetic

4. Mutation induced in variety of ways such as exposure of uv ,ionizing radiation, chemical mutagens and alter genetic traits and selecting for improved progeny.

In bacteria mutation changes their genetic code,it is beneficial to the organism .

Harmful mutation cause cancer.

I have to complete first 4 questions