In this article we will discuss about the structure of chlamydomonas (explained with labelled diagram). The unicellular green alga Chlamydomonas is haploid with a single nucleus, a chloroplast and several mitochondria (Fig. 9.3). It can reproduce asexually as well as sexually by fusion of gametes of opposite mating types (mt+ and mt-). The mating type is controlled by a single [...]
Sonneborn in 1938 discovered certain strains in Paramecium which showed a killer trait due to the presence of a cytoplasmic factor called kappa. The killer strain can destroy the sensitive strains growing in culture which do not have kappa by liberating a toxic substance paramecin. Killer strains are not killed by their own paramecin. Paramecium has two kinds of nuclei, [...]
In this article we will discuss about the five main DNA repair mechanisms that are studied in eukaryotes. The mechanisms are: 1. Photo-Reactivation or Photo-Repair 2. Dark or Excision Repair 3. Nucleotide Excision Repair 4. Mismatch Repair 5. Post-Replication Repair. Mechanism # 1. Photo-Reactivation or Photo-Repair: This mechanism was discovered when bacteria that had been heavily irradiated with UV rays [...]