Answer:
The correct answer is option (d)-"immunity to reinfection by any phage".
Explanation:
Lysogeny is one of the two cycles that comprise viral reproduction, at which the bacteriophage genetic information is introduced into the host bacterium's genome. Lysogeny could result in immunity to reinfection by the same phage, however this not happens when the reinfection takes place by any phage. When reinfection occurs by the same phage, the host bacteria acquires immunity resulting from the recognition of their particular DNA sequences. This not happens when reinfection occurs in any phage as they could have different DNA sequences.
Answer:it was very effective.
Explanation:
According to report in America 1954, Salk conducted a national study, with over a million paediatric subjects wish yielded a positive outcome and on 12 April 1955, the vaccine was considered safe and efficacious. in 1955, the vaccines was used for over 29,000 cases of poliomyelitis in the US and the infection rate reduced to less than 6,000. This made Salk vaccine more recognized and it was speedily adopted worldwide reaching almost 90 countries in less than 2 years after it mass production.
Answer:
C. A1A2, A1A3
Explanation:
This question depicts a gene coding for coloration in a flowering plant. The gene is controlled by multiple alleles, three specifically. The alleles are labelled A1, A2, and A3, with each coding for it's own respective trait.
According to the question, A1 is dominant over A2 and A3 i.e. A1 will always mask the phenotypic expression of A2 and A3 and express itself. Also, A2 is dominant over A3 i.e. A2 will always mask the phenotypic expression of A3. This overall means that the trait encoded by allele A3 will only be expressed when the same alleles are present.
To the question; since A1 is dominant over the other two alleles (A2 and A3), it will be phenotypically expressed ahead of them in a heterozygous state with both alleles. That is, A1A2 genotype will give rise to a phenotype encoded by A1. Also, A1A3 will produce a phenotype encoded by A1. Hence, genotypes A1A2 and A1A3 will express the same phenotypes.
A2A2 and A3A3 will express different phenotypes since they are both in a same alleles condition. Likewise for A1A1 and A3A3. A2A3 and A1A3 genotypes will express different phenotypes encoded by A2 and A1 respectively since they are both dominant over A3.
Answer:
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from a single cell or from a multicellular organism inherit the genes of that parent.
Explanation:
Answer:
lithosphere
Explanation:
Earth's lithosphere includes the crust and the uppermost mantle, which constitute the hard and rigid outer layer of the Earth. The lithosphere is subdivided into tectonic plates. Further there are two types of lithosphere mainly as oceanic and continental lithosphere.
