Answer: D. protection against a recent infection or disease is needed immediately
Explanation:
Passive immunisation is used when there is a high risk of infection and there is insufficient time for the body to build its own immune response or to mitigate the effects of active or immunosuppressive diseases.
Passive immunisation may be offered when people are unable to synthesise antibodies and when they have been exposed to a disease to which they have no protection. example of passive immunotherapy include monoclonal antibodies (MABs) or magic bullets which targets cancerous cells.
Hence, the correct option is D.
Answer:
C
Explanation:
The damage to DNA usually occurs where there are two consecutive thymine nucleotides on a DNA strand. The energy from the UV light causes the two dimers to form a cyclobutane pyrimidine structure. Proofreading and repair mechanism of DNA find it difficult to repair this kind of damage on DNA. During replication, therefore, DNA polymerase is unable to replicate this region hence leading to a mutation on the replicated strand at this local point.
Answer:
c the survival of the fittest
Explanation:
Answer:
Let's recall Mendel's law of independent assortment that states, "During the formation of gametes, alleles of genes assort independently into each gamete"
How can the random distribution of alleles result in a predictable ratio?
For example, We have a trait for flower color either yellow or white, and the alleles for the flower color are Y and y. The yellow flower color is a dominant trait, and be expressed if plant has YY or Yy genotype. We cross a plant with genotype Yy with another plant Yy.
P1 Yy x Yy
F1 YY : Yy: Yy: yy
Phenotype Yellow: yellow: yellow: white
Genotypic ratio 1 : 2 : 1
Phenotypic ratio 3 : 1
So, we see that phenotypic ratio is different from genotypic ratio. Although the distribution of alleles is random but still there are only four possible outcomes for a trait. Hence, we can predict the phenotypic and genotypic ratio of offspring by drawing a punnet square or gamete formation.
