Ans.
Sex-linked genes are those genes that found on sex-chromosomes (X and Y chromosomes) and their phenotypic expression for a trait depends on the gender of the offspring.
Most of the sex-linked genes are present on X chromosomes as X chromosomes have more number of genes as they are made up of more DNA as compared to Y chromosome.
However, male individuals are more likely to exhibit the sex-linked traits. It is because most of the sex-linked traits are recessive and males have only one copy of X chromosome, while females have two copies of X chromosome. One mutated copy in male can exhibit the trait, while in females, both of the mutated copies are required to exhibit that trait.
Answer:
D. Fossil record.
Explanation:
The fossil record evidences the evolutionary history of life on Earth by tracing the life forms that existed from earlier geological times and remained in the sedimentary rock. Different fossils were dated in the sedimentary rocks of all geological periods. The simplest forms of life were discovered in the oldest rocks, while more complex fossil organisms were found in the newest rocks. In consequence, the fossil record can support the evolutionary process as proposed by Charles Darwin, who indicated that the simplest forms of life evolved in more complex organisms.
TDS, Total dissolved solids (TDS) is measured as a volume of water with the unit milligrams per liter
Answer:
Option C
Explanation:
All of the following options are correct except option C. in the Meselson Stahl experiment, after the first round of replication, the DNA molecules made consisted mainly of one parental strand and one new strand each which is the DNA molecules of intermediate density (H-L). Then future replications will produce more of the low density L-L density. This form of replication is thus termed to be the semi conservative form of replication