Related questions with answers

Can you identify the genotype of a person with a normal melanin? Why or why not?

Acridine orange is a chemical that inhibits the replication of $\mathrm{F}$ factor DNA but does not affect the replication of chromosomal DNA, even if the chromosomal DNA contains an Hfr. Let's suppose that you have an E. coli strain that is unable to metabolize lactose and has an $\mathrm{F}$ factor that carries a streptomycin-resistant gene. You also have an $F^{-}$ strain of E. coli that is sensitive to streptomycin and has the genes that allow the bacterium to metabolize lactose. This second strain can grow on lactose-containing media. How would you generate an $H f r$ strain that is resistant to streptomycin and can metabolize lactose? (Hint: F factors occasionally integrate into the chromosome to become $\mathrm{Hfr}$ strains, and occasionally $\mathrm{Hfr}$ strains to excise their DNA from the chromosome to become $\mathrm{F}^{+}$ strains that carry an $\mathrm{F}^{\prime}$ factor.)

A sex-influenced trait is dominant in males and causes bushy tails. The same trait is recessive in females and results in a normal tail. Fur color is not sex influenced. Yellow fur is dominant to white fur. A true-breeding female with a bushy tail and yellow fur was crossed to a white male without a bushy tail. The $\mathrm{F}_1$ females were then crossed to white males without bushy tails. The following results were obtained:

\begin{array}{lc} \text { Males } & \text { Females } \\ \hline 28 \text { normal tails, yellow } & 102 \text { normal tails, yellow } \\ 72 \text { normal tails, white } & 96 \text { normal tails, white } \\ 68 \text { bushy tails, yellow } & 0 \text { bushy tails, yellow } \\ 29 \text { bushy tails, white } & 0 \text { bushy tails, white } \end{array}

A. Conduct a chi-square analysis to determine if these two genes are linked.
B. If the genes are linked, calculate the map distance between them. Explain which data you used in your calculation.

Question

The type of model building used by Pauling and Watson and Crick involved the use of ball-and-stick units. Now we can do model building on a computer screen. Even though you may not be familiar with this approach, discuss the potential advantages of using computers in molecular model building.

Solution

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Answered 2 years ago

The advantages of using computer simulations for building molecular models are given below:

Offers better flexibility in terms of number of components and the way in which they can interact.
Offers precise control over several parameters that are not possible otherwise.
Does not require physical structures/objects such as ball, sticks, etc.
Can perform multi-parametric simulations with many possible combinations of the components.
Easy to construct complex models.
Molecular models are easier to make multiple copies and for sharing with others.