A steam steriliser is used to sterilise liquid medium for fermentation. The initial concentration of contaminating organisms is 10⁸ per litre. For design purposes, the final acceptable level of contamination is usually taken to be 10^-3cells; this corresponds to a risk that one batch in a thousand will remain contaminated even after the sterilisation process is complete. For how long should 1 m³ medium be treated if the temperature is 80⁰C ________________.10^6

 To be safe, assume that the contaminants present are spores of Bacillus stearothermophilus, one of the most heat-resistant microorganisms known. For these spores the activation energy for thermal death is 283 kJ gmo1^-1 and the Arrhenius constant is 10^36.2 s^-1

#Question id: 4727

#Section 3: Genetics, Cellular and Molecular Biology

if mendal had studied the seven trait using a plant with 12 chromosome instead of 14, in what manner would his interpretation have been different ?

#Question id: 4728

#Section 3: Genetics, Cellular and Molecular Biology

The genotype r/r ; p/p gives fowl a single comb, R/– ; P/– gives a walnut comb, r/r ; P/– gives a pea comb, and R/– ; p/p gives a rose comb. Which of the following parental genotype would produce 3/8 Walnut comb, 1/8 pea comb, 3/8 rose comb and, 1/8 single comb?

#Question id: 4729

#Section 3: Genetics, Cellular and Molecular Biology

In the following example, 3 independently assorting genes A, B and C are known to govern coat color in mice. Homozygous recessive cc (albino phenotype) is epistatic over both gene A and B, What will be the expected frequency of non albino, in the progeny from cross of AaBbCc with genotype of AABbCc?

#Question id: 4730

#Section 3: Genetics, Cellular and Molecular Biology

Cross is made between a pure breeding plant having red coloured male flowers with a pure breeding plant having white colored female flowers. All of these offspring are white colored flower. Upon selfing of these F1 red flower plant produced both red and white flower. Which of the following is conclusion of these cross?

#Question id: 4731

#Section 3: Genetics, Cellular and Molecular Biology

A pure-breeding strain of squash that produced disk-shaped fruits was crossed with a pure breeding strain having long fruits. The F1 had disk fruits, but the F2 showed a new phenotype, sphere, and was composed of the following proportions

Disk  384            

Sphere 96

 Long  32

What is reason for F2 phenotype?

#Question id: 4732

#Section 3: Genetics, Cellular and Molecular Biology

What is F2 phenotype ratio observed when a homozygous recessive mutation in either or both of two different genes results in the same mutant phenotype?