Answer:
It could be B. The parent have a hidden recessive gene for eye color.
Explanation:
I'll try to explain, because I've had tubes before. In fact, I still have them.
For me, tubes were put in because of too many ear infections, and excessive water in my ear. The tube helped drain the water out. You can see A picture I have in a file. The tubes can be put I believe in the ear drum. They're put there to help drain water that has trouble getting out on its own.
Answer:
Rr
Explanation:
This cross is a typical example of a test cross. A test cross is a cross between a heterozygous F1 progeny (different alleles) and a homozygous recessive parent in order to determine the actual genotype of the dominant parent i.e. whether homozygous or heterozygous dominance. In a test cross, if any of the offsprings show a recessive phenotype, it means the dominant parent is heterozygous
In this case, the allele for smooth pea (R) is dominant over that of wrinked pea (r).
If a cross between a smooth pea plant and a wrinkled pea plant gave rise to 50% phenotypical wrinkled pea plants (rr genotype, because the wrinkled shape can only express itself if it is in a homozygous state), it means that the smooth pea parent plant is heterozygous for pea shape (Rr) i.e. the allele for smooth shape was masking that of wrinkled shape in the smooth pea parent plant.
Answer:
A. 0.035.
Explanation:
Female : cv-cSb+/cv-c+Sb
Male : cv-cSb/cv-cSb ( since test cross involves mating with a recessive parent )
Their progeny:
cv-cSb+/cv-cSb : parental
cv-c+Sb/cv-cSb : parental
cv-c+Sb+/cv-cSbc : recombinant
cv-cSb/cv-cSb : recombinant
Wild type phenotype (cv-c+Sb+/cv-cSbc) is a recombinant. Distance between the two genes is 7mu. Since map distance is equal to recombination percentage, there will be 7% recombinants in the progeny. Out of total 7% recombinants, 3.5% will be cv-c+Sb+/cv-cSbc( wild type) and rest 3.5% will be cv-cSb/cv-cSb (mutant type).
Hence, proportion of phenotypically wild-type individuals in the progeny of the test cross will be 3.5% or 0.035.
Answer:
The lids of the Petri dishes were inadvertently left on while being sterilized
Explanation:
- The process of eliminating any microbe from a particular object to achieve a sterile aseptic environment is termed as sterilization.
- Sterilization mainly aims to either remove, kill or make any microbe inactive by using various means such as irradiation, heat, pressure, etc.
- In the given question radiation is used to sterilize the Petri dishes and thus, if sterilization is successful there should not be any contamination.
- However, since there is contamination present amongst the bacterial colonies growing on agar plated in the Petri dishes this shows that the sterilization has not been done successfully and a possible reason for this could be that while sterilizing the<em> lids of the Petri dishes were kept on. </em>