Answer:
by testcrossing with a homozygous recessive partner
Explanation:
<u>If a pet cockroach exists whose zygosity is unknown, this can be determined by a test cross. A test cross involves crossing an organisms whose zygosity is unknown with a partner that is homozygous recessive for the same trait.</u>
Let us assume that brown body is represented by the allele B, the dominant allele. The homozygous recessive version would be bb.
The genotype of a brown cockroach whose zygosity is not known can be denoted as B_, where '_' can be a 'B' or a 'b'.
When B_ is crossed with bb:
B_ x bb
Progeny
2 Bb
2 _b
The phenotype of Bb would be brown (since B is dominant over b) while the phenotype of _b would depend on the zygosity level of the cockroach.
If the unknown genotype is BB, then _b becomes Bb and the phenotype will be a brown body. This means that all the progeny will appear brown. (<em>see the first attached image for the Punnet's square</em>)
In other word, if the unknown genotype is bb, then _b becomes bb and the phenotype will be a alternate color (non-brown) body. This means that 50% of the progeny will appear brown while the remaining 50% will be in the alternate color. (<em>attached</em>
The outer core of Mars cooled too quickly and the magnetic field didn't have time to fully form so the solar winds destroyed the magnetic field and the atmosphere
Answer:
The correct answers are "The population of birds with large beaks will increase on the island" and "The trait for large beaks will be passed on to future generations through natural selection".
Explanation:
Natural selection functions under the premise of survival of the fittest, where stressful situations such as lack of resources will select the organisms with advantageous traits. In this case, the decrease on seeds affected particularly the numbers of small, soft seeds over large, hard seeds. This stressful situation will select the finches with the advantageous trait of having large beaks, because they are able to feed from large, hard seeds. This trait will be passed on to future generations through natural selection, which eventually will result in the population of birds with large beaks will increase on the island.
Answer:
The correct answer is - sexual transmission.
Explanation:
HIV infections can be transmitted by the various mode. Sexual transmission is one of the major mode of transmission which is comprise almost 90 % of HIV infection, according to the reports. These are relatively inefficient mode, unprotected or unnatural sex is the major mode for the HIV transmission worldwide. Cases are now comparatively less than when it was discovered due to awareness.
Thus, the correct answer is - sexual transmission.
Lactobacillus is a non spore forming bacteria
