Answer:
The "short tail" dominant allele is easier to eliminate by selective breeding.
Explanation:
The only way for a recessive allele to be expressed (be visible) is when it appears as recessive homozygotic. These means the organisms need to have 2 copies of the gene. Selective breeding is based on the characteristics that one can see, so if the organism shows the "dilute" phenotype you can keep reproducing this individuals and get rid of the dominant allele.
On the other hand if you have a population with the dominant phenotype, you discard all the ones that have a recessive trait and you breed the dominant phenotype you could still get individuals with the recessive phenotype and individuals that express the dominant phenotype but are heterozygous.
B. Pine trees, this is the answer that was right after I took the test XD
ANSWER FOR QUESTION 1:
The most common type of E. coli infection that causes illness in people is called E. coli O157, which produces a toxin known as Shiga-toxin. Shiga-toxin producing E. coli is abbreviated as STEC. Symptoms of infection with this germ include watery or bloody diarrhea, fever, abdominal cramps, nausea, and vomiting.
ANSWER FOR QUESTION 2:
Some other germs don’t cause as many illnesses, but when they do, the illnesses are more likely to lead to hospitalization. Those germs include: Anyone can get sick from eating contaminated food. Follow four simple food safety steps —clean, separate, cook, and chill—to lower your chance of food poisoning and to protect yourself and your loved ones.
This is an example of; evolution
Evolution is a gradual process in which the characteristics of a species are changed in response to its environment over several generations. Evolution depends on the process of natural selection. Some of the changed characteristics (traits) may be beneficial to the organism and it can be transferred to their offspring.
Answer:
If the two organisms are heterozygous for the dominant trait.
Explanation:
For every trait, a diploid organism receives two forms of gene called ALLELE, from each parent. Allele is the variant form of a gene.
According to Mendel's law of dominance, for a particular trait, an allele is capable of masking the expression of another allele in a gene. The expressed allele is called the DOMINANT allele while the masked allele is called the RECESSIVE allele. Due to this, an organism can express a dominant trait even in a combined or heterozygous state i.e. different alleles.
When the two heterozygous organisms mate or are crossed, they undergo meiosis and their alleles are separated into GAMETES according to Mendel's law of segregation. For example; an organism with genotype (genetic make-up) Aa will produce gametes with A and a alleles.
Note that, a recessive trait can only be expressed in a homozygous state i.e. same allele. Hence, the two heterozygous organisms will produce gametes containing the recessive allele, which will likely combine to produce a recessive phenotype or trait.
