Answer: a). AA
Explanation: Every trait is controlled by at least a pair of gene. Genes have different forms known as alleles. Alleles can be dominant or recessive. A dominant allele expresses itself in the presence of a recessive allele and masks the effect of a recessive allele. A recessive allele cannot express itself in the presence of a dominant allele and it's effect is masked by a dominant allele. Dominant alleles are usually written in upper cases such as A, T, while recessive alleles are usually written in lower cases such as a, t. The two alleles that determines a trait is called a genotype. A genotype can be homozygous if the two alleles are identical such as in AA or aa
and can be heterozygous if the two alleles are not identical such as in Aa, Tt.
We know that purebred means that the organism contains the same alleles for the trait and hybrid means that it contains two different alleles for the trait. Dominant means that it will be shown in a hybrid and a purebred, but recessive traits will only be shown in purebred recessive organisms.
a) The offspring of a purebred white (recessive) cow and a purebred brown (dominant) bull, would be all hybrid brown (dominant). This is because as I stated above, dominant traits are shown when the offspring has both dominant and recessive alleles for the same trait.
b) The offspring of a purebred brown (dominant) cow and a purebred brown (dominant) bull would all be purebred brown (dominant). This is because if both of the parents have only alleles that code for brown color, the only color that the offspring can be is brown.
c) The offspring of a purebred white (recessive) cow and a purebred white (recessive ) bull would all be purebred white (recessive), for the same reason stated above in part b), the only difference being that the alleles are recessive and code for white color instead of being dominant and coding for brown color.
d) The offspring of a hybrid brown (dominant) cow and a purebred white (recessive) bull would be half hybrid brown (dominant) and half purebred white (recessive). This can be seen best if you set up a Punnett Square, which is a diagram that shows allele frequencies in offspring. This shows you that the chance that the offspring get the dominant allele from the mother cow is 50%, thus 50% would be hybrid brown (dominant), as the father can contribute only a recessive white allele. The other 50% would be purebred white (recessive) because the mother cow would be contributing a white allele and so would the father.
Hope this helps! :)
Answer:
A. To ensure that your observations are complete and representative of the entire area
Explanation:
This is the most obvious choice, considering that every experiment you conduct requires using your five senses.
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Controls the movement of substances in and out of cells<span>. The basic </span>function<span> of the </span>cell membrane<span> is to protect the </span>cell<span> from its surroundings.
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