Answer:
Crossing two chickens heterozygous for the trait feather color, when brown feathers are dominant over red feathers, will produce offspring with brown and red feathers in a brown:red phenotypic ratio of 3:1.
Explanation:
Knowing that in chickens brown feathers are the expression of the dominant allele (B) and the recessive allele is red (b), crossing two heterozygous individuals (Bb) will result in offspring that are likely to have brown or red feathers.
The cross can be represented by a Punnett Square:
<u>Bb X Bb cross
</u>
alleles B b
B BB Bb
b Bb bb
Where the result is:
<u>Genotypes</u>:
<u>Phenotypes</u>:
- Brown feathers, 75%
- Red feathers, 25%.
In this case, the probability of having brown or red feathers is 3:1.
Answer:
life will not possible on Earth I think so
<span>The heart contains four chambers: upper left atria, upper right atria, lower left ventricle and the lower right ventricle. Oftentimes, the right atria and right ventricle are together referred to as the "right heart" and the left atria and left ventricle are referred to as the "left heart", however there are still four separate chambers.</span>
The skin is an example of a non-specific defense.
For example, bacteria or diseases have trouble entering a healthy person's skin because it is formed by closely packed cells with multiple layers and a substance called keratin that protects is.
On the other hand, the immune system is a specific defense mechanism.
When bacteria is able to enter the body in cases of fever for example, the immune system is activate and sends out protector cells such as the white blood cells to combat infection.
Ecological efficiency is the term used to describe how much energy will be passed from lower food pyramid level into the higher level. The amount of energy in primary level will be much higher than tertiary. The difference of level of tertiary(3) with primary(1) would be two level.
Assuming that the ecological efficiency is 10%, then the <span>primary consumer level would be: 50 kcal * 10^(3-1)= 5000 kcal</span>
