Parasitism is an interaction in while the host is harmed
Answer:
Of the trillions of cells that compose our body, from neurons that relay signals throughout the brain to immune cells that help defend our bodies from constant external assault, almost every one contains the same 3 billion DNA base pairs that make up the human genome – the entirety of our genetic material. It is remarkable that each of the over 200 cell types in the body interprets this identical information very differently in order to perform the functions necessary to keep us alive. This demonstrates that we need to look beyond the sequence of DNA itself in order to understand how an organism and its cells function.
Explanation:
Answer:
The environmental factor that could lead to a decrease in genetic variation in a tuna population is an increase in pollution (second option).
Explanation:
There is a correlation between genetic variability and environmental pollution, the latter being a factor that impacts negatively on the variability of a specific population.
The concept of pollution stress not only implies a low rate of reproduction, but it is also a factor that prevents genetic exchange with other populations, which is a factor that makes the genetic variability decrease in a population.
For these reasons an increase in pollution implies a decrease in genetic variability in a tuna population.
- <em>Other options, such as </em><u><em>an increase in food availability</em></u><em>, a</em><u><em> decrease in tuna fishing
</em></u><em> or </em><u><em>a decrease in tuna predators</em></u><em>, are environmental factors that contribute to increased genetic variability.</em>
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.
