Answer:
True
Explanation: They can digest food moleclues that enter the cell into smaller pieces
1. All thriving things need energy in order to defend themselves (escape danger) and perform functions such as growth, maintaining balance, repair, reproduction, movement.
Sorry, I don't completely understand the second one
Answer:
0.095
Explanation:
Phenylkentonuria is a disease caused by a recessive allele.
The frequency of the recessive allele + the frequency of the dominant allele equals 1.
The frequency of the recessive allele is q = 0.05
The frequency of the dominant allele then is p = 1 - q = 0.95
If people mate randomly, the frequency of the homozygous dominant genotype will be p², the frequency of the heterozygous genotype will be 2pq and the frequency of the homozygous recessive genotype will be q² .
2pq=2× 0.05 × 0.95
2pq=0.095
The heterozygote frequency in the population is 0.095
Answer:
8. D
9. A
10. A
11. C
12. D
Explanation:
8. Natural selection works on variation that exists in the genes of organisms. Antelopes who have genetic variation that makes their legs more muscular are at an advantage because they can outrun predators. This increases the chance that they will reach reproductive age, and be able to pass this advantageous trait onto their offspring. Over time, this selection pressure makes the variant more common in a population.
9. Beneficial traits are those that give a selective advantage. This could be one that helps it outrun predators (like above), avoid illness and death, gives it a reproductive advantage (i.e. more attractive to mates), or makes it better able to digest certain foods, for example. The formation of cancer cells would be harmful for an organism, reducing its fitness and perhaps leading to death. The inability to reproduce would mean genetic info is not passed on to the next generation, and stopping the production of an essential protein would likely lead to death. However, resistance to a virus would help an organism avoid illness and death, improving fitness.
10. Genotypes are what organisms inherit from their parents, i.e. the genetic information that is passed on. However, the way in which different alleles interact and are expressed is the phenotype. If we take the above example, natural selection is acting on the phenotype of muscular legs. If an antelope had the muscular leg genotype but for some reason it was not being expressed (maybe another gene is interfering with it), then the antelope would not have a selective advantage, and natural selection could not be act on the trait.
11. A trait that better suits an organism to its environment will be selected for by natural selection. This is because that organism is more likely to survive due to the trait, giving it a selective advantage. Therefore, if a mutation arose making the giraffe more adapted to the environment, it would be positively selected for, and through evolution would become more common.
12. This is an example of selective breeding, which has been happening for generations. Farmers spot desirable traits, and cross horses with these traits in an attempt to enhance the trait or to ensure it is passed on to the next generation. This is not natural selection, because farmers are making it happen artificially. It is not cloning or recombinant DNA, which are terms scientists use for actually manipulating the DNA in the lab.
<span>Constructing recombinant DNA or rDNA scientists
should combine both DNA from two different species. Based on study, rDNA
is possible if both DNA that should be combined should have the same chemical </span><span>structure.
Most o the DNA do have the same structure they only differ in nucleotide
sequence. </span>
