67 million years ago in the form of phyollths (small sllica flecks in grass that make it difficult to digest)
Answer:
Which type of selection tends to increase genetic variation? A. Disruptive selection B. Directional selection C. Stabilizing selection
The Answer is option A (Disruptive selection)
Explanation:
Selection can either shift the mean value of a trait, reduce the trait's variation, or increase its variation.
Genetic variation which allows natural selection to increase or decrease frequency of alleles already in the population is a source of phenotypic variation as it refers to differences in all the hereditary information of members of the same species.
Disruptive Selection is important in maintaining variation and initiating speciation as it Increases Variation by favoring alleles corresponding to more extreme phenotypes. But for it to occur, the mean phenotype has to experience the lowest fitness. Disruptive selection affects the frequency distributions of alleles and genotypes within a population.
Disruptive selection is based on the variance of a trait in a population as it increases genetic variance by equalizing the frequencies of existing alleles at polymorphic loci (a genetic loci with two or more alleles). Disruptive selection maintains and may even increase variation in natural populations by favoring extreme phenotypes, individuals with extreme values for a trait have greater reproductive success than individuals with intermediate values.
Answer:
organelles such as nuclei, mitochondria or chloroplast
Answer:
Troponin
Explanation:
This is a complex of three proteins (Trop C, I, T) that are responsible for muscle contraction of the skeletal and cardiac muscles . its binds with protein tropomysin to lie in the grove between the actin filaments. its prevents contraction by blocking myosin crossbridge in a relax muscles.Inorder to aid contractions calcium ions binds with troponin, which leads to confrontational change.This exposes myosin on actin filaments, leading to formation of crossbridge and therefore contraction of muscles.
Therefore if there is a mutation in the gene that encoded Troponin, as explained above, calcium ion will not be able to bind with tropinin, and there will be no exposure of myosin on actin filaments, no binding of myosin on actin to cause crossbridge, and consequently no muscle contraction,
Thus the intercoastal muscle and diaphragm will not contract leading to death of the baby.
Answer:
Limiting human use of nitrogen that is in the atmosphere.
Explanation:
