Louis Pasteur’s experiments has taken a leap on cell biology. He was able to contribute to the concept of cell theory which suggests that cells came from pre-existing cells, cells are the fundamental unit of life and that all life have cells.
Highlighting on pre-existing cells, early before the experiments of Pasteur, there was the theory of spontaneous generation. This theory claims that organisms came from nonliving objects which is now, truly misleading and wrong.
Answer:
the ducks have associated people with food handouts and so they become close.
Explanation:
Answer:
Heterozygous dominant (Bb) and homozygous recessive (bb)
Explanation:
This cross involves the gene that codes for color blindness in whales. The allele for no color blindness/normal vision (B) is dominant over the allele for color blindness (b). This means that B will mask the phenotypic expression of b in a heterozygous state (Bb).
According to the question, one of the parents is color blind meaning it possesses the homozygous recessive genotype (bb) while the other parent (pearl) has a normal vision which can either be homozygous dominant or heterozygous dominant since the normal vision allele (B) is dominant.
However, since one of the two offsprings (sons) is also color blind, this implies that the parent with normal vision is heterozygous i.e. contains both dominant and recessive alleles, for the trait. What happens is that, when a bb and Bb parent are crossed, they produce gametes with either a recessive or dominant allele.
The Bb produces gametes with B and b alleles while the bb produces gametes with b and b alleles. When this are crossed using a punnet square, four possible offsprings will be produced with two distinct genotypes: Bb and bb. Hence, this means that there is a 1/2 chance of producing an offspring with the recessive trait from this cross as the case is in the whales.
The correct answer is: B) binding to their substrate
The catalytic mechanism of an enzyme starts when the substrate binds to its active site (specific region of an enzyme). There is a theory (lock and key) that explains the mechanism of this binding: the lock is the enzyme and the key is the substrate and only if they fit the enzyme will work. The binding of the substrate to the enzyme causes conformational changes of the enzyme, and as a result, products are formed. The products are then released from the surface of tat enzyme. The enzyme is regenerated for another reaction cycle.
