The percentage of AB gametes produced by AaBb parent will be 25%.

Explanation:
To understand why the percentage of AB gametes produced by AaBb parent is 25%, we need to understand the concept of gamete formation through meiosis.

During meiosis, the chromosome pairs in a diploid cell separate, resulting in the formation of haploid gametes. In this case, the AaBb parent has two pairs of chromosomes, one pair for the Aa alleles and another pair for the Bb alleles.

- Law of Segregation:
According to Mendel's law of segregation, the alleles for each trait segregate during gamete formation. This means that during meiosis, the A and a alleles separate into different gametes, as do the B and b alleles.

- Independent Assortment:
Another principle known as independent assortment states that the alleles for different traits segregate independently of each other. This means that the segregation of alleles for the A trait does not influence the segregation of alleles for the B trait.

- Punnett Square:
To determine the possible combinations of alleles in gametes, we can use a Punnett square. For the AaBb parent, the Punnett square would look like this:

| A | a
----------------
B | AB | aB
----------------
b | Ab | ab

From the Punnett square, we can see that there are four possible combinations of alleles in the gametes: AB, aB, Ab, and ab.

- Calculation:
The percentage of AB gametes can be calculated by dividing the number of AB gametes by the total number of possible gametes. In this case, there is only one AB gamete out of the four possible gametes.

AB gametes = 1
Total possible gametes = 4

Percentage of AB gametes = (AB gametes / Total possible gametes) * 100%
= (1/4) * 100%
= 25%

Therefore, the percentage of AB gametes produced by the AaBb parent is 25%.