Consider a monohybrid cross between a pure tall plant and a dwarf plant. In F2 generation of this cross 4000 seedlings were produced. How many seedlings will be tall?

Doesn't it depend upon which trait is dominant? I believe the answer is 3000 of one and 1000 of the other, if this is like Mendel's peas.

http://anthro.palomar.edu/mendel/mendel_1.htm

To determine the number of seedlings that will be tall in the F2 generation, we first need to understand the basic principles of Mendelian inheritance.

In a monohybrid cross between a pure tall plant (TT) and a dwarf plant (tt), the tall plant (T) is dominant, while the dwarf plant (t) is recessive.

In the F1 generation, all the offspring will be heterozygous tall plants (Tt) because they inherit one copy of the tall allele (T) from the tall parent and one copy of the dwarf allele (t) from the dwarf parent.

Now, for the F2 generation, we need to determine the possible genotypes of the offspring. When two heterozygous tall plants (Tt) are crossed, there are three possible genotypes: TT (tall), Tt (tall), and tt (dwarf).

To figure out the ratio of tall to dwarf plants in the F2 generation, we can use the Punnett square or the probability approach.

Using the probability approach, let's consider the possible genotypes:

1. TT (tall) - There is a 25% chance to get this genotype because there is a 50% chance (1/2) of inheriting the tall allele from each parent (Tt x Tt).
2. Tt (tall) - There is a 50% chance to get this genotype because there is a 50% chance (1/2) of inheriting the tall allele from one parent (Tt) and a 50% chance (1/2) of inheriting it from the other parent (Tt).
3. tt (dwarf) - There is a 25% chance to get this genotype because there is a 50% chance (1/2) of inheriting the dwarf allele from each parent (Tt x Tt).

Now, to determine the number of seedlings that will be tall in the F2 generation, we need to calculate the percentage or proportion of tall plants.

1. Calculate the number of seedlings with the TT genotype: 4000 x 0.25 = 1000 seedlings (25% of 4000).
2. Calculate the number of seedlings with the Tt genotype: 4000 x 0.50 = 2000 seedlings (50% of 4000).
3. Add the number of seedlings with the TT and Tt genotypes to get the total number of tall seedlings: 1000 + 2000 = 3000 seedlings.

Therefore, in the F2 generation, 3000 seedlings will be tall.