Question

The ratio of the height of two plants X and Y is 2:1. If plant X grows at the rate of 2 meters
per year, at what rate should plant Y grow so that after 4 years they are of the same heightSingle choice.

Answer 1

Answer

(i) As it is given that plant is heterogeneous for two genes, hence it can be denoted as AaBb. Also, minimum height is 6 feet ( in case of aabb ) while this plant has 20 feet height. This is possible only if each dominant allele contributes height of 7 feet. In case of AaBb, there are two dominant alleles making it's height 6+7+7 = 20 feet.

(ii) the height of plants with genotype

a) AABb - here three dominant alleles are present hence 6+7+7+7 = 27 feet

b) AaBb - here two dominant alleles are present hence 6+7+7 = 20 feet.

Answer 2

Answer: (See attachment.)

Explanation: Let the growth of plant X be (2x) and that of plant Y be (x).

Rate of growth of plant X = 2 m/year

∴ Height of plant X after 4 year = (2x + 8) m

Let rate of growth of plant Y = (y) m/year

Height of plant Y after 4 years = (x + 4y) m

2x + 8 = x + 4y

→ x - 4y = - 8

Now, we may find the solutions of the linear equation. Atleast 2 is required.

1. If, x = 0 then y = 2.
2. If, y = 0 then x = - 8.

So, solutions are (0, 2) and (- 8, 0). They can of any height (especially evey point in the graph satisfied the relation.)