Perform a cross between a pea plant which is heterozygous tall and homozygous yellow with
another which is homozygous tall and heterozygous yellow. State the genotypic and phenotypic
ratio.
Answers
Answer:
In peas Tall (T) seeds are dominant over short (t) seeds and yellow (Y) seeds are dominant over green (y) seeds. When a cross is made between tall, yellow seeded (TTYY or TTYy or TtYY or TtYy) plant is crossed with short, green seeded (ttyy) plant, the number of progeny are 203 tall, green-seeded (TTyy or Ttyy) plants, 199 short, green-seeded (ttyy) plants, 207 tall, yellow-seeded (TTYY or TTYy or TtYY or TtYy) plants and 192 short, yellow seeded (ttYY or ttYy) plants.
Since, all four types of progeny are in the ratio of 1:1:1:1, this is an example of test cross. Test crosses is done to test the genotype of dominant parent (homozygous or heterozygous) by crossing it with a homozygous recessive parent. Hence, in the given example, the dominant parent is heterozygous and its genotype TtYy.
Thus, the correct answer is 'TtYy.'
Answer:
The correct answer is 'TtYy.'
Explanation:
In peas Tall (T) seeds are dominant over short (t) seeds and yellow (Y) seeds are dominant over green (y) seeds. When a cross is made between tall, yellow seeded (TTYY or TTYy or TtYY or TtYy) plant is crossed with short, green seeded (ttyy) plant, the number of progeny are 203 tall, green-seeded (TTyy or Ttyy) plants, 199 short, green-seeded (ttyy) plants, 207 tall, yellow-seeded (TTYY or TTYy or TtYY or TtYy) plants and 192 short, yellow seeded (ttYY or ttYy) plants.
Since, all four types of progeny are in the ratio of 1:1:1:1, this is an example of test cross. Test crosses is done to test the genotype of dominant parent (homozygous or heterozygous) by crossing it with a homozygous recessive parent. Hence, in the given example, the dominant parent is heterozygous and its genotype TtYy.
Thus, the correct answer is 'TtYy.'