Question

Доминантные признаки у арбуза - круглые по форме и зеленая корка плодов, а рецессивные признаки - длинные по форме и полосатая корка плодов. Скрестили два дигетерозиготных растения арбуза с круглыми зелеными плодами между собой. Можно ожидать появления круглых полосатых арбузов от такого скрещивания? Ответ годтверди расчётами.

Answer 1

Объяснение:

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Answer 2

Dominant and Recessive Traits in Watermelon

Dominant traits are those that are expressed when an individual has at least one copy of the dominant allele, while recessive traits are only expressed when an individual has two copies of the recessive allele. In the case of watermelons, the dominant traits are round shape and green rind, while the recessive traits are elongated shape and striped rind.

Crossbreeding Two Heterozygous Watermelon Plants

In this scenario, two heterozygous watermelon plants with round and green fruits are crossed. Heterozygous means that each plant carries one dominant allele (R) and one recessive allele (r) for both shape and rind color. The possible genotypes for each parent plant are:

- Parent 1: Rr (round shape, green rind) - Parent 2: Rr (round shape, green rind)

When these two plants are crossed, the possible genotypes of the offspring can be determined using a Punnett square. In this case, the Punnett square would look like this:

    R   r
R  RR  Rr
r  Rr  rr

Expected Phenotypes of the Offspring

From the Punnett square, we can see that there are three possible genotypes for the offspring: RR, Rr, and rr. The corresponding phenotypes are as follows:

- RR: Round shape, green rind - Rr: Round shape, green rind - rr: Elongated shape, striped rind

Therefore, from this crossbreeding, we can expect to see watermelons with round shape and green rind, but not round and striped watermelons. The appearance of elongated shape and striped rind watermelons would require both recessive alleles (rr) to be present.

Confirmation through Calculations

To confirm the expected phenotypes, we can calculate the probability of each genotype