Question

1)У арбуза шаровидные плоды ( A ) доминируют над длинными ( a ), а зелёная окраска ( B ) — над полосатой ( b ). Отметь генотип растений с шаровидными зелёными плодами. AABB AAbb Aabb aaBB 2)У тыквы доминантный признак — дисковидные плоды. Проведено анализирующее скрещивание растений тыквы, имеющих такой признак. Было получено 50 особей, среди которых 25 — с шаровидными плодами и 25 — с дисковидными плодами. Выбери характеристики генотипа анализируемых растений: гомозиготы по доминантному признаку имеют гетерозиготный генотип гомозиготы по рецессивному признаку aa Aa AA 3)У гороха жёлтая окраска семян A доминирует над зелёной a , а гладкая поверхность B — над морщинистой b . Определи генотип растений гороха, имеющих доминантные признаки, если при анализирующем скрещивании получено 480 растений: все — с жёлтыми гладкими семенами . aaBb aabb AABB AABb AAbb 4)У гороха гены, отвечающие за развитие усиков и формы семян, расположены в одной паре гомологичных хромосом. Доминируют усики и гладкие семена. Доминантные гены локализованы в одной хромосоме на расстоянии 16 морганид. Скрещены дигетерозиготные растения с гомозиготными, имеющими морщинистые семена, но не имеющим усиков. Найди вероятность (%) появления в потомстве растений с морщинистыми семенами без усиков. (Запиши число).

Answer 1

Question 1:

The genotype of plants with round green fruits can be determined by the given information. Let's analyze the options:

- AABB: This genotype represents plants with round dominant fruits (A) and green color (B). This matches the given information. - AAbb: This genotype represents plants with round dominant fruits (A) and striped color (b). This does not match the given information. - Aabb: This genotype represents plants with round dominant fruits (A) and striped color (b). This does not match the given information. - aaBB: This genotype represents plants with elongated recessive fruits (a) and green color (B). This does not match the given information.

Therefore, the genotype of plants with round green fruits is AABB.

Question 2:

To determine the characteristics of the genotype of the analyzed plants, let's analyze the given information:

- Heterozygotes for the dominant trait have a heterozygous genotype. - Homozygotes for the dominant trait have a homozygous genotype. - Homozygotes for the recessive trait have a recessive homozygous genotype.

Based on the given information, we know that 25 plants have round fruits and 25 plants have disc-shaped fruits. This indicates that the ratio of the dominant trait (round fruits) to the recessive trait (disc-shaped fruits) is 1:1.

From this information, we can conclude that the analyzed plants have a heterozygous genotype (Aa) for the dominant trait.

Question 3:

To determine the genotype of pea plants with dominant traits, let's analyze the given information:

- Yellow seed color (A) is dominant over green seed color (a). - Smooth seed surface (B) is dominant over wrinkled seed surface (b).

From the given information, we know that all 480 plants have yellow smooth seeds. This indicates that the ratio of the dominant trait (yellow smooth seeds) to the recessive trait (green wrinkled seeds) is 4:0.

Based on this information, we can conclude that the genotype of the pea plants with dominant traits is AABB.

Question 4:

To calculate the probability of obtaining plants with wrinkled seeds and no tendrils in the offspring, let's analyze the given information:

- The genes responsible for the development of tendrils and seed shape are located on the same pair of homologous chromosomes. - Tendrils and smooth seeds are dominant traits. - The dominant genes are located on the same chromosome at a distance of 16 morgans.

When digenic heterozygous plants (AaBb) are crossed with homozygous plants that have wrinkled seeds and no tendrils (aabb), the offspring will have the following possible genotypes:

- AB: Tendrils and smooth seeds - Ab: Tendrils and wrinkled seeds - aB: No tendrils and smooth seeds - ab: No tendrils and wrinkled seeds

The probability of obtaining plants with wrinkled seeds and no tendrils in the offspring can be calculated using the Punnett square. Since the genes are located on the same chromosome, the probability is determined by the recombination frequency, which is given as 16 morgans.

The recombination frequency of 16 morgans corresponds to a probability of 16%. Therefore, the probability of obtaining plants with wrinkled seeds and no tendrils in the offspring is 16%.