In cucumbers, dull fruit (D) is dominant to glossy fruit (d), and orange fruit (R) is dominant to cream (r) fruit. The genes coding for dull and glossy assort independently from the genes coding for orange and cream. A plant that has dull and orange fruits is crossed to a plant that has dull and cream fruits. The cross produces 3⁄8 plants with dull and orange fruits, 3⁄8 plants with dull and cream fruits, 1⁄8 plants with glossy and orange fruits, and 1⁄8 plants with glossy and cream fruits. Give the genotypes of the parents and offspring of the cross.
Generation | Genotypes | ||
---|---|---|---|
P | 9j7AuVvXg3ivc2vjSXe1ag== | × | gIBNsGJrWXh7r45cVOe9HA== |
↓ |
What information is the problem asking you to provide? (check all that apply)
wCfH0QtRgXJ8o+c+ | The phenotypes of the parents. |
wCfH0QtRgXJ8o+c+ | The phenotypic ratios of the progeny. |
bI0LPa9lfHQ+dYqk | The genotypes of parents and progeny. |
wCfH0QtRgXJ8o+c+ | Genotypic ratios of the progeny. |
Outline the phenotypes of the parents and offspring by choosing from the drop-down menus below.
Generation | Phenotypes | ||
---|---|---|---|
P | G8ptcFpX+mGBt6UXRfgOkJHc6/h7oA2kWnPjesg21DnCo/eQgN4YF7Nh8qiScpcAiln9AuxifHHlGK3qsfAThmpSSI1Xf1h+HfRqxCRPVI3X3hQVgfhVlKp87nStz2r7zN+tZ4tT+wd0INDp | × | KZtaelMiS0x6f6mO0YrDxK7LpcGaGr0jkM2hK3jB5lIkI4UVIm+o7e2l9Ffq7p3RpIGF/LzG1HLJgJnB3ABLRsafCUFp448H4alRcR8rzg3pYo6hoWsuOOCzrS0v21LGwMBfolsQgYMY2cfl |
↓ | |||
F1 | 3⁄8 | G8ptcFpX+mGBt6UXRfgOkJHc6/h7oA2kWnPjesg21DnCo/eQgN4YF7Nh8qiScpcAiln9AuxifHHlGK3qsfAThmpSSI1Xf1h+HfRqxCRPVI3X3hQVgfhVlKp87nStz2r7zN+tZ4tT+wd0INDp | |
3⁄8 | KZtaelMiS0x6f6mO0YrDxK7LpcGaGr0jkM2hK3jB5lIkI4UVIm+o7e2l9Ffq7p3RpIGF/LzG1HLJgJnB3ABLRsafCUFp448H4alRcR8rzg3pYo6hoWsuOOCzrS0v21LGwMBfolsQgYMY2cfl | ||
1⁄8 | rpsrbvVUToVPMhvg8UcKqpH4xuwDqdMGoYeyluqKciPjQoynac6sELg1OxQSm2vaDaLAjB1vX7uNICBOwPhjMxWn7tK5L18pGLmI/EVCzq/ZcLPbCfkXdy4tXxxIH4bUGZ46/Gf8jlAtSSO2 | ||
1⁄8 | 5ZIWpbY97uEpTMg/OCn64SzkIj3iWm5VsSkMidMN5JCLrgPJel8TRotBc4upJ83hj4MCl5G816P8vZDPdhkazqu7RVJsNpjtYCTF7r82+6rAzpLYhuboSwinoxIojVvW/zDyXzdHPCesQpOI |
Give the allelic symbols to be used for each trait:
Texture | |
---|---|
dull | DD7UQIIkhDI= |
glossy | ujZVRF1sK00= |
Color | |
---|---|
orange | k2tcaXUqHdo= |
cream | oUDghrXV/HA= |
In cucumbers:
According to the problem, Genes for texture and color assort tXnTOn6YvSt+25kNY/r8uvPJkfviVPbL3dGSXH1gcQY=, meaning that they are located on sxVYmW9LnZscmfI85zFMEz0YvgdKyffg chromosome(s).
Now determine what you know about the allelic symbols for the genotypes of the parents, using only what you know from the phenotypes given in the question (not the progeny) to guide you. Use an underscore (_) to indicate any genes you feel you can not ascertain from the phenotypes.
Great. Now fill in the parental genotypes in the table below.
Generation | Genotypes | ||
---|---|---|---|
P | kNZiw76BruM/5Hg+yvTEyhKbLuU= | × | 0Ea8S69N9GGkVuc+dYnzrQ== |
↓ | |||
F1 | 3⁄8 | ?? | |
3⁄8 | ?? | ||
1⁄8 | ?? | ||
1⁄8 | ?? |
Now determine what you know about the allelic symbols for the genotypes of the progeny. Use an underscore (_) to indicate any genes you can not ascertain from the phenotypes.
Now fill in the genotypes of all the progeny.
Generation | Genotypes | ||
---|---|---|---|
P | D_ R_ | × | D_ rr |
↓ | |||
F1 | 3⁄8 | kNZiw76BruM/5Hg+yvTEyhKbLuU= | |
3⁄8 | 0Ea8S69N9GGkVuc+dYnzrQ== | ||
1⁄8 | /limvIMO1ryQra6x1ZVo1Q== | ||
1⁄8 | tKGNiMNuLyWixfp1YfEbGQ== |
The next step in solving the problem is to separate the cross into two single-locus crosses, looking at the inheritance of each trait by itself. Let's start with the texture characteristic.
First assemble the relevant information. In the table below fill in again what we know about the texture alleles for parents and progeny based solely on the information given directly in the question:
Generation | Genotypes | ||
---|---|---|---|
P | siZyXjF3/IwfAWZEKVDQPD79Qqk= | × | siZyXjF3/IwfAWZEKVDQPD79Qqk= |
↓ | |||
F1 | 3⁄8 | siZyXjF3/IwfAWZEKVDQPD79Qqk= | |
3⁄8 | siZyXjF3/IwfAWZEKVDQPD79Qqk= | ||
1⁄8 | 3TpmxSEeJfC4j8f6yqO+Ji/aDm8= | ||
1⁄8 | 3TpmxSEeJfC4j8f6yqO+Ji/aDm8= |
What ratio of dull to glossy fruit is observed in the progeny?
k7cilDdhoOvWsbxbpmtDqyJwHFNbU2OH4ao5rXPcTVssGVo14rRA1A== | dull (D_) |
cQTh6dRw7F+gk3hA2vA33ocV7Rujv/2DQN1/QIvybX6wdmUPbPeYUQ== | glossy (dd) |
In conclusion, then, we can conclude that the texture alleles for the two parents are eA9I1uaDoEhTML7qS5K/SQFWI8w= and eA9I1uaDoEhTML7qS5K/SQFWI8w=.
Now let's consider the color characteristic.
First assemble the relevant information. In the table below fill in again what we know about the color alleles for parents and progeny based solely on the information given directly in the question:
Generation | Genotypes | ||
---|---|---|---|
P | dPOKVwJqZomUvueilue47njt4hg= | × | yHzo4/FwVQSds8+X7hP2s5TIwlE= |
↓ | |||
F1 | 3⁄8 | dPOKVwJqZomUvueilue47njt4hg= | |
3⁄8 | yHzo4/FwVQSds8+X7hP2s5TIwlE= | ||
1⁄8 | dPOKVwJqZomUvueilue47njt4hg= | ||
1⁄8 | yHzo4/FwVQSds8+X7hP2s5TIwlE= |
What ratio of orange to cream fruit is observed in the progeny?
n3mV+x2Yz01eG/8kFcF6VaOj4Cz2WUA9KhSSko1Gk+3RgWDcvUYPPQ== | orange (R_) |
n3mV+x2Yz01eG/8kFcF6VaOj4Cz2WUA9KhSSko1Gk+3RgWDcvUYPPQ== | cream (rr) |
In conclusion, then, we can conclude that the texture alleles for the two parents are 6ALDYAJg1pTYHlwLWLM2SZ7N1es= and yHzo4/FwVQSds8+X7hP2s5TIwlE=.
Now put it all together and try filling in the whole table again:
Generation | Genotypes | ||
---|---|---|---|
P | 9j7AuVvXg3ivc2vjSXe1ag== | × | gIBNsGJrWXh7r45cVOe9HA== |
↓ | |||
F1 | SA3ZlRfQMIpF3Hps0RyE1Kj58k/2sn4OPCK/QaRkvVPDLIAy38X4ww== | QVaAmOeEgwWozc/fwHO75w== | |
SA3ZlRfQMIpF3Hps0RyE1Kj58k/2sn4OPCK/QaRkvVPDLIAy38X4ww== | 0Ea8S69N9GGkVuc+dYnzrQ== | ||
105MvCnUuqY/GMDSazpGJCkhiw9uKHbzVsMImvKNLJwv6Mde+GeMyA== | M/63sUNyCpQIH5fnT8HCqA== | ||
105MvCnUuqY/GMDSazpGJCkhiw9uKHbzVsMImvKNLJwv6Mde+GeMyA== | tKGNiMNuLyWixfp1YfEbGQ== |