7. Maternal effect: In Limnaea snail cats, R makes right coiled shells; r makes left coiled shells, and R is dominant to r, as we discussed in class. Even though these can be hermaphrodites, and act either as mom or dad, we'll just pretend they are male or female. A Rr male marries an rr female. a) What are the genotypes of their offspring and in what ratio? b) What are the phenotypes of their offspring and in what ratio?

7. Maternal effect: In Limnaea snail cats, R makes right coiled shells; r makes left coiled shells, and R is dominant to r, as we discussed in class. Even though these can be hermaphrodites, and act either as mom or dad, we'll just pretend they are male or female. A Rr male marries an rr female. a) What are the genotypes of their offspring and in what ratio? b) What are the phenotypes of their offspring and in what ratio?

Biology 2e

2nd Edition

ISBN:9781947172517

Author:Matthew Douglas, Jung Choi, Mary Ann Clark

Publisher:Matthew Douglas, Jung Choi, Mary Ann Clark

Chapter43: Animal Reproduction And Development

Section: Chapter Questions

Problem 34CTQ: Why would paired external fertilization be preferable to group spawning?

See similar textbooks

Similar questions

List and briefly describe the three processes that lead to variation in offspring with the same parents.
Explain what a cline is and provide examples.
How would mutations that completely ablate the function of the androgen receptor impact the phenotypic development of humans with XY chromosomes? Patients would appear phenotypically female Patients would appear phenotypically male with underdeveloped secondary sex characteristics Patients would appear phenotypically male, but cannot produce sperm Patients would express both male and female secondary sex characteristics.
Can conjoined (Siamese) twins be dizygotic twins in light of the theory that conjoined twins result from incomplete division of the embryo?
Which reproductive combination produces hybrids? when individuals of the same species in different geographical areas reproduce when any two individuals sharing the same habitat reproduce when members of closely related species reproduce when offspring of the same parents reproduce
Explain why sexual reproduction is beneficial to a population but can be detrimental to an individual offspring.
Why is sexual reproduction useful if only half the animals can produce offspring and two separate cells must be combined to form a third?
How do organisms with haploid-dominant life cycles ensure continued genetic diversification in offspring without using a meiotic process to make gametes?
Birth Defects and Multiple Births A woman who carries multiple offspring at the same time increases the risk of some birth defects. FIGURE 42.18 shows the results of Yiwei Tang's study of birth defects reported in Florida from 1W6 to 2000. Tang compared the incidence of various defects among single and multiple births. She calculated the relative risk for each type of defect based on type of birth, and corrected for other differences that might increase risk such as maternal age, income, race, and medical care during pregnancy. A relative risk of less than 1 means that multiple births pose less risk of that defect occurring. A relative risk greater than 1 means multiples are more likely to have a defect. FIGURE 42.18 Prevalence, per 10,000 live births, of various types of birth defects among multiple aria single births. Relative risk for each defect is given after researches adjusted for the motor's age, race, previous adverse pregnancy experience, education, Medicaid participation during pregnancy, as well as the infant's sex and number of siblings. 4. Does a multiple pregnancy increase the relative risk of chromosomal defects in offspring?
External fertilization occurs in which type of environment? aquatic forested savanna steppe
Why are polyandrous mating systems more rare than polygynous matings? Only males are capable of multiple rounds of reproduction within a single breeding season Only females care for the young Females usually experience more intrasexual selection pressure than males Females usually devote more energy to offspring production and development.
The end product of cleavage is a __________. a. gamete b. blastula c. gastrula d. zygote