1. You are conducting a screen for mutants in embryo pattern formation in tobacco - a plant that has an embryo and seedling structure and development that are very similar to those of Arabidopsis. Therefore, you are basing your screen on the one that was published by JÃ¼rgens and co-workers in 1991.

A. At what stage of snapdragon development would you screen for putative mutants in embryo pattern formation? Select only one option from the list below.
a. Zygote
b. Late heart-stage embryo
C. Mature embryo (i.e. seed)
d. Seedling
e. Flowering-stage plant

B. What pros and cons make screening at that stage of snapdragon development the best option? Select two pros and two cons from the lists below.
Pros
a. It filters out mutants in embryo pattern maintenance
b. It requires less work than screening at other stages
C. It is the first stage at which mutants in embryo pattern formation can be identified
d. It is the first stage of embryogenesis
e. It filters out embryo lethal mutants
Cons
a. It does not filter out mutants in embryo pattern maintenance
b. It requires more work than screening at other stages
C. It misses mutants in embryo pattern formation that do not survive embryogenesis
d. It filters out seedling lethal mutants
e. It does not filter out embryo lethal mutants

C. Which mutant generation would you screen to isolate recessive mutants in embryo pattern formation? Select only one option from the lists below.
a. M1
b. M2
C. M3
d. Either M1 or M2
e. M0

D. Why would you screen that generation? Select only one option from the lists below.
a. Because it is the first generation in which heritable mutations that affect embryo pattern formation, but not other processes, can be identified
b. Because it is the first generation in which effects of heritable mutations can be observed
c. Because it is the first generation in which effects of any mutation, whether or heritable non-heritable, can be observed
d. Because it is the first generation in which effects of recessive, but not of dominant, heritable mutations can be observed
e. None of the above

2. You have mutagenized Arabidopsis seeds with EMS, sown M1 M1 plants to maturity and harvested M1 plants individually. One genetically effective cell in the mature seeds, grown embryo that has given rise to M1 plant no. 2,457 contained a dominant mutation that the causes loss of green pigments. You SOW M2 seeds derived from M1 plant no. 2,457; what expected frequency of white M2 seedlings? Select only one option from the lists below.
a. 3 in 4
b. 3 in 8
C. 6 in 16
d. 9 in 16
e. 1 in 4

1. You are conducting a screen for mutants in embryo pattern format...