🌿 UNIT I - Outbreeding Devices 🌿
1. Outbreeding devices primarily promote
A. Self-pollination
B. Asexual reproduction
C. Cross-pollination
D. Vegetative propagation
Answer: C
Explanation: Outbreeding devices prevent self-pollination and encourage cross-pollination.
2. Dichogamy refers to
A. Presence of male and female flowers on same plant
B. Maturation of anther and stigma at different times
C. Spatial separation of sex organs
D. Genetic incompatibility
Answer: B
Explanation: In dichogamy, anther and stigma mature at different times.
3. Protandry is a type of
A. Herkogamy
B. Dichogamy
C. Self-incompatibility
D. Dioecy
Answer: B
Explanation: Protandry is a form of dichogamy where anthers mature first.
4. In protogyny
A. Anthers mature before stigma
B. Stigma matures before anthers
C. Both mature simultaneously
D. Flowers are unisexual
Answer: B
Explanation: Protogyny means stigma becomes receptive before pollen release.
5. Example of protandry is
A. Avocado
B. Sunflower
C. Maize
D. Pea
Answer: B
Explanation: Sunflower shows protandry.
6. Herkogamy prevents self-pollination by
A. Temporal separation
B. Genetic incompatibility
C. Physical barrier between anther and stigma
D. Male sterility
Answer: C
Explanation: Herkogamy is spatial separation of anther and stigma.
7. Which is an example of herkogamy?
A. Papaya
B. Salvia
C. Pea
D. Maize
Answer: B
Explanation: Salvia shows herkogamy due to lever mechanism.
8. Self-incompatibility is
A. Morphological
B. Physiological
C. Temporal
D. Mechanical
Answer: B
Explanation: It is a genetic/physiological mechanism preventing self-fertilization.
9. Self-incompatibility is controlled by
A. Environmental factors
B. Hormones
C. Genes
D. Pollinators
Answer: C
Explanation: It is genetically controlled.
10. Which condition prevents autogamy completely?
A. Dichogamy
B. Herkogamy
C. Unisexual flowers
D. Self-compatibility
Answer: C
Explanation: Unisexual flowers lack either anther or stigma.
11. In monoecious plants
A. Male and female flowers are on different plants
B. Flowers are bisexual
C. Male and female flowers are on same plant
D. Self-pollination is impossible
Answer: C
Explanation: Monoecious plants have separate male and female flowers on same plant.
12. Monoecious plants prevent
A. Autogamy
B. Geitonogamy
C. Xenogamy
D. Fertilization
Answer: A
Explanation: Autogamy is prevented due to unisexual flowers.
13. Example of monoecious plant
A. Papaya
B. Date palm
C. Castor
D. Mulberry
Answer: C
Explanation: Castor is monoecious.
14. Dioecious plants show
A. Autogamy
B. Geitonogamy
C. Xenogamy only
D. Self-pollination
Answer: C
Explanation: Male and female flowers are on different plants.
15. Example of dioecious plant
A. Mustard
B. Pea
C. Papaya
D. Sunflower
Answer: C
Explanation: Papaya is dioecious.
16. Which outbreeding device is MOST effective?
A. Dichogamy
B. Herkogamy
C. Self-incompatibility
D. Geitonogamy
Answer: C
Explanation: Self-incompatibility completely prevents self-fertilization.
17. Geitonogamy is
A. Genetically cross-pollination
B. Functionally self-pollination
C. Always prevented by outbreeding devices
D. Seen only in dioecious plants
Answer: B
Explanation: Pollen transfer occurs between flowers of same plant.
18. Which does NOT promote outbreeding?
A. Dichogamy
B. Herkogamy
C. Self-compatibility
D. Dioecy
Answer: C
Explanation: Self-compatibility allows self-pollination.
19. Cleistogamous flowers
A. Promote cross-pollination
B. Show self-incompatibility
C. Ensure autogamy
D. Are unisexual
Answer: C
Explanation: Cleistogamous flowers never open, ensuring self-pollination.
20. Which plant shows cleistogamy?
A. Wheat
B. Viola
C. Papaya
D. Salvia
Answer: B
Explanation: Viola shows cleistogamous flowers.
21. Outbreeding increases
A. Homozygosity
B. Genetic variability
C. Inbreeding depression
D. Uniformity
Answer: B
Explanation: Cross-pollination increases variation.
22. Inbreeding depression is avoided by
A. Autogamy
B. Outbreeding
C. Cleistogamy
D. Self-compatibility
Answer: B
Explanation: Outbreeding introduces new gene combinations.
23. Which device involves time difference?
A. Herkogamy
B. Dichogamy
C. Dioecy
D. Self-incompatibility
Answer: B
Explanation: Dichogamy is temporal separation.
24. Which involves space separation?
A. Protogyny
B. Protandry
C. Herkogamy
D. Dichogamy
Answer: C
Explanation: Herkogamy is spatial separation.
25. Which is NOT an outbreeding device?
A. Dichogamy
B. Herkogamy
C. Cleistogamy
D. Dioecy
Answer: C
Explanation: Cleistogamy promotes self-pollination.
26. Outbreeding devices are adaptations to
A. Ensure fertilization
B. Prevent pollen loss
C. Promote genetic diversity
D. Attract pollinators
Answer: C
27. Self-incompatibility occurs at
A. Pollination stage
B. Fertilization stage
C. Seed formation
D. Fruit formation
Answer: A
28. In self-incompatibility, pollen fails to
A. Germinate
B. Reach stigma
C. Form anther
D. Disperse
Answer: A
29. Which plant shows both chasmogamous and cleistogamous flowers?
A. Viola
B. Papaya
C. Maize
D. Wheat
Answer: A
30. Chasmogamous flowers
A. Never open
B. Promote autogamy only
C. Can show cross-pollination
D. Are unisexual
Answer: C
31. Genetic recombination is maximum in
A. Autogamy
B. Geitonogamy
C. Xenogamy
D. Cleistogamy
Answer: C
32. Which ensures compulsory cross-pollination?
A. Monoecy
B. Dioecy
C. Dichogamy
D. Herkogamy
Answer: B
33. Geitonogamy is prevented in
A. Bisexual flowers
B. Monoecious plants
C. Dioecious plants
D. Cleistogamous flowers
Answer: C
34. Outbreeding devices are absent in
A. Wheat
B. Papaya
C. Castor
D. Sunflower
Answer: A
35. Which flower ensures seed set even in absence of pollinators?
A. Chasmogamous
B. Cleistogamous
C. Unisexual
D. Dioecious
Answer: B
36. Outbreeding devices evolved to avoid
A. Pollination
B. Fertilization
C. Inbreeding
D. Seed dispersal
Answer: C
37. In Salvia, pollination mechanism involves
A. Dichogamy
B. Herkogamy
C. Self-incompatibility
D. Dioecy
Answer: B
38. Which is genetically controlled?
A. Herkogamy
B. Dichogamy
C. Self-incompatibility
D. Dioecy
Answer: C
39. Autogamy occurs in
A. Dioecious plants
B. Cleistogamous flowers
C. Unisexual flowers
D. Monoecious plants
Answer: B
40. Outbreeding devices increase
A. Homozygosity
B. Inbreeding depression
C. Hybrid vigor
D. Genetic purity
Answer: C
41. Which flower type always ensures autogamy?
A. Chasmogamous
B. Cleistogamous
C. Unisexual
D. Dioecious
Answer: B
42. Example of plant showing protogyny
A. Sunflower
B. Avocado
C. Pea
D. Wheat
Answer: B
43. Which is NOT temporal separation?
A. Protandry
B. Protogyny
C. Herkogamy
D. Dichogamy
Answer: C
44. Outbreeding devices are absent in
A. Cleistogamous flowers
B. Dioecious plants
C. Self-incompatible plants
D. Herkogamous flowers
Answer: A
45. Which is functionally cross-pollination but genetically self-pollination?
A. Xenogamy
B. Autogamy
C. Geitonogamy
D. Dioecy
Answer: C
46. In maize, pollination is
A. Autogamous
B. Xenogamous
C. Cleistogamous
D. Self-incompatible
Answer: B
47. Self-incompatibility is absent in
A. Brassica
B. Potato
C. Tobacco
D. Wheat
Answer: D
48. Which promotes genetic variability the MOST?
A. Autogamy
B. Cleistogamy
C. Xenogamy
D. Geitonogamy
Answer: C
49. Outbreeding devices prevent
A. Pollination
B. Fertilization
C. Self-fertilization
D. Seed formation
Answer: C
50. CBSE considers outbreeding devices as adaptations to
A. Ensure survival
B. Increase yield
C. Promote cross-pollination
D. Attract insects
Answer: C
