Outbreeding Devices, Definition, Reasons, Examples and MCQs

Outbreeding devices are biological mechanisms that encourage crossbreeding and prevent inbreeding within populations. Inbreeding, or mating between closely related organisms, can lead to genetic defects and reduced fitness in offspring. Outbreeding devices ensure that organisms mate with others from different genetic backgrounds, promoting genetic diversity and increasing the chances of survival and adaptation. These mechanisms are an important part of the study of reproduction and genetics, which is essential for the NEET Exam .

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Definition of Outbreeding Devices

Reasons for Outbreeding

• Genetic Diversity: Outbreeding increases genetic diversity, which makes populations more resilient to diseases, environmental changes, and other challenges.
• Reduction of Inbreeding Depression: Inbreeding can result in harmful genetic traits being passed down, leading to inbreeding depression, where the offspring may be weak or less fit for survival. Outbreeding helps prevent this.
• Better Adaptation: Organisms that undergo outbreeding are more likely to adapt to changes in their environment because they have a wider range of genetic traits.
• Increased Fertility and Survival: Crossbreeding often leads to healthier offspring, with better chances of survival and reproduction.

Examples of Outbreeding Devices

Dicliny (Unisexuality) Unisexual Flowers

• Monoecious: In monoecious species, both male and female flowers are present on the same plant. For example, plants like castor and maize have separate male and female flowers, preventing autogamy (self-fertilization) but not geitonogamy (fertilization between different flowers on the same plant).
• Dioecious: In dioecious species, male and female flowers are found on separate plants. This condition prevents both autogamy and geitonogamy, ensuring that crossbreeding occurs only between different plants of the same species. Examples include holly and kiwifruit.

Dichogamy

Heterostyly

Self-Incompatibility

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MCQs of Outbreeding Devices

Q1. The device to prevent inbreeding is;

1. Self-incompatibility
2. Autogamy
3. Self-pollination
4. All of these

Q2. The majority of flowering plants produce _____A____ flowers and pollen grains are likely to come in contact with the stigma of the _____B____ flower:

1. A - Hermaphrodite, B - same
2. A - Unisexual flower, B - different
3. A - Hermaphrodite, B - different
4. A - Unisexual flower, B - same

Q3. Stigma matures earlier so that it gets pollinated before the anthers of the same flower develop pollen grains;

1. Herkogamy
2. Protogyny
3. Self incompatibility
4. Unisexuality

Also Check:

• Free Toppers Notes for NEET
• Free NEET Lectures by PW Faculties
• NEET Study Material, Free Sample Papers, Book, Toppers Notes, PYQs

Answers of MCQs of Outbreeding Devices