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Name: 1. the site of production of a pollen grain and 2 - Leaving Cert Biology - Question 14 - 2014
Question 14
Name: 1. the site of production of a pollen grain and 2. the structure on which it must land to complete pollination. Name two methods of cross pollination. Many ... show full transcript
Worked Solution & Example Answer:Name: 1. the site of production of a pollen grain and 2 - Leaving Cert Biology - Question 14 - 2014
Step 1
the site of production of a pollen grain and the structure on which it must land to complete pollination.
Answer
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The site of production of a pollen grain is the anther, which is part of the stamen in flowering plants.
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The structure on which it must land to complete pollination is the stigma of the flower.
Step 2
Step 3
Suggest how such plants could benefit from this.
Answer
Plants that prevent self-pollination benefit by ensuring greater genetic variation within their population. This variation can improve resilience to diseases and environmental changes, as well as prevent the negative effects of inbreeding.
Step 4
Describe in detail the events that follow the arrival of a pollen grain at the destination referred to in (i), up to and including fertilisation.
Answer
When a pollen grain arrives at the stigma, it germinates and forms a pollen tube. This tube grows down through the style toward the ovary, where the ovules are located.
Inside the pollen grain, the generative nucleus divides by mitosis to produce two male gametes. As the pollen tube enters the ovule, one of these gametes fertilises the female egg cell, while the other fertilises the polar nuclei, leading to the formation of the endosperm, which nourishes the developing embryo.
Step 5