ICSE – Grade 9 – Biology – Ch 04 – QA

Case Study 1

Case:
 A farmer observes that the flowers on his plants are failing to produce fruits. He suspects that there is a problem with pollination. What could be the reason for this, and what steps should the farmer take to improve pollination?

Answer:
 The problem could be due to the absence of pollinators like insects or birds. To improve pollination, the farmer can plant more pollinator-friendly plants, use natural insecticides to avoid harming pollinators, and ensure there is a variety of flowers to attract different pollinators.

Case Study 2

Case:
 A student is studying a flower in the laboratory and identifies the parts of the flower: petals, stamens, style, and ovary. The student is curious about which part of the flower is responsible for producing the pollen.

Answer:
 The part of the flower responsible for producing pollen is the anther, which is part of the stamen (the male reproductive organ of the flower).

Case Study 3

Case:
 A florist is cultivating a plant with bright, colorful flowers, but despite many visits from bees, the plant isn’t producing seeds. What is likely the cause, and how can this be resolved?

Answer:
 The plant may be sterile, meaning it lacks the ability to produce seeds. This could be due to the absence of a female reproductive organ or a lack of ovules. The florist may need to cultivate plants with both male and female organs or consider cross-pollination from another plant species.

Case Study 4

Case:
 A botanist is conducting an experiment to investigate the effects of wind on pollination. She uses two groups of flowers—one group that depends on wind pollination and another group that depends on insects. What might the botanist conclude after the experiment?

Answer:
 The botanist may conclude that wind-pollinated flowers typically have lightweight, non-sticky pollen and are designed for efficient dispersal by the wind, while insect-pollinated flowers tend to have larger, stickier pollen grains that attract insects.

Case Study 5

Case:
 A farmer notices that some plants in his garden have both male and female reproductive organs on the same flower. What type of flower is this, and what does it mean for pollination?

Answer:
 This type of flower is a bisexual flower, meaning it has both male (stamens) and female (pistils) reproductive organs. This ensures that pollination can occur within the same flower or with another flower on the same plant.

Case Study 6

Case:
 A gardener is planting a variety of flowers that need cross-pollination. What could the gardener do to ensure successful pollination?

Answer:
 To ensure successful cross-pollination, the gardener could plant a variety of flowers close together to facilitate pollen transfer between different plants. Additionally, ensuring the presence of pollinators like bees, butterflies, and birds will help improve cross-pollination.

Case Study 7

Case:
 During a dissection of a flower, a student notices the ovules inside the ovary. The student wonders what role the ovules play in the reproduction of the plant.

Answer:
 The ovules are the female gametes of the plant. After fertilization by the male gamete (sperm), the ovules develop into seeds, which later grow into new plants.

Case Study 8

Case:
 A farmer decides to use artificial pollination to increase the production of hybrid plants. What method should the farmer use, and what is the purpose of artificial pollination?

Answer:
 The farmer can use hand-pollination, where pollen from one plant is manually transferred to the stigma of another plant. The purpose of artificial pollination is to ensure controlled breeding and the production of desired hybrid plants with improved traits.

Case Study 9

Case:
 A student is studying a plant that has separate male and female flowers on different plants. What is the term used to describe such plants?

Answer:
 Plants that have separate male and female flowers on different plants are known as dioecious plants. This means that each plant is either male or female.

Case Study 10

Case:
 A researcher is studying flowers that bloom at night to attract nocturnal pollinators like moths. What adaptations might these flowers have?

Answer:
 These flowers may have light-colored petals to attract nocturnal pollinators, a strong fragrance to make them noticeable at night, and may be larger in size for easier access by moths.

Case Study 11

Case:
 A student is examining a flower and notices a sticky substance on the stigmatic surface. What is the purpose of this sticky substance?

Answer:
 The sticky substance on the stigmatic surface is there to trap pollen grains during pollination. It helps ensure that the pollen can germinate and fertilize the ovule.

Case Study 12

Case:
 In a greenhouse, a scientist is trying to encourage self-pollination in plants. What conditions should the scientist control to achieve this?

Answer:
 To encourage self-pollination, the scientist should ensure that the plants have both male and female reproductive organs on the same flower (i.e., bisexual flowers). The flowers should be isolated from other plant species to avoid cross-pollination.

Case Study 13

Case:
 A biologist notices that some flowers have brightly colored petals. What could be the biological advantage of this trait?

Answer:
 The brightly colored petals attract pollinators like bees, butterflies, and birds. This helps in transferring pollen, aiding in the process of pollination.

Case Study 14

Case:
 A researcher is studying a plant that undergoes vegetative propagation. What part of the plant is likely responsible for this type of reproduction?

Answer:
 Vegetative propagation involves the growth of new plants from non-reproductive parts like roots, stems, or leaves. This method does not involve seeds or flowers.

Case Study 15

Case:
 A student is studying a flower’s development. After fertilization, what happens to the ovary and ovules?

Answer:
 After fertilization, the ovary develops into a fruit, and the ovules inside the ovary become seeds.

Case Study 16

Case:
 A flower has large, bright-colored petals and produces a sweet fragrance. Which type of pollination is most likely in this case?

Answer:
 This flower most likely undergoes insect pollination (entomophily), as the large, colorful petals and sweet fragrance are characteristics that attract insects like bees and butterflies.

Case Study 17

Case:
 A plant has staminate flowers (male flowers) and pistillate flowers (female flowers) on separate plants. What kind of plant is this?

Answer:
 This type of plant is called a dioecious plant, where male and female flowers are found on separate plants, requiring cross-pollination.

Case Study 18

Case:
 A gardener notices that flowers on his plants are failing to attract pollinators, and he decides to plant additional plants that attract bees. Why would this help?

Answer:
 Bees are important pollinators, and by planting more bee-attracting flowers, the gardener increases the chances of cross-pollination and improves the plant’s ability to produce seeds.

Case Study 19

Case:
 A student is observing a flower and is curious about the role of nectar in the pollination process. What is the significance of nectar?

Answer:
 Nectar serves as a food source for pollinators like bees and butterflies. As the pollinators visit the flower for nectar, they inadvertently transfer pollen, thus aiding in pollination.

Case Study 20

Case:
 A researcher is studying a flower with both male and female parts in the same flower. What is this flower classified as, and what type of pollination is it likely to undergo?

Answer:
 This flower is classified as a bisexual flower, and it is likely to undergo self-pollination or cross-pollination depending on the presence of other flowers.