The flower is the reproductive organ of flowering plants and plays a central role in sexual reproduction. It consists of various parts, such as the sepals, petals, stamens, and pistil. The stamen is the male reproductive organ, consisting of the anther and filament, while the pistil is the female reproductive organ, consisting of the stigma, style, and ovary. Pollination is the process by which pollen grains from the anther reach the stigma, facilitating fertilization.
What is the primary function of the anther in a flower?
Answer: B) To produce pollen grains
Which part of the flower serves as the female reproductive organ?
Answer: B) Pistil
The process of pollination involves the transfer of pollen from the anther to which part of the flower?
Answer: A) Stigma
Which of the following is true about the ovary in the flower?
Answer: B) It contains ovules that develop into seeds after fertilization
Pollination is a crucial step in the sexual reproduction of flowering plants, and it can occur through various mechanisms, including wind, water, insects, birds, and animals. For instance, in many angiosperms, flowers are pollinated by insects, which transfer pollen from one flower to another as they move from plant to plant in search of nectar. These plants are often brightly colored and produce pleasant scents to attract pollinators. In contrast, wind-pollinated plants, like grasses, produce lightweight pollen grains that are carried by air currents.
Which of the following is a characteristic feature of insect-pollinated flowers?
Answer: B) They have large, brightly colored petals and a strong fragrance
What is the main function of the pollen grain in the process of pollination?
Answer: C) To carry male gametes to the stigma
In wind-pollinated plants, how are the pollen grains adapted to be carried by the wind?
Answer: A) They are small and lightweight
Which of the following is NOT a mechanism of pollination?
Answer: C) Fertilization
After successful pollination, fertilization takes place within the ovule, leading to the formation of a zygote. The process begins when a pollen grain lands on the stigma, and the pollen tube grows down through the style into the ovary. The male gametes travel through the pollen tube, and one fuses with the egg cell to form the zygote. This fertilization process leads to the formation of seeds that can develop into new plants.
After pollination, where does the pollen grain germinate?
Answer: C) On the stigma
The pollen tube grows from the pollen grain to the ovule through which part of the flower?
Answer: B) Style
What is formed after the fusion of a male gamete with the egg cell during fertilization?
Answer: A) Zygote
Which part of the flower contains the ovule where fertilization occurs?
Answer: B) Pistil
Double fertilization is a unique feature of angiosperms (flowering plants) where two fertilization events occur within the ovule. One male gamete fuses with the egg cell to form the zygote, while the other male gamete fuses with two polar nuclei to form the triploid endosperm. The zygote develops into the embryo, while the endosperm serves as the food reserve for the developing seed.
What is the outcome of the second fertilization event in double fertilization?
Answer: B) Formation of the endosperm
Double fertilization results in the formation of:
Answer: A) Zygote and endosperm
The triploid endosperm is formed by the fusion of:
Answer: B) One male gamete and two polar nuclei
What is the primary function of the endosperm formed during fertilization?
Answer: B) To provide nutrients to the developing embryo
After fertilization, the ovule undergoes significant changes to develop into a seed. The zygote develops into an embryo, and the ovule matures into a seed. The ovary surrounding the ovule develops into the fruit. The seed contains an embryo, a seed coat, and a food reserve (endosperm), which are essential for the growth of a new plant when the seed germinates.
After fertilization, what does the ovary develop into?
Answer: A) Fruit
What is the function of the seed coat?
Answer: B) To protect the seed from mechanical damage and dehydration
Which part of the seed contains the stored food reserve?
Answer: C) Endosperm
What does the zygote develop into after fertilization?
Answer: B) Embryo