The Flower-2 (Morphology Test) - Grade 10

Fertilization is the biological process where male and female gametes fuse to form a zygote. This is the correct term for the fusion of reproductive cells in sexual reproduction.

Pollination is the transfer of pollen grains from the anther (male part) to the stigma (female part) of a flower. This is the correct botanical term for this process, which is a prerequisite for fertilization in plants.

Self sterility is a physiological mechanism where pollen from the anther cannot germinate on the stigma of the same flower. This prevents self-pollination and promotes cross-pollination, increasing genetic diversity.

Entomophilous plants are those pollinated by insects. The prefix 'entomo-' refers to insects, and '-philous' means loving. These plants have evolved features like bright colors, nectar, and scent to attract insect pollinators.

Cross pollination is the transfer of pollen grains from the anthers of one plant to the stigma of a flower on a different plant of the same species. This promotes genetic variation and is contrasted with self-pollination.

Anemophilous plants are wind-pollinated. The prefix 'anemo-' refers to wind. These plants produce lightweight, smooth pollen grains, sometimes with wing-like structures (air sacs) that help them float on air currents for long distances.

Hydrophilous plants are adapted for water pollination. Their pollen grains have specific gravity equal to water, allowing them to float and be carried by water currents to reach stigmas. Ornithophilous plants are bird-pollinated, entomophilous are insect-pollinated, and anemophilous are wind-pollinated.

Pistillate flowers contain only female reproductive organs (pistil), which includes the stigma, style, and ovary. Gynoecium refers to the collective female parts, but pistillate specifically describes flowers with only these female structures. Perianth is the non-reproductive outer parts, and androecium refers to male structures.

Ornithophilous (bird-pollinated) plants produce abundant nectar in specialized structures like pitcher-shaped nectaries to attract birds. Hydrophilous plants are water-pollinated, entomophilous are insect-pollinated, and anemophilous are wind-pollinated.

Self-pollination occurs when pollen from an anther fertilizes the stigma of either the same flower (autogamy) or another flower on the same plant (geitonogamy). Cross pollination involves different plants, fertilization is the fusion of gametes, and pollination is the broader process.

Herkogamy is a structural mechanism where physical barriers (like unequal stamen and stigma positions or floral architecture) prevent self-pollination. Protogyny and protandry are temporal mechanisms (timing differences), while heterostyly involves different style lengths in different flowers.

The generative nucleus in the pollen tube divides mitotically to form two male gametes, which move toward the tube tip. The tube nucleus guides tube growth but doesn't form gametes. Zygote and embryo form after fertilization.

The fusion of two polar nuclei (in the embryo sac) with one male gamete forms the triploid (3n) endosperm nucleus, which develops into nutritive endosperm tissue. The zygote forms from egg + male gamete, while tube and generative nuclei are pollen structures.

One male gamete fuses with the egg cell to form the diploid zygote (2n), which develops into the embryo. The other male gamete fuses with polar nuclei to form the endosperm nucleus. Tube and generative nuclei are pollen structures, not fertilization products.

After fertilization, the zygote develops a cell wall and becomes the oospore, a resting stage that then develops into the embryo. The ovule develops into the seed, not the zygote itself. Calyx and corolla are floral whorls.

The oospore develops through mitotic divisions to form the embryo (the immature sporophyte). The ovule develops into the seed (containing the embryo), and the ovary develops into the fruit. Endosperm is the nutritive tissue.

Angiosperms exhibit double fertilization: one male gamete fuses with the egg to form the zygote, and another fuses with polar nuclei to form the endosperm nucleus. This unique process is characteristic of flowering plants.

Homogamy refers to the simultaneous maturation of anthers and stigma in the same flower, making self-pollination possible. Herkogamy is a physical barrier, protandry/protogy are timing differences where one matures first, and dichogamy is the general term for staggered maturation.

Unisexuality refers to the condition where male and female flowers are borne on separate plants, a phenomenon known as dioecy. This prevents self-pollination and promotes cross-pollination. Dichogamy refers to timing differences in maturation, not spatial separation.

Protandry is a form of dichogamy where the anthers (male parts) mature and release pollen before the stigma (female part) is receptive. This temporal separation prevents self-pollination. Protogyny is the reverse condition.

Protogyny is the condition where the stigma matures and becomes receptive before the anthers have matured and released pollen. This temporal sequence prevents self-pollination within the same flower. Protandry is the opposite condition.

The tube nucleus remains at the growing tip of the pollen tube as it elongates toward the ovule and eventually disintegrates. The generative nucleus divides to form two sperm cells. The tube nucleus helps guide pollen tube growth but is not involved in fertilization.

Artificial pollination (also called hand pollination or controlled pollination) is a technique used by plant breeders to deliberately cross-pollinate specific plants to create new varieties with desired traits. Post-fertilization and double fertilization are biological processes, not breeding practices.

Triple fusion refers to the fusion of one male gamete with the two polar nuclei in the embryo sac, forming a triploid primary endosperm nucleus. This is the second fertilization event in double fertilization. The zygote forms from the first male gamete fusing with the egg cell.

After fertilization, the ovule develops into the seed which contains the embryo and stored food. The ovary develops into the fruit, not the ovule. The embryo forms from the zygote, and endosperm (not endoperm) develops from triple fusion.