Seed and friut development
Answers
Answer:
After pollination and fertilization, carpels develop into the fruit tissue we eat (ovary) and the seeds within (ovules). Fruit development is initiated by growth regulating hormones produced by developing seeds. ... Flowers with one carpel only require fertilization of one of the two ovules to produce fruit.
Explanation:
here is your answer :-)
Answer:
Many of us enjoy a refreshing slice of watermelon on a hot day, or have gone apple picking in the fall. Fruits are a major part of many people's diet and have been for millions of years. But what are fruits, really? And where do they come from? Today, we're going to look at the answers to these questions.
Although it might seem gross, fruits are actually ripened plant ovaries. Plants are non-motile, yet they reproduce sexually just like humans do. Plants don't engage in physical sex however. Rather, plants release sperm in the form of pollen, which is carried by wind and animals to flowers, which contain the plant egg cells inside an ovary. Seeds, and in some cases, fruits, develop from this fertilization. Let's look at the steps to make each in detail next.
Seed Development
Seeds are the reproductive units of plants, and as such, most seeds start with fertilization. Pollen grains travel from the stamen, the male reproductive organ of plants, to receptive flowers. Pollen grains that land on the pistil of the female reproductive structure germinate and form pollen tubes that travel through the style into the ovary.
Reproductive structures in angiosperms
flower
In the ovary, one pollen nuclei fuses with the egg cell to form a zygote. This cell will develop into the embryo that will ultimately germinate to become a new plant. But, in order to form a new plant, that single cell must divide. The zygote gets messages from surrounding tissues in the form of hormones. These chemicals promote the development of the embryo from the zygote. For example, cytokinins cause the zygote to go through cell division and auxins produced by the embryo cause cells to expand.
In angiosperms, or flowering plants, an additional pollen nuclei from the pollen tube fuses with two polar nuclei inside the ovary. This forms a triploid cell that will become the endosperm. The endosperm serves as a food source for the developing embryo. It contains carbohydrates, lipids, and proteins needed for growth of the embryo while it waits for germination.
However, not all angiosperms develop an endosperm. In orchids, the endosperm formation is suppressed, and in many cases, it is reduced and replaced by other food sources for the embryo. For example, beans use the cotyledon as a nutrition source, which will ultimately become leaves on the new seedlings.
The embryo and endosperm, if present, is encased in a seed coat. The seed coat is a hard outer layer of the ovary composed of layers called integuments. The main function of the seed coat is to protect the embryo.
Like human embryos need to be safely protected in the mother's uterus while they develop, similarly, plant embryos exist in a vulnerable stage in development. The seed coat prevents the embryo from drying out, or conversely being flooded by heavy precipitation. It also helps to regulate the temperature of the seed, preventing it from freezing in cold temperatures, or overheating during the heat of the day.
Fruit Development