Every plant has a seed, thanks to which it reproduces. What is the structure of apple, pumpkin and sunflower seeds? What are the similarities and differences between them, read the article.
The structure of an apple, pumpkin or sunflower seed
These plants are dicots. Outside, they are covered with a dense cover, which is called a peel. It protects the seed from damage, drying out, germs and premature germination. The seed has a small opening, which is called the seed entrance. It is necessary for the penetration of water inside. When the seeds germinate poorly, you need to check them. Semen inlet may be overgrown, you need to pick it up a little.
The structure of the seed of an apple tree, pumpkin and sunflower is similar. The seed embryo has two cotyledons located opposite each other. Between them is the germinal stem, on which the formation of rudimentary leaflets occurs directly in the embryo. The stem with leaves form a bud. She is the germ of the main shoot. The root is part of the seed. The embryo has an axis. At its top iskidney and symmetrically arranged cotyledons filled with cells with a large supply of food.
The fact is that the endosperm is absorbed by the embryo, the accumulation of nutrition now occurs in the latter. It will be used when the seed starts to germinate. The cotyledons are endowed with three conductive bundles that will be carried out to the surface of the soil. The lobes of the seed are the first modified leaves.
Similarities in the structure of seeds
The structure of apple and sunflower seeds is similar. It lies in the fact that in both plants the embryo has a root, a stalk, a kidney. They have two cotyledons, which contain a supply of food. The seeds are located internally in the fruit.
Pumpkin and sunflower are similar in that the cotyledons of these plants come to the soil surface in the same way. They have curved hypocotyl genu which help the cotyledons to come out.
Differences in seed structure
Apple and sunflower seeds differ, although they belong to the same plant species according to the structure of the seed. The difference is that the fruit of the apple tree is juicy and has many seeds. The sunflower is dry, with one seed.
If we consider the seeds of apple trees and pumpkins, their structure is different. Nutrients in the apple tree accumulate in the endosperm, and in the pumpkin - in the cotyledons. Seeds differ in size: apple - small, pumpkin - large.
Apple seed germination
First of all, you should consider in which region the fruit tree will grow. Accordingly seedsmust be taken from an apple grown in a given climate. For example, southern varieties will not survive in harsh climates.
The structure of the apple seed is such that it is not immediately able to germinate, as, indeed, most of the others. Seeds go through a stage of post-harvest ripening, it is called a dormant state. For pome crops, including apple trees, this period is long, taking more than a month.
The structure of the apple seed is arranged in such a way that when the cytoplasm in it is compacted, the life of the dry seed stops. It's hard to tell if it's alive or dead. Seeds are placed in warm water and provide access to oxygen. Sprouted seeds are alive, they are used for planting, swollen ones are dead, they are thrown away.
Depending on the growing conditions, the seeds are planted either immediately in the ground, or in prepared pots to obtain seedlings. Landing in the ground is carried out in regions with severe winters. The structure of the apple seed, the scheme of which is presented for review, allows the roots to germinate at low temperatures. They, trying to survive, will penetrate deep into the earth, which will not allow them to freeze during the frosty period. But for such a planting, an important condition is the deep occurrence of groundwater.
If the trees will grow in marshy soil, it is better to grow seedlings from seeds. The fact is that transplanting them into the ground, the roots will be damaged. The seedlings will not have the strength to grow deeper, so the plant will not start to rot.
What happens in a seed as it germinates?
The structure of the apple seed is such that water entering its cells contributes to swellingmembranes and cytoplasm, which contains a large number of glue-like substances (colloids). Swelling, they significantly increase in volume, the cytoplasm turns into a liquid. The process of oxidation (respiration) begins to occur in it, as a result of which water and carbon dioxide are released, and organic substances necessary for nutrition are also formed. In order for the process to continue, the seeds need a sufficient amount of carbohydrates or fats. They get these substances from stored starch and fats.
The structure of the apple seed, the photo of which is presented for review, is such that complex proteins - enzymes are formed in the cytoplasm. Acting as catalysts, they accelerate the biochemical processes in the cell. Moreover, the enzymes are not wasted. They convert the proteins stored in the seed into soluble substances: sugar, amino acids, fats, and others. Cells begin to divide and increase in size. This means that the seed is starting to germinate. When shoots appear, the plant will feed on substances contained in the soil and air.
Benefits of apple seeds
The main function of a small seed is reproduction. But, besides this, it benefits human he alth, as it contains many trace elements. First of all, apple seed is rich in natural iodine, which is fully absorbed by the body. In medicine, preventive measures against oncological diseases are carried out using vitamin B17, which in large quantitiescontained in the seed.
Oriental medicine uses the seed by applying it to the hands or feet in certain places. So specialists influence the work of internal organs. In cosmetology, crushed seeds are used to make masks and creams for facial skin rejuvenation.
In addition to benefits, the seed can also bring harm. It contains a compound that, under the influence of gastric juice, forms hydrocyanic acid, the strongest poison that causes poisoning. Therefore, apple seeds should not be consumed in large quantities.
Benefits of sunflower seeds
Seeds have a high biological value, are well absorbed and easily digested. They normalize the balance of acid and alkali in the body, the condition of the skin and mucous membranes. In large quantities, sunflower seeds contain minerals, carbohydrates, vitamins that dissolve fats, amino acids.
Vitamin E so much that fifty grams of seeds is enough to meet the daily needs of the body. This antioxidant has a powerful effect, prevents the development of a disease such as atherosclerosis, protects a person from radiation, including computer radiation.
Seeds are a high-calorie product: one hundred grams - seven hundred kilocalories. The high content of vitamin F prevents the destruction of nerve fibers, cell membranes and the accumulation of cholesterol.
There are also many useful substances in other products. The difference is thatin sunflower seeds, they persist longer, and year-round. Seeds do not spoil thanks to a strong shell.
Benefits of pumpkin seeds
All parts of melons have biological value. But the seeds are especially useful for the content of pumpkin seed oil. It contains a lot of acids: palmitic, oleic, stearic and linoleic.
Vitamin E, being a powerful antioxidant, prevents the development of many diseases: blood vessels and heart, atherosclerosis and hypertension, liver and kidneys, anemia, diabetes and oncology.
