What is the escape of potatoes. Overground and underground modifications of the shoots
Prove that a tuber is a modified underground shoot
- He has modified leaves and stem)))
- ornevische, tuber,
Peculiar underground storerooms have perennial herbaceous plants. The aboveground parts of these plants die off every autumn. In the soil there are roots and modified underground shoots. They do not look like ordinary above ground. It is in these modified shoots that the reserves of organic substances are deposited for the winter. Modified shoots are rhizomes, tubers and bulbs.
If you dig up the rhizome of any plant from the ground, you can see that it looks like a root. But the rhizome, as in above-ground shoots, has apical and axillary buds, as well as membranous scales - modified leaves. Additional roots grow from the rhizome.
In the spring, young above-ground shoots develop from the apical or axillary buds of the rhizome. They use the nutrients deposited in the rhizome in the fall. If a piece of rhizome with a bud and adventitious roots is planted in the soil, a new, independently living plant will develop.
Tubers are characteristic of few plants. Underground shoots, on the tops of which tubers develop, grow from the bases of the above-ground stems; these shoots are called stolons. Tubers are apical thickenings of stolons.
Tuber has short internodes; it does not contain chlorophyll, but when exposed to light it may turn green. Consider the potato tuber. On its surface in the grooves of 2-3 located kidneys, or eyes. Eyes more on the part of the tuber, which is called the tip. The opposite side - the base - the tuber is connected to the stolon. The structure of the tuber convinces that the tuber is a modified underground shoot.
From the leaves of the potato through the stems in the stolons constantly flowing organic matter and in the form of starch are deposited in the tops. The tops of stolons grow, thicken, and by the autumn turn into large tubers.
"Biology. Bacteria, fungi, plants. Grade 6". V.V. Beekeeper
Overground and underground modifications of the shoots
Question 1. What modified underground shoots do you know? Name the plants with rhizome, tuber, bulb.
Tubers are formed as terminal thickenings of underground shoots - stolons. Stolons grow from the base of the above-ground stalks. Tubers develop as a result of the thickening of the apical buds of stolons (potatoes, crested birds, and earth pears). On them are groups of buds, which are called ocelli. Tubers are used for vegetative propagation.
The bulb is an underground shortened modified shoot. The stem of the bulb forms the bottom. Leaves or scales are attached to the Donets. External scales are usually dry, they perform a protective function. They cover sochi scales, in which nutrients and water are deposited. At the bottom there is an apical bud, from which above-ground leaves and flowering arrow develop. Adventitious roots develop on the lower part of the base. Bulbs are characteristic of perennial plants (lilies, tulips, onions, garlic, narcissus, wild onions, etc.). With the help of bulbs, plants can multiply vegetatively.
The rhizome is also an underground shoot that looks like a root. The rhizome is scaly leaves, in the axils of which are axillary buds. Additional roots form on the rhizome, and lateral branches of the rhizome and above-ground shoots develop from the axillary buds. Rhizomes are found in perennial herbaceous plants (horsetails, ferns, nettle, lily of the valley, cereals, etc.). Rhizome is an organ of vegetative propagation.
Question 2. How to distinguish rhizome from the root?
In appearance, the rhizome resembles a root, but differs from it in the presence of scale-like leaves, leaf traces (scars from fallen leaves), buds, and the absence of a root cap.
Question 3. How does potato tuber develop?
From the leaves of the potato through the stems in the underground shoots (stolons) constantly flowing organic matter and in the form of starch deposited in the tops of stolons. The tops of stolons grow, thicken, and by the autumn turn into large tubers.
Question 4. Why potato tuber should be considered an escape?
A potato tuber should be considered an escape because it, like an escape, is formed by a stem that performs the storage function, has buds (eyes) and scaly leaves.
Question 5. What is the structure of the bulb?
At the bottom of the bulb, for example onions, located almost flat stem - bottom. Adventitious roots and modified leaves (scales) depart from the bottom. Outer leaves - scales - dry and leathery, they perform a protective function; internal - fleshy and juicy, they are deposited nutrients. In the axils of the scales there are axillary buds.
Question 6. How to prove that the rhizome and the bulb - it is modified shoots?
Externally, the rhizome resembles the root, but, like a ground run, it has apical and axillary buds, as well as membranous scales — modified leaves. Thus, the rhizome has a stem (the axial part of the rhizome, buds and leaves (membranous scales), i.e., that is characteristic of the shoot. At the bulb, we can also see all parts of the shoot: the stem (bottom of the bulb), leaves (dry and succulent scales) and buds (between scales). This confirms that the rhizome and the bulb are modified shoots.
Potatoes belong to the family of nightshade:
- in the flower it has 5 conjoined sepals, 5 conjoined petals, 5 stamens, 1 pistil.
- in all parts of the plant contains toxic substance solanine.
Potatoes are poisonous berries. Potato tubers are modified shoots. Proof of:
- on tubers there are remains of leaves (brows) and axillary buds (eyes);
- in the light, the tubers are turning green, because leucoplasts turn into chloroplasts (after that the content of solanine in tubers increases dramatically and they become poisonous).
Tubers grow on modified underground shoots (stolons), departing from the stem. When hilling, the lower part of the stem of potatoes is poured with earth, because of this, the number of stolons increases, as well as adventitious roots. In addition, when hilling, weeds are destroyed and the soil is loosened (more air flows to the roots).
Most of the dry matter of potato tubers is starch. After long-term storage of tubers, their weight decreases, because the starch is gradually converted into glucose, glucose is oxidized, the energy necessary for the life of the tuber is obtained, as well as water and carbon dioxide, which evaporate.
After cooking, the potatoes become crumbly because the pectin-like substances connecting the cells are destroyed.
148-1. Potato tubers are formed on
A) lateral roots
B) adventitious roots
C) modified underground shoots - stolons
D) modified underground shoots - rhizomes
148-2. What is the name of the organ shown in the photograph of the angiosperm plant?
A) rhizome
B) onion
C) tuber
D) root
148-3. Potato seeds are the result of
A) root development
B) fertilization
C) the formation of tubers
D) vegetative propagation
Question 3. How does potato tuber develop?
From the leaves of the potato through the stems in the underground shoots (stolons) constantly flowing organic matter and in the form of starch deposited in the tops of stolons. The tops of stolons grow, thicken, and by the autumn turn into large tubers.
Question 4. Why potato tuber should be considered an escape?
Question 5. What is the structure of the bulb?
In the lower part of the bulb, such as onions, is located almost flat stem - bottom. Adventitious roots and modified leaves (scales) depart from the bottom. Outer leaves - scales - dry and leathery, they perform a protective function; internal - fleshy and juicy, they are deposited nutrients. In the axils of the scales there are axillary buds.
Why potato is a modified shoot
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How to prove that a tuber is a modified shoot
An escape is called a stem with leaves and buds. The stem is its axial part, the leaves - the side. The latter develop in nodes, the areas between which are called interstices.
Instruction
- The stem creates the frame of the plant, brings the leaves to the light and conducts water, mineral and organic matter. Nutrients may be stored there. On the stem not only leaves develop, but also flowers, as well as fruits with seeds. The main functions of the leaves are photosynthesis, evaporation of water and gas exchange with the environment.
- Modified shoots perform additional functions in the life of the plant. A number of perennial herbaceous plants have peculiar pantries under the ground. They are modified underground shoots - rhizomes, bulbs, tubers. Elevated parts die annually by autumn.
- In the rhizomes, bulbs and tubers spare nutrients are deposited for the winter. The rhizome is present in nettle, lily of the valley, iris, wheatgrass, aspidistra. Outwardly, it is similar to the root, but it has apical and axillary buds, and membranous scales play the role of modified leaves. Additional roots grow from the rhizome, and the apical and axillary buds give rise to young above-ground shoots. In this case, the plant uses substances stored in the fall.
- With the help of rhizome, as well as other modified shoots can be vegetative propagation of plants. By planting a part of the rhizome with a bud and roots into the soil, you can get a new, independent plant organism. Some ornamental plants propagated by rhizome fragmentation.
- Tubers can be observed in potatoes, Jerusalem artichoke (earthen pear), and crested hen. From the bases of the aboveground stems, underground shoots grow, called stolons. The apical thickenings of the latter are tubers.
- On the upper surface of the tuber, you can see the eyes - it is modified buds. The underside of the tuber is connected with an underground shoot. Like the stem, the tuber in cross section can be divided into several characteristic layers: cork, phloem, wood and pith. All these signs prove that the tuber is a modified shoot.
- Nutrients from the leaves continuously flow to the tubers through the stems and stolons. Thus, these tops of underground shoots are saturated with starch and increase in size.
- The bulbs are characteristic of tulips, lilies, onions, wild goose onions, daffodils. The lower part of them is represented by a flattened modified stem - the bottom, on which scales grow (modified leaves). Outside, scales are usually leathery and dry, and inside are fleshy and juicy. They store water, sugar and other valuable substances. In the axils of the scales on the bottom are the kidneys. When planted in the ground from the bulbs grows fibrous root system, and kidneys are developing from the kidneys - young onions.
Section 10. Shoot Modifications
1. What modifications of the roots do you know? What functions do they perform?
The main functions of the root are to fix the plant in the soil, suction the solutions of mineral compounds from the soil and transport them to the aerial parts thereof. However, the root can perform some additional functions. At the same time he acquires certain features of the structure, called modifications of the root.
In many plants (for example, beets, carrots), spare nutrients are deposited in the main root and base of the shoot. As a result, the main root thickens and turns into a root vegetable.
In other plant species (for example, in dahlias, spring scrubber, sweet potatoes), spare nutrients are deposited in additional or lateral roots, which take on a tuber-like shape. Such modifications are called root tubers.
In some plants growing in swamps and waterlogged soils, respiratory roots are formed. These are lateral roots growing up and rising above the surface of the soil (or water). In overmoistened soils, due to the low oxygen content, the respiration of the underground part of the plant is complicated. Therefore, these modified roots absorb oxygen directly from humid air.
There are roots and trailers. These are short additional roots that grow along the aerial part of the stem. With their help, climbing plant stems cling to the support. Remember the ivy that can attach even to the smooth vertical walls of houses.
There are also support roots that perform the function of supports.
A special type of root modification is observed in orchids. Some species of these plants are able to settle on the trunks of tropical rainforest trees. Their air roots hang freely and allow water to be obtained from moist air.
2. What leaf modifications do you know? What is their function?
Leaf modifications are irreversible changes in the shape of leaves developed during evolution as a result of the adaptation of plant organs to environmental conditions (i.e., the leaves perform new functions).
1. Spines - one of the most common variations; they serve as protection against eating by animals (cacti, threshers, barberries, acacia, camel thorn).
2. Antennae (in the complex leaves of some plant species) cling to the support, bringing the whole shoot to the light (peas, vetch).
3. Juicy scales of bulbs (onions, garlic), aloe leaves, cabbage head carry out the accumulating function.
4. Covering scales of buds protect delicate budding leaves and a growing cone from adverse environmental conditions.
5. Trapping devices ensure the life of insectivorous plants in swamps in conditions of a lack of nitrogen and other elements of mineral nutrition. The leaves of such plants have changed beyond recognition, becoming traps (Venus flytrap), jugs (nepentes). The leaves of some plants for their brilliant, brightly colored droplets on the hairs attract ants, flies, mosquitoes, other small insects; the juice produced during this process contains digestive enzymes (sundew).
3. What are the main functions of the stem?
Stems perform two main functions:
Stems endure leaves to light (supporting function);
The stalk transports substances between the leaves and the roots.
4. What is called escape?
A stem with leaves and buds located on it is called an escape.
Laboratory work
1. Consider the potato tuber. Find the base and the top.
2. View the eyes. What is their location on the tuber? Consider the buds in the eye, using a magnifying glass.
On the surface of the tuber in the grooves is 2-3 buds, called the eyes. Eyes more on the side of the tuber, which is called the tip. The opposite side - the base - the tuber is connected to the stolon.
3. Make a thin cross section of the tuber. Examine it to the light. Compare the cross section of the tuber with the cross section of the stem (Fig. 42).
4. Draw a cross section of the tuber.
See the answer to question number 3.
5. Put on the cut tuber iodine. Explain what happened.
If you drop iodine on a tuber cut, it will turn blue-violet, because starch when interacting with iodine gives the reaction. Potatoes contain starch in large quantities (this is the main storage substance of potato tubers).
6. Prove that a tuber is a modified underground shoot.
The cross section of the tuber is similar in structure to the cross section of the stem. When considering you can highlight cork, bast, wood and pith.
Laboratory work
Consider the external structure of the bulb. What is the significance of dry scales?
Outer scales are dry and leathery - perform a protective function.
2. Cut the onion along. Draw a longitudinal section of the bulb, mark the scales, bottom, buds, adventitious roots.
3. Prove that the bulb is a modified underground shoot.
Like the ground shoots, there are apical and axillary buds and leaves on the stem.
1. What modified underground shoots do you know? Name the plants with rhizome, tuber, bulb.
Modified underground shoots - rhizomes, tubers and bulbs.
The rhizome is in many plants, such as nettle, couch grass, iris, lily of the valley, indoor plants aspidistra.
Tubers are found, for example, in potatoes, crested hen, fodder plant Jerusalem artichoke (earth pear).
Bulbs form perennial plants - onion, lily, tulip, narcissus, wild goose onion.
2. How does potato tuber develop?
Underground shoots, which develop tubers, grow from the bases of above-ground stems. These shoots are called stolons. Tubers are apical thickenings of stolons.
Like the ground runaway, there are apical and axillary buds, of which young above-ground shoots develop in spring.
The cross section of the tuber is similar in structure to the cross section of the stem. When considering you can highlight cork, bast, wood and pith.
4. What is the structure of the bulb?
At the bottom of the onion bulb is located almost flat stem - bottom. On the bottom there are modified leaves - scales. The outer scales are dry and leathery, and the inner ones are fleshy and juicy. At the bottom there are buds located in the axils of the scales.
5. How to prove that the rhizome and bulb are modified shoots?
Like the ground shoots on the rhizome and bulb, there are apical and axillary buds, as well as modified leaves (foamed scales on the rhizome, succulent and dry scales on the bulb). Additional roots grow from the rhizome and the bottom (stem in the bulb), and young above-ground shoots develop from the apical or axillary buds in the spring.
6. What are the aboveground modifications of the escape you know?
Above-ground modifications of the shoot are spines of wild apple, pear, hawthorn, protecting plants from being eaten by animals. The antennae of grapes, cucumber, pumpkin, melon, strawberry mustache are also modified shoots. Another example of an elevated, modified shoot is the thickening of the internodes in the stem of the kohlrabi cabbage.
On what grounds can you distinguish the tubers from the root, rhizome from the root?
Tuber and rhizome will have buds, as well as modified leaves.
1. Place the onion bulb in a jar with a narrow neck so that it does not fall, but only touched the bottom of the water poured into the jar. Watch the development of the bulb of adventitious roots and green leaves. Why does it grow, although it is not in the soil?
An onion is a collection of beneficial substances needed for leaves and roots. In the presence of heat and moisture, growth begins. That is, the onion and without soil provides the plant with everything necessary.
2. With the onset of warm spring weather, observe the flowering of bulbous and rhizomatous plants. Identify the names of these plants. Mark the beginning and end of flowering, and also indicate what is characteristic of these plants in a given period of the year.
1. Simple early tulips bloom in early May for 15–30 days. A generation change of bulbs, unlike narcissus, occurs annually. During the short spring vegetation, the tulip blooms, bears fruit and lays the young bulbs under the ground, and the faded bulb dies.
2. Bloom daffodils in April and May. The narcissus has a perennial bulb. After the end of flowering, the leaves of the faded narcissus are not cut, but are waiting for them to wither. During this period, the nutrients are stored in the bulbs.
1. Lilies of the valley bloom from mid to late May. After the end of the flowering period, the fruits of the lily of the valley appear - small red berries.
2. Irises bloom profusely from late May to mid-July. In the summer, irises have a flower bud laid, so that irises winter with already formed buds, from which new flowers will appear in the new season.
why is potato a modified shoot?
Igor Kulikov
Or rather, the potato tuber is a modified shoot. The tuber has all the features inherent in the usual shoot - is a thickened and shortened stem of a herbaceous plant, has buds. The structure of the tissues is true modified in connection with the functions performed. But there are highlighted integumentary tissues, conductive beams, mechanical and storage tissues. And the parenchyma is most developed. In stolons (this is also an escape), on the contrary, conductive beams and mechanical tissues are most developed.
why the potato tuber is a modified underground shoot. really need help please.
Kitten Woof!
The potato tuber is a modified shoot, because on the tuber there are apical and lateral buds (as on a regular shoot) - eyes. The tuber area between the buds (eyes) is an internode. At the base of each kidney is a border - the place of attachment of the reduced leaf. As in normal shoots, the buds on the tubers are arranged spirally. Above-ground leafy and flowering shoots develop from the eyes of the tuber. Consequently, in addition to the storage function, the tubers perform the function of vegetative propagation.
Jimmy kane
has all the structures of the shoot: stem, leaf, kidney
how to prove that the tuber is a modified underground shoot?
Zinaida Zhenchevskaya
The potato tuber is a modified shoot because
on the tuber there are apical and lateral buds (as well as on an ordinary shoot) - eyes.
The tuber area between the buds (eyes) is an internode.
At the base of each kidney is a border - the place of attachment of the reduced leaf.
As in normal shoots, the buds on the tubers are arranged spirally. Above-ground leafy and flowering shoots develop from the eyes of the tuber.
Consequently, in addition to the storage function, the tubers perform the function of vegetative propagation.
Scots Hammer
Like the stem, the tuber has a storage function.
It has buds, and in the cross section it does not show the same zones as on the shoot.
Prove that potato tuber is a modified underground shoot?
Peculiar underground storerooms have perennial herbaceous plants. The aboveground parts of these plants die off every autumn. In the soil there are roots and modified underground shoots. They do not look like ordinary above ground. It is in these modified shoots that the reserves of organic substances are deposited for the winter. Modified shoots are rhizomes, tubers and bulbs.
If you dig up the rhizome of any plant from the ground, you can see that it looks like a root. But the rhizome, as in above-ground shoots, has apical and axillary buds, as well as membranous scales - modified leaves. Additional roots grow from the rhizome.
In the spring, young above-ground shoots develop from the apical or axillary buds of the rhizome. They use the nutrients deposited in the rhizome in the fall. If a piece of rhizome with a bud and adventitious roots is planted in the soil, a new, independently living plant will develop.
Tubers are characteristic of few plants. Underground shoots, on the tops of which tubers develop, grow from the bases of the above-ground stems; these shoots are called stolons. Tubers are apical thickenings of stolons.
Tuber has short internodes; it does not contain chlorophyll, but when exposed to light it may turn green. Consider the potato tuber. On its surface in the grooves of 2-3 located kidneys, or eyes. Eyes more on the part of the tuber, which is called the tip. The opposite side - the base - the tuber is connected to the stolon. The structure of the tuber convinces that the tuber is a modified underground shoot.
From the leaves of the potato through the stems in the stolons constantly flowing organic matter and in the form of starch are deposited in the tops. The tops of stolons grow, thicken, and by the autumn turn into large tubers.
sergey Mmmm
why the potato tuber and onion bulb are modified shoots
Because they are educated from the underground part of the shoot, and the shoots are called the part of the plant that has interlining and knots, and in most cases the water does not suck.
How to prove that potato tuber is an escape ??
Elena Kazakova
1) it has eyes (buds). including apical poska
2) the internal structure of the tuber is similar to the structure of the stem
Conclusion: a tuber is a modified underground shoot, which serves to store nutrients (starch)
Andrey Ivanov
Galya Sineokaya
escape from what or from what?
Potato tubers are interesting formations. In the section, they have a structure the same as the stem-bark, phloem, wood, core. the core (the central region of the stem tissue) constitutes a significant part of the tuber.
The shoots on the tuber, as well as the shoots on the stem, are arranged in one or two spirals. Between the kidney eyes are internodes. There is a apical bud from which the main shoot develops.
Thus, the external and internal structure of the tuber indicates that this is a modified underground shoot.
1. The root absorbs minerals and water from the earth. Does it make potatoes?
2. From the potatoes grow buds, like a shoot.
3. As in the shoot, nutrients are stored in the potato.
