Class Monocots

Systematic features of monocots:

The presence of one cotyledon in the embryo

root system fibrous

The leaves are mostly simple, entire, with parallel or arcuate venation.

Three-membered flowers

Liliaceae family - 2,800 species.

Lily - perennial, herbaceous, bulbous or rhizomatous plants.

The flowers are regular, bisexual, solitary or collected in an inflorescence brush, spike, umbrella, panicle

Perianth simple, consists of six free (tulip) or fused (lily of the valley) leaves. There are usually six stamens, three in a circle, one pistil with a solid or three-lobed stigma.

The fruit is a capsule or berry. When ripe, the boxes crack-vayutsya on the sash.

Economic value:

Food: onion, garlic, leek, asparagus, etc.

Decorative: lily, tulip, hyacinth, asparagus, etc.

Medicinal: May lily of the valley, kupena officinalis, aloe tree, hellebore.

Family Cereals (Poat grasses) - 12,000 species

Among the grasses there are many annuals, but perennial rhizomatous plants predominate. The stalk of almost all cereals - solo mine Articular at the nodes and hollow at the internodes. Corn and sugar cane have pith in their stems.

The leaves are alternate, with a leaf sheath, with parallel venation. Leaf sheaths serve as protection for internodes, which retain the ability to intercalate growth for quite a long time. Branching of the stems of cereals occurs near the base, in the so-called tillering zone, consisting of closely spaced nodes. In the axils of the leaves extending from these nodes, buds are laid, giving rise to lateral shoots. Depending on the direction of growth, a turf, a loose bush or a long rhizome with single above-ground shoots is formed.

Grasses are wind-pollinated plants, so the flower has a number of adaptations for wind-pollination.

Perianth simple, inconspicuous, stamens with flexible long filaments and swaying anthers attached to it with their middle, light dry pollen and feathery stigmas. Some grasses self-pollinate. The flower usually has one pistil, three stamens, two floral membranes and two lemmas. O (2) +2 T 3 P 1

Simple inflorescences - spikelets - are collected in complex inflorescences of the type

Complex ear (rye, wheat, barley),

Cob (corn)

Panicle (oats),

Sultan or false ear (timo-feevka)

The fruit of cereals grain. The largest part of the grain is the endosperm, which contains starch, as well as proteins, fats, vitamins, which determines the great practical importance of cereals.

Economic value:

Bread, technical: wheat, rye, barley, oats, corn, rice, sorghum, sugar cane

Stern: fescue, bluegrass, timothy, hedgehog.

Construction: bamboo, reed.

Weeds: couch grass, wild oat, bristle, barnyard.

Families of the Angiosperm department

How are dicotyledonous plants different from monocotyledonous plants? Give at least 4 signs. 1) dicots have two cotyledons in the seed embryo, monocots have one; 2) the root system of dicots, as a rule, is pivotal, and that of monocots is fibrous; 3) in dicots, the leaves are simple and complex, the venation is reticulate, in monocots the leaves are always simple, the venation is parallel and arcuate; 4) as a rule, in dicots, flowers with a double perianth, four- or five-membered, in monocots - flowers with a simple perianth, three-membered.

On what grounds are plants of the families Liliaceae and Cereals classified as Monocotyledonous? Specify at least 4 signs. 1) seed with one cotyledon; 2) fibrous root system; 3) simple leaves with parallel or arcuate venation; 4) a three-membered flower with a simple perianth.

Identify the family from the picture. flowering plant. Name the type of inflorescence depicted. What fruit is typical for this family? 1) family Bluegrass (Grass); 2) complex inflorescence - complex spike; 3) fruit - grain.

Determine the class and family of the angiosperm shown in the figure. Name the types of inflorescences and fruits characteristic of this family. . 1) class Monocot plants, Liliaceae family; 2) single flowers or inflorescence - brush; 3) fruit - a berry or a box.

It is known that in practice Agriculture before sowing seeds, check their germination. Explain how and why they do it

1) to determine the germination of seeds, a certain number of them (100) are placed in optimal conditions for germination and the percentage of germinated seeds is calculated;

2) germination is determined to establish the quality of the seed, on which the yield of the plant depends

Many representatives of the Rosaceae family have a fruit - a drupe. What structural features of the fruit ensure the dispersal of the seeds of these plants? 1) the drupe has juicy pulp, which attracts animals; 2) the fruits are eaten by birds or mammals, while the seeds are not digested in the digestive canal of the animal and are removed with droppings to the outside, which contributes to their spread.

Read the information .

Class monocot plants Plants in which the seed embryo contains one cotyledon.

General signs, inherent in all angiosperms, including monocots:

• reproduction with the formation of seeds

• always internal fertilization- double

• life phases always successively replace each other (the sporophyte always prevails, and the gametophyte undergoes a strong reduction and develops inside the spore)

• all seed plants are heterosporous

• in the process of reproduction there is a stage - pollination

The class of monocotyledonous plants consists of approximately 65 families.

Consider large families monocot plants.

Consider the morphological structure of the species sowing rye .

Adaptation- ability to adapt to environmental conditions.

Examples of adaptation rye :

1. Rye has a fibrous root system that penetrates to a depth of 2 m. This allows it to grow even on sandy soils and quickly absorb nutrients from the soil.

2. The leaf blade of rye is covered with hairs on the upper side, which indicates a comparative resistance to lack of moisture and adaptability to light sandy soils.

scientific classification

Kingdom - plants

Department - Angiosperms

Class - Monocots

Order - Cereals

Family - Cereals (cereals) or Bluegrass

Genus - Rye

View - sowing rye

Consider comparative characteristic classes .

Used Books:

1. Biology: a complete guide to preparing for the exam. / G.I. Lerner. - M.: AST: Astrel; Vladimir; VKT, 2009

2. Biology: Plants, bacteria, fungi, lichens: textbook. for 6-7 cells. general education Institutions / T.I.Serebryakova, A.G.Elenevsky, M.A. Gulenkova and others - 5th ed. - M.: Enlightenment, 1999.

3. Biology for applicants to universities. Intensive course / G.L. Bilich, V.A. Kryzhanovsky. - M.: Onyx Publishing House, 2006.

4. Biology: study guide / A.G. Lebedev. M.: AST: Astrel. 2009.

5. Biology. Full course of general education high school: tutorial for schoolchildren and entrants / M.A.Valovaya, N.A.Sokolova, A.A. Kamensky. - M.: Exam, 2002.

Floras are usually divided into monocotyledonous and dicotyledonous plants, which differ mainly in the structure of the embryo. Nevertheless, these classes of plants also have other differences in the structure of the vegetative and generative organs.

Class Dicotyledons, or Magnoliopsids: the structure of plants and their brief characteristics

To date, this class is considered quite large, as it includes about 200 thousand species. Its representatives have a number of very characteristic distinguishing features.

Dicot plants are represented different forms- these are trees, and bushes, and herbs. Woody species inside the stem have a rather powerful layer of cambium - a special tissue that ensures its growth in width. The leaves of plants can be both simple and complex, but in almost all species they are cuttings - sessile leaf blades are not typical for this class. The venation of the plate is in most cases reticulate. predominantly pivotal - has a main, main root, from which lateral, small sizes.

Another feature is the structure. Most species have large flowers with bright coloration. They have a double perianth (sepals and petals), flowers are predominantly five- or four-membered. Dicotyledonous plants are most commonly pollinated by insects.

And, of course, the structure of the embryo, which has two lateral cotyledons, is very characteristic. By the way, the name of the class is connected with this feature.

Dicot plants: the most common species

This class includes great amount species that are included in several thousand genera and three hundred families. The most famous of them are the following.

Cruciferous family - its representatives are distributed mainly in the planets. Most of its species are herbaceous forms or small shrubs. Everyone knows such representatives of cruciferous plants as cabbage, radish, horseradish, turnip, mustard and radish.

The Rose family includes trees, shrubs, and which are mainly distributed in temperate or subtropical climates. For example, the well-known wild rose and decorative roses belong to this group. This also includes a large part including apple, pear, cherry, mountain ash, raspberry, bird cherry, blackberry.

The legume family - its woody forms and shrubs are distributed mainly in tropical and subtropical countries, while herbaceous ones prefer a more temperate and even cold climate. All representatives of the group are characterized by a specific corolla of the "butterfly" type. This group includes the following well-known plants: peas, beans, alfalfa, beans, soybeans. By the way, some species are actively involved in the nitrogen cycle.

Class a brief description of

This group is represented mainly by herbaceous plants - trees and shrubs are extremely rare in it. Their stems generally do not contain cambium and are therefore not capable of growing in thickness. The leaves are simple, with solid edges. They do not have a petiole and are attached to the stem by the edge of the leaf blade, which is why they are called sessile leaves. Venation in most cases parallel or arcuate.

Another feature is the fibrous root system, which does not have a main root. In the embryo there is only one cotyledon, as evidenced by the name of the class.

Most of Monocot plants are pollinated by the wind. Therefore, their flowers are small, dim, with a single perianth, mostly three-membered.

Typical representatives of this group are cereals: wheat, oats, corn, rice and others.

In which the seed embryo has two lateral cotyledons. Dicotyledons are an ancient large group of plants, many of whose representatives have great importance In human life. Among them there are food and fodder crops - potatoes, beets, buckwheat, oilseeds - sunflower, fruit and berry crops - grapes, as well as medicinal, spicy, fibrous plants and many others.

In addition to two symmetrical cotyledons, Magnoliopsids also have other characteristic features. Most often among them there are plants with a root system, in which the main root is clearly expressed and there are practically no lateral and adnexal ones. In the stems of representatives of this class of Angiosperms there is a cambium, thanks to which the plants can increase in thickness. The leaves of Dicotyledons can be both simple and complex, with jagged edges and cuttings. Magnoliopsid flowers, four- or five-membered, most often have a double perianth. Among the Dicotyledons, it is distributed by insects.

monocots

Scientists are inclined to believe that Monocots, or Lileopsids, are a younger class of plants descended from Dicotyledons. This class is less numerous than the previous one, but also has many representatives. Monocots include Lily, Asparagus, Orchid, Sedge, Palm, Cereals. The main difference between this class is that the Lileopsid seed embryo has only one cotyledon.

There are other features of this group that are easier to see with the naked eye. The root system of most monocots. The main root quickly ceases to develop, but numerous adnexal and lateral roots. As a rule, Lileopsid stems lack cambium, so they are thin and unable to grow in thickness. While herbaceous plants and trees are found among the Dicotyledons, representatives of the Lileopsida class are herbaceous plants and very few trees. The leaves of these plants are simple, without. As a rule, they are long, as they grow for some time due to the educational tissue located at their base. Monocots most often have three-membered flowers with a simple perianth, because few representatives of this class have to attract insects for. Usually monocot pollen resort to the help of the wind.

Characteristics of the Buttercup family

The Department. Magnoliophyta - angiosperms

Class. Magnoliopsida - dicots

Subclass. Ranunculidae - ranunculids

Order. Ranunculales - buttercups

Family. Ranunculaceae - ranunculaceae

Kinds :

Trollius europeus - European bathing suit

Pulsatilla patens - open lumbago

Anemone silvestris – forest anemone

Delphinium elatum - high larkspur

Aconite napellus - real aconite

Adonis vernalis – spring adonis

Ranunculus acris – pungent ranunculus

Life Form: annual and perennial herbaceous plants, rarely shrubs.

Root system: fibrous, some species have rhizomes and tubers.

Leaves: simple, without stipules, palmately or pinnate or separate, some species form a rosette of basal leaves.

Leaf arrangement: next.

Inflorescences: cymoid in the form of monochasia and botryoid racemes and panicles.

flowers: actinomorphic, rarely zygomorphic, acyclic or hemicyclic, with simple or double perianth, androecium always consists of an indefinite number of free stamens, gynoecium apocarpous, consists of a large number of carpels, rarely 5, 3, 1. Ovary top.

flower formulas:

European bathing suit *P ∞ A ∞ G ∞

lumbago open * R 6 A ∞ G ∞

forest anemone * R 5 A ∞ G ∞

larkspur high  Ca 5 Co 3+2 A ∞ G 3

real aconite  Ca 5 Co 6+2 A ∞ G 3-7

spring adonis * Ca 5 Co ∞ A ∞ G ∞

ranunculus caustic * Ca 5 Co 5 A ∞ G ∞

Fetus: apocarp: multi-leaf or multi-nutlet.

BAS: cardiac glycosides, alkaloids, flavonoids, etc.

Distribution and habitat: in temperate regions of the northern hemisphere, mainly in meadows and forests.

Peculiarities: lot poisonous plants. It is possible to trace the evolution of ranunculus flowers, which went in the direction of adaptation to pollination by various pollinators: from acyclic flowers with a simple perianth and an indefinite number of flower parts to hemicyclic flowers with a double perianth and a strictly defined number of perianth parts.