Why is broadleaf forest considered more. Why is a broadleaf forest considered a more resilient ecosystem?

PRACTICAL WORK

evolution.

1. Find errors in the given text. Indicate the numbers of the sentences in which they are made, correct them.

1. Find errors in the given text. Indicate the numbers of the sentences in which they are made, correct them.

1. Find errors in the given text. Indicate the numbers of the sentences in which they are made, correct them.

1. Using the picture, determine what form of selection it illustrates and justify it. Will the size of the ears of hares change during the process of evolution under the influence of this form of natural selection and under what living conditions will this selection manifest itself?

Number of individuals

Significance value

PRACTICAL WORK

SOLVING ENVIRONMENTAL PROBLEMS 11 CL

1. What types of environmental factors contribute to the regulation of wolf numbers in an ecosystem? Explain your answer.

1. Explain why not all the energy supplied by food is spent on the growth of the animal. Give at least three reasons.

1. Brook trout lives in water with an oxygen concentration of at least 2 mg/l. When its content drops to 1.6-2 mg/l or less, the trout dies. Explain the reason for the death of trout, using knowledge about the reaction norm of the trait.

1. What characterizes the geographic mode of speciation? Please provide at least three items.

1. How is the population of insects, insectivores and insects regulated? birds of prey in a mixed forest ecosystem, if the number of insects increases?

1. Blood-sucking insects are common inhabitants of many biocenoses. Explain in what cases they occupy the position of consumers of II, III and even orders in food chains.

1. Find errors in the given text. Indicate the numbers of the sentences in which they are made, correct them.

1. A type criterion is a set of characteristics that distinguish this type from another. 2. The basis of the physiological criterion is a combination of factors external environment, in which the species exists. 3. The genetic criterion is characterized by a certain karyotype. 4. Ecological criterion is a certain area occupied by a species in nature. 5. Other criteria for a species include: morphological, biochemical, geographical, etc. 6. To establish species identity, it is enough to use one criterion.

1. In the forest biogeocenosis, trees were treated with pesticides to kill mosquitoes and midges. Specify at least four consequences the impact of this event on the forest biogeocenosis.

1. Find errors in the given text. Indicate the numbers of the sentences in which they are made, correct them.

1. Charles Darwin identified the driving forces of evolution organic world.

2. He included the diversity of species, the struggle for existence and natural
nal selection. 3. Charles Darwin believed that the material for evolution is not
hereditary variability. 4. He also called it a modification of
changeability. 5. Natural selection, according to Darwin, plays a creative role
role. 6. He considered natural selection as the main driving force)
evolution.

1. Treatment with antibiotics of human diseases caused by microorganisms becomes ineffective over time. It is necessary to search for new drugs. In terms of the evolutionary process, explain how antibiotic resistance develops.

1. Rodents are the largest order of mammals in terms of the number of species in their distribution. What makes rodents thrive in nature? Give at least three reasons.

1. Why a decline in the number of a species can cause its extinction. Give at least three reasons. Explain your answer

1. Find errors in the given text. Indicate the numbers of the sentences in which they are made, correct them.

1. Visible rays account for most of the energy of solar radiation reaching earth's surface. 2. Life on Earth is possible only because long-wave rays are blocked by the ozone screen. 3. In small doses, infrared rays prevent the occurrence of rickets in humans. 4. Infrared rays are an important source of internal energy. 5. The influence of three areas of solar radiation on organisms is classified as biotic environmental factors of influence.

1. Why is a broadleaf forest considered a more resilient ecosystem than a forb meadow? Provide at least three pieces of evidence.

1. The rate of photosynthesis depends on factors, including light, carbon dioxide concentration, water, and temperature. Why are these factors limiting the photosynthesis reaction?

1. Explain why the reduction in the number of wolves due to shooting in tundra biocenoses leads to a decrease in the supply of moss - food for reindeer.

1. In nature, the oxygen cycle occurs. What role do living organisms play in this process?

1. Carp were released into an artificial reservoir. Explain how this can affect the number of insect larvae, crucian carp and pike living in it.

1. Why is a mixed forest ecosystem considered a more sustainable ecosystem than a spruce forest ecosystem?

1. In a small reservoir formed after a river flood, the following organisms were found: slipper ciliates, daphnia, white planaria, big pond snail, Cyclops, Hydra. Explain. Can this body of water be considered an ecosystem? Provide at least three pieces of evidence.

1. What environmental factors contribute to the regulation of the number of wolves in the ecosystem?

1. How does a natural ecosystem differ from an agroecosystem?

1. What is the role of bacteria in the cycle of substances?

1. Squirrels, as a rule, live in coniferous forests and feed mainly on spruce seeds. What biotic factors can lead to a decline in the squirrel population?

1. Clover grows in meadows and is pollinated by bumblebees. What biotic factors can lead to a decline in clover populations?

1. What changes in biotic factors can lead to an increase in the population of a naked slug that lives in a forest and feeds mainly on plants?

1. Find errors in the given text. Indicate the numbers of the sentences in which they are made, correct them.

1. A population is a collection of freely interbreeding individuals different types, long time inhabiting a common territory.2. The main group characteristics of a population are size, density, age, sex and spatial structure. 3. The totality of all genes in a population is called the gene pool. 4. The population is structural unit wildlife. 5. The population size is always stable.

1. Why are plants (producers) considered the initial link in the cycle of substances and energy conversion in the ecosystem?

1. As a result of volcanic activity, an island was formed in the ocean. Describe the sequences of ecosystem formation on a newly formed landmass. Please provide at least three items.

1. As a result of a forest fire, part of the spruce forest burned out. Explain how its self-healing will occur. Specify at least three stages.

1. In some forest biocenoses, to protect chicken birds, mass shooting of daytime birds of prey was carried out. Explain how this event affected the number of chickens.

1. The color of the white hare's coat changes throughout the year: in winter the hare is white, and in summer it is gray. Explain what type of variability is observed in the animal and what determines the manifestation of this trait.

1. How does the land-air environment differ from the water environment?

1. Find errors in the given text. Indicate the numbers of the sentences in which they are made, correct them.

1. Explain how plants are harmed acid rain. Give at least three reasons.

1. What are the manifestations of morphological, physiological and behavioral adaptations to environmental temperature in warm-blooded animals?

1. What role do birds play in the forest biocenosis? Provide at least three parameters.

1. Using the picture, determine what form of selection it illustrates. Justify your answer. Will the size of the ears of hares change during the process of evolution under the influence of this form of natural selection and under what living conditions will this selection manifest itself?

Number of individuals

Significance value

1. Birds and mammals have achieved great success in evolution in mastering? terrestrial-air environment compared to other vertebrates. Explain what common features of their organization contributed to this. Give less than three signs.

1. Find errors in the given text. Indicate the numbers of the sentences in which they are made, correct them.

1. A population is a collection of freely interbreeding individuals of the same species that inhabit a common territory for a long time. 2. Different populations of the same species are relatively isolated from each other, and their individuals do not interbreed. 3. The gene pool in populations of the same species is the same. 4. The population is the elementary unit of evolution. 5. A group of frogs of the same species living in the deep during one summer constitutes a population.

1. What characteristics do plants living in arid zones have?

1. The body shape of the callima butterfly resembles a leaf. How was this butterfly body shape formed?

Help please. Biology. and got the best answer

Answer from Daria Gubina[newbie]
1. Birds that eat insects nest in hollow trees. If they are cut down, insect pests will damage young trees and plants, which will lead to the gradual death of the forest.
2. Herbaceous, light-loving plants develop first, then sprouts of birch, aspen, and pine appear, the seeds of which fell with the help of wind, birds, insects, and a small-leaved or pine forest is formed; under the canopy of light-loving species, shade-tolerant spruce trees develop, which will subsequently completely displace other trees.
3. Grass emits less oxygen per m^2 of land than a tree! The grass is covered with snow in winter, but the tree still continues to fulfill its mission of releasing oxygen.
5The food network is formed from a variety of interconnected food chains, which means that its diversity is based on the diversity of species, the presence among them of producers, consumers, decomposers and the variety of their food (broad food specialization).

Exercise 1.

Consider the proposed scheme. Write down the missing term in your answer, indicated by a question mark in the diagram.

Explanation: Reproduction of organisms can be sexual or asexual (without the participation of germ cells).

The correct answer is asexual.

Task 2.

Choose two correct answers out of five and write down the numbers under which they are indicated.

The hybridological research method is used

1. Embryologists

2. Breeders

3. Genetics

4. Environmentalists

5. Biochemists

Explanation: hybridological method - a method for producing hybrids. They are used in genetics to determine the characteristics and inheritance of a trait and in breeding to develop new breeds, varieties, strains.

The correct answer is 23.

Task 3.

An mRNA molecule, a fragment of which contains 96 nucleotide residues, takes part in protein synthesis. Determine the number of nucleotide residues in a section of the DNA template strand that carry information about the primary structure of the protein.

Explanation: during transcription (copying a section of DNA - a gene - into mRNA) DNA and mRNA end up with the same number of nucleotides, since the gene encodes a protein and the mRNA must convey this encoded information unchanged.

In this task, non-coding regions of DNA are neglected - introns, which are cut out of DNA, so that mRNA is smaller than DNA.

The correct answer is 96.

Task 4.

The characteristics listed below, except two, are used to describe the structure, functions, and organoid of the cell depicted. Identify two characteristics that “drop out” from the general list and write down the numbers under which they are indicated in the table.

1. Packages and carries synthesized substances out of the cell

2. Participates in the formation of lysosomes

3. Provides oxidative phosphorylation

4. Consists of one membrane

5. Contains interconnected grains

Explanation: The figure shows the Golgi apparatus. It packages and removes synthesized substances from the cell (for example, proteins from ribosomes enter the Golgi apparatus and then are distributed throughout the cell), participate in the formation of lysosomes, and are single-membrane. They do not carry out oxidative phosphorylation (like mitochondria) and do not contain grana (like chloroplasts).

The correct answer is 35.

Task 5.

Establish a correspondence between the characteristics and phases of photosynthesis.

Characteristics

A. Photolysis of water

B. Carbon dioxide fixation

B. Splitting of ATP molecules

D. Excitation of chlorophyll by light quanta

D. Glucose synthesis

Phases of photosynthesis

1. Light

2. Dark

Explanation: The light phase of photosynthesis requires light. It includes: photolysis of water, splitting of ATP molecules, excitation of chlorophyll by light quanta. All processes take place on the membrane. The dark phase of photosynthesis does not require light. It includes the Calvin cycle, during which CO2 fixation and glucose synthesis occur.

Correct answer: 12112.

Task 6.

Determine the ratio of females and males in the offspring formed by crossing two heterozygotes. Write your answer as a sequence of numbers showing the ratio of phenotypes in descending order.

Explanation: the question is posed incorrectly, since the offspring does not depend on the genotype. The ratio of females to males will always be 50:50 (i.e. 1:1).

The correct answer is 11.

Task 7.

The following characteristics, except two, are used to describe the causes of combinational variability.

1. Chance meeting of gametes during fertilization

2. Chromosome spiralization

3. DNA replication in interphase

4. Recombination of genes during crossing over

5. Independent chromosome segregation in meiosis

Explanation: combinative variability is determined by: a random meeting of tentative gametes during (various combinations of) fertilization, recombination of genes during crossing over or independent divergence of chromosomes in meiosis. Chromosome spiralization and DNA replication in interphase are not characteristics of combinative variability.

The correct answer is 23.

Task 8.

Establish a correspondence between the characteristics and stages of formation of lancelet embryos.

Characteristics

A. Invagination of a group of cells into the blastula

B. Mitosis of the zygote

B. Formation of the walls of the primary intestine

D. Formation of blastocoel

D. Formation of blastomeres

Embryogenesis stages

1. Single-layer embryo

2. Double-layered embryo

Explanation: The blastula is a single-layer stage, which means everything that is included in it belongs to the single-layer period of embryo development (mitosis of the zygote, formation of blastomeres, formation of the blastocoel). During gastrulation, invagination occurs and the invaginating cells represent the second layer, that is, the characteristics of a two-layer embryo include: Invagination of a group of cells into the blastula and the formation of the walls of the primary intestine.

The correct answer is 21211.

Task 9.

1. They are perennial plants

2. Contain chloroplasts with chlorophyll

3. Have flowers and inflorescences

4. Form fruits with seeds

5. Represented by a variety of life forms

6. Reproduce by seeds

Explanation: Angiosperms are the most progressive group of plants. They differ from all others by the presence of a flower and a fruit. Also, unlike gymnosperms, they are represented by a variety of life forms: grasses, shrubs, trees (gymnosperms are only woody forms). General characteristics: perennial plants, the presence of chloroplasts with chlorophyll, reproduction by seeds.

The correct answer is 126.

Task 10.

Establish a correspondence between animals and body temperature characteristics.

Animals

A. House Sparrow

B. Agile lizard

B. Common dolphin

G. Nile crocodile

D. Common newt

E. Common mole

Features of body temperature

1. Constant

2. Fickle

Explanation: birds (house sparrow) and mammals (common dolphin, common mole) have a constant body temperature (they are warm-blooded). Amphibians (common newt) and reptiles (snap lizard, Nile crocodile) have an unstable body temperature (they are cold-blooded).

Correct answer: 121221.

Task 11.

Establish the sequence of arrangement of systematic groups of plants, starting with the smallest taxon. Write down the corresponding sequence of numbers in the table.

1. Common radish

2. Angiosperms

3. Cruciferous

4. Dicotyledons

5. Radish

6. Eukaryotes

Explanation: We arrange systematic groups, starting with the smallest.

Type Common radish

Rod Radish

Family Cruciferae

Class Dicotyledons

Department Angiosperms

Overkingdom Eukaryotes

The correct answer is 153426.

Task 12.

Choose three correct answers out of six.

Leukocytes are blood cells that

1. Formed in red bone marrow

2. Able to change their shape

3. Contain kernels

4. Synthesize hemoglobin

5. They release substances to form a blood clot.

6. Ripen in nerve ganglia

Explanation: leukocytes are white blood cells, they are responsible for immunity, they can absorb foreign particles by changing the shape of the cell (phagocytosis), they have nuclei, and are formed in the red bone marrow. They do not synthesize hemoglobin, do not participate in the formation of a blood clot, and do not ripen in nerve ganglia.

The correct answer is 123.

Task 13.

Match characteristics and departments nervous system.

Characteristics

A. Coordinates the work internal organs

B. Regulates metabolic processes

B. Acts autonomously, regardless of a person’s wishes

D. Provides voluntary movements of the limbs

D. Regulates the activity of smooth muscles

E. Regulates contraction skeletal muscles

Divisions of the nervous system

1. Vegetative

2. Somatic

Explanation: the somatic nervous system controls muscle function. Autonomic (autonomous) nervous system - exercises control over the work of internal organs, that is, the autonomic nervous system coordinates the work of internal organs, metabolic processes, and smooth muscle activity. The somatic nervous system regulates voluntary movements of the limbs, that is, the contraction of skeletal muscles.

The correct answer is 111212.

Task 14.

Establish the sequence of arrangement of the structures of the eyeball, starting with the cornea. Write down the corresponding sequence of numbers in the table.

1. Retinal neurons

2. Vitreous body

3. Pupil in a pigment membrane

4. Light-sensitive rod and cone cells

5. Convex transparent part of the tunica albuginea

Explanation: Let's look at the structure of the eyeball.

The outermost structure is the convex transparent part of the membrane, then the pupil in the pigment membrane, then the vitreous body, then the neurons of the retina and, finally, the light-sensitive cells - rods and cones.

The correct answer is 53214.

Task 15.

Select three sentences from the text that describe the paths of macroevolution of the organic world. Write down the numbers under which they are indicated in the table.

Explanation: The paths of macroevolution of the organic world are described in sentences 1, 4 and 5.

Macroevolution is the process of formation of large systematic units. We pay attention to the phrases: “aromorphosis”, “general degeneration”, “increased level of organization”, “morphophysiological regression”.

The correct answer is 145.

Task 16.

Establish a correspondence between the characteristics and criteria of the Honey Bee species.

Characteristics

A. Social way of life

B. Difference in size between males and females

B. Development of larvae in honeycombs

D. Presence of hairs on the body

D. Feeding on nectar and pollen of flowers

E. Faceted eyes

Type criteria

1. Morphological

2. Ecological

Explanation: morphological criterion describes external structure organisms, that is, the difference in size of males and females, the presence of hairs on the body, compound eyes. Ecological criteria describe the interaction of a species with the environment and with other organisms: public image life, development of larvae in honeycombs.

The correct answer is 212121.

Task 17.

Choose three correct answers out of six.

In biogeocenosis, heterotrophs, unlike autotrophs,

1. They are producers

2. Provide a change in ecosystems

3. Increase the supply of molecular oxygen in the atmosphere

4. Extract organic matter from food

5. Convert organic residues into mineral compounds

6. Act as consumers or decomposers

Explanation: heterotrophs are living organisms that consume organic substances and convert them into mineral compounds. In the food chain, heterotrophs play the role of consumers or decomposers. Producers are autotrophs; green plants release oxygen during photosynthesis, increasing its supply in the atmosphere.

The correct answer is 456.

Task 18.

Match the characteristics and types of ecosystems.

Characteristics

A. Various circuits and power networks

B. Great variety of species

B. Presence of monocultures

D. Closed cycle of substances

D. Instability over time

E. Need for additional energy

Types of ecosystems

1. Agrobiocenosis

2. Biogeocenosis

Explanation: agrobiocenosis is an artificial community that is unstable, as it has a number of disadvantages: the presence of a monoculture, instability over time, and the need for additional energy.

Biogeocenosis is a natural community that is quite stable, since there are various food chains and networks, a wide variety of species, and a closed circulation of substances.

The correct answer is 221211.

Task 19.

Establish the sequence of formation of aromorphoses in animals in the process of evolution. Write down the corresponding sequence of numbers in the table.

1. The appearance of internal fertilization

2. The emergence of the sexual process

3. Formation of the chord

4. Formation of five-fingered limbs

Explanation: Among the listed signs, the earliest is the appearance of the sexual process (even in Coelenterates), then internal fertilization, the appearance of the notochord and the formation of five-fingered limbs.

The correct answer is 2134.

Task 20.

Look at the picture depicting cell division and determine its phases, the set of chromosomes in the daughter cells, and what specific cells are formed as a result of such division in plants.

Fill in the blank cells of the table using the terms in the list. For each lettered cell, select the appropriate term from the list provided.

List of terms

1. Prophase, metaphase, telophase

2. Somatic

3. Diploid

4. Prophase 2, metaphase 2, anaphase 2, telophase 2

5. Prophase 1, metaphase 1, anaphase 1, telophase 1

6. Haploid

7. Dispute

8. First meiotic division

Explanation: The figure shows the second division of meiosis, as haploid cells are formed. In plants, spores are formed during meiosis, and gametes are formed during mitosis (vice versa in animals).

The correct answer is A - phases of cell division - prophase 2, metaphase 2, anaphase 2, telophase 2

B - set of chromosomes in daughter cells - haploid

B - what specific cells are formed in plants - spores

The answer is 467.

Task 21.

Analyze the graph "Survival of Mouflon at London Zoo." Select statements that can be formulated based on the analysis of the data presented.

Statements:

1. A group of animals consisting of 79 individuals was studied

2. 3-4 individuals live up to approximately 9.5 years

3. Born individuals often die in the third year of life

4. Most individuals live up to eight years

5. In the original population average age individuals are one year old

Explanation: as can be seen from the graph, greatest number individuals are 1-4 years old (12-48 months). A total of 79 individuals were studied, but only 3-4 of them survive to 9.5 years (114 months).

The correct answer is 12.

Task 22.

They took several tendrils from one strawberry plant, rooted them and obtained adult plants, which were transplanted to another part of the plantation. However, the fruits of some daughter plants turned out to be smaller than those of the mother plant. Name the method used to propagate strawberries. Explain the reason for the appearance of small fruits.

Explanation: The assignment shows a vegetative method of propagation. The size of the fruit may vary within the normal reaction range depending on environmental conditions. This type of variability is called modification or phenotypic.

Task 23.

Which plant organs are indicated in the figure by numbers - 1, 2, 3? What is their role in plant life? What organ are they a modification of?

Explanation: 1 - tuber, 2 - bulb, 2 - rhizome. These organs are modified shoots. With the help of modified shoots, the plant can reproduce vegetatively.

Task 24.

Find errors in the given text. Indicate the numbers of the sentences in which errors were made and correct them.

1. The endocrine glands have ducts through which the secretion enters the blood. 2. These glands secrete biologically active regulatory substances - hormones. 3. All hormones are proteins by chemical nature. 4. Pancreatic hormone - insulin. 5. It regulates blood glucose levels. 6. With its deficiency, the concentration of glucose in the blood decreases.

Explanation: errors were made in sentences 1, 3, 6.

Sentence 1 - the endocrine glands secrete hormones into the blood and do not have ducts, the exocrine glands secrete secretions into the duct.

Proposition 3 - not all hormones are proteins (for example, adrenaline is not a protein).

Proposition 6 - insulin helps glucose enter the cells, so when there is a deficiency, the concentration of glucose in the blood does not decrease, but increases (this disease is called diabetes mellitus).

Task 25.

Class Mammals are a thriving group of vertebrates. Explain what aromorphoses allowed them to achieve biological progress. Specify at least four characteristics.

Explanation: aromorphoses of mammals:

1. Warm-blooded - independent of temperature environment (high level metabolism).

2. The appearance of wool - preservation of heat.

3. Differentiation of teeth - they can eat different foods.

4. Four-chambered heart - complete separation of venous and arterial blood.

5. Highly developed cerebral cortex (characteristically complex behavior).

6. Outer ear - sound is collected and passes into the auditory tube.

7. The ability to feed young with milk and care for offspring.

Task 26.

Why is a broadleaf forest considered a more resilient ecosystem than a forb meadow? Provide at least three pieces of evidence.

Explanation:

1. A forb meadow is represented by plants with only one life form - herbaceous plants, and in a broad-leaved forest there are grasses, shrubs, and trees (there are layers).

2. In a broad-leaved forest there are more branched chains.

3. Broadleaf forest has a greater diversity of species.

Task 27.

The chromosome set of somatic wheat cells is 28. Determine the chromosome set and the number of DNA molecules in the cells of the root tip in prophase at the end of the telophase of mitosis. Explain the results obtained in each phase.

Explanation: Somatic cells contain a diploid set of chromosomes. In the cells of the root tip in prophase, the set of chromosomes and the number of DNA molecules is 2n4c - 56 molecules (since replication has occurred), at the end of the telophase of mitosis - 2n2c - 28 molecules (in daughter cells there are sister single-chromatid chromosomes).

Task 28.

Blood type and Rh factor are autosomal recessive traits.

Blood type is controlled by three alleles of one gene: I0, IA, IB. The IA and IB alleles are dominant to the I0 allele. The first group (0) is determined by the recessive genes I0, the second group (A) is determined by the dominant allele IA, the third group (B) is determined by the dominant allele IB, and the fourth (AB) is determined by two dominant alleles - IAIB. A positive Rh factor (R) dominates a negative factor (r).

The mother has the second blood group and is Rh positive (heterozygous for the Rh factor), the father has the third blood group and is positive for Rh (homozygous for the Rh factor). My son has blood type O and is Rh positive. Make a diagram for solving the problem. Determine the genotypes of the parents and son. Determine what blood groups and Rh factor the children in this family may have, their possible genotypes and the ratio of phenotypes. What law of heredity is manifested in this case?

Explanation: mother's genotype - IAI0Rr

father's genotype - IBI0RR

son's genotype - I0I0R_

P: IAI0Rr x IBI0RR

Gametes: IAR, I0r, IAr, I0R x IBR, I0R

We have the following split into 4 phenotypes and 8 genotypes.

F1: IAIBRR, IAIBRr - fourth blood group, Rh positive

IAI0RR, IAI0Rr - second blood group, Rh positive

IBI0Rr, IBI0RR - third blood group, Rh positive

I0I0Rr, I0I0RR - first blood group, Rh positive

The phenotype ratio is 1:1:1:1.

The law of independent inheritance appears.

Option 7. Biology. A set of materials for preparing students for the Unified State Exam 2018. G.S. Kalinova, L. G. Prilezhaeva.

Forests occupy a huge part of the land on our planet - more than 4 billion hectares of land. Forest ecosystems (FE) are unique communities of animals and plants connected by many types of connections to exchange energy. Main role Plants play a role in any forest ecosystem. According to their dominant species of flora representatives, it is customary to distinguish the following species:

1. Mixed forest ecosystem
2. Ecosystem coniferous forests
3. Ecosystem tropical forests
4. Broadleaf forest ecosystem

For forest ecosystems Tiers are characteristic: trees are located on the top, shrubs make up the middle tier, and grasses form the bottom. The uniqueness of LE can be explained by three factors:

• Firstly, this is practically the only type of ecosystem that has been preserved in its original form and practically unchanged by man.
• Secondly, LEs are among the largest on the planet.
• Thirdly, LEs are considered one of the most productive for humanity.

Let's take a closer look at each type of forest ecosystem.

Mixed forest ecosystem

Mixed forests are a symbiosis of coniferous and deciduous forest ecosystems. They complement each other and strengthen each other, which is why this ecosystem is considered the most stable of all forest ecosystems.

Forests are considered mixed if other species are added to the main type of trees, but in a numerical ratio - no more than 5%. Therefore, such forests are located between coniferous forests in the north and broad-leaved forests in the south - in a strip where the territories of southern Scandinavia, the East European and West Siberian plains, the Carpathians, the Caucasus, the Far East and Southeast Asia are located. On the American continent this is the territory of the Great Lakes and California. In the southern hemisphere, mixed forest ecosystems are found in most of South America and New Zealand.

The dominant trees in this ecosystem are oak, maple, spruce, pine, linden, and elm. In America - sequoia, in the mountains - larch, in the Caucasus and Far East- beech and fir.

Consumers or consumers in the ecosystem of mixed forests are animals, birds, fish, amphibians, insects, and fungi. Gravediggers close the food chain: worms, larvae, microorganisms.

The main feature of a mixed forest ecosystem is sustainability, which is determined by the ability to completely replace the species. That is, if a population of a species disappears, its place is quietly replaced by an increased number of individuals of another species.

The weak point of such an ecosystem is insects. If they disappear, the mixed forest ecosystem will decline and die.

Coniferous forest ecosystem

A cold climate is necessary for the formation of a coniferous forest ecosystem. Therefore, they form mainly in the north, where average air temperature fluctuations range from -5°C to +5°C. There is little precipitation - up to 200 mm per year, and most often it falls in the form of snow. Summer in these parts is cold and short, and winter is long and frosty.

These climatic conditions Perfectly suitable for the growth of coniferous trees: pines, spruces, fir, cedars, larches. They occupy a dominant position in this ecosystem and are located on the upper tier.

Coniferous forests united in massifs are called taiga. This ecosystem is distributed in the northern hemisphere, mainly in Siberia and Canada. In the southern hemisphere, coniferous forests do not create such massifs and are found in separate areas. And in Australia and South America coniferous forests grow in the mountains.

Coniferous trees have needles instead of leaves, which... Due to their small area, they perfectly retain heat and moisture. And the resin that wraps coniferous trees allows you to easily endure prolonged frosts. Photosynthesis in these trees does not stop even at 0°C.

In the ecosystem of coniferous forests there is practically no middle layer. And the lower one is inhabited by mosses and lichens. Together with trees, these types of vegetation are producers - they actively participate in photosynthesis, processing solar energy. In addition, they provide food for the next link in the ecosystem - animals.

The top food chain In such forests there are predators: lynxes, tigers, bears, wolves, foxes. Of the herbivorous mammals, artiodactyls are especially common: deer, elk, wapiti. Many animals with valuable fur: sables, martens, squirrels, weasels. These are consumer organisms.

Destructive organisms include fungi, bacteria and worms.

Food chains in coniferous forest ecosystems are often short. For example, a tree is a herbivore (squirrel) - a predator (fox).

If a person does not interfere in the ecosystem of a coniferous forest, then a process of self-regulation occurs here: one species of animal never completely destroys individuals of another species. What makes this type of ecosystem very resilient.

Broadleaf forest ecosystem

Broad-leaved forests are common throughout much of Europe and East Asia, in North America and south of Chile.

The dominant role is played by deciduous trees - those that shed their leaves with the onset of cold weather. These are linden, oak, ash, elm, maple, chestnut. Bird cherry and birch trees grow on the middle tier. The lower one is completely occupied by herbs and berries: forest grass, lungwort, strawberries, etc.

The consumer class in this ecosystem is represented by mammals (foxes, wolves, tigers, bears, hedgehogs, raccoons, wild boars, hares, squirrels), birds (nightingales, bullfinches, siskins, wood grouse, cuckoos, storks), reptiles, amphibians and fish.

The decomposers are the same gravediggers, worms and microorganisms.

The broadleaf forest ecosystem is very resilient. It becomes vulnerable during cold weather, when trees shed their leaves and the process of photosynthesis stops. During this period, a special role is given to decomposers, which convert organic matter into inorganic substances.

Rainforest ecosystem

Tropical forests encircle our planet along the equator and cover the subtropical, tropical and equatorial climatic zones. In this case, air humidity plays a huge role. In a humid climate, tropical forests are evergreen; in a dry climate (far from oceans and seas), forests are green only in the warm season.

The tropical forest ecosystem is the richest of all forest ecosystems in terms of species diversity. Palm trees, myrtaceae, and legumes dominate here; in the dry tropics - bamboo, laurel, and albizia.

One of the features of the tropical forest ecosystem is the blurring of the boundaries of the layers. Thus, herbs can grow up to 6 m in height, climbing to the middle tier. Ferns can generally occupy all three tiers at once. Adds blurriness and an abundance of vines and epiphytes, which envelop all plants in a dense network.

Another feature of the tropical forest ecosystem is that most species of consumers live directly in the trees. These include numerous animals (monkeys, sloths, flying squirrels), birds (parrots, hummingbirds, woodpeckers, toucans), and reptiles (snakes, lizards, geckos, chameleons). Even frogs try to climb higher. There are few land animals in this ecosystem, but they are all very large: elephants, giraffes, rhinoceroses, hippos, buffalos.

The decomposers are mainly fungi and termites.

Sustainability of forest ecosystems

(Russian Ecosystem Sustainability Scheme)

Among all forest ecosystems, the most stable is the mixed forest ecosystem. Next, in descending order, are deciduous, coniferous and tropical forests.

This is explained by the density of trees and the degree of penetration of sunlight into the lowest tiers of the forest. So, for example, in mixed forests trees do not grow densely, leaving free space for sunlight. The rays penetrate right to the ground, having a significant impact on the activity of decomposers, which, in turn, produce useful material for the growth of the trees themselves.

In coniferous forests, the tops of trees often close together, blocking sunlight. The same thing happens in the tropics, where, due to the abundance of plants, decomposers are simply not able to process such a huge amount of organic matter. Therefore, in the tropics, despite the fact that the plants here produce the most a large number of oxygen, and carbon dioxide is preserved in huge quantities.

The answers to tasks 1–21 are a sequence of numbers, a number or a word (phrase).

1

Consider the proposed scheme. Write down the missing term in your answer, indicated by a question mark in the diagram.

2

Choose two correct answers out of five and write down the numbers under which they are indicated.

The hybridological research method is used

1. embryologists

2. breeders

3. genetics

4. ecologists

5. biochemists

3

An mRNA molecule, a fragment of which contains 33 nucleotide residues, takes part in protein synthesis. Determine the number of nucleotide residues in a section of the DNA template strand.

4

The characteristics listed below, except two, are used to describe the structure, functions, and depicted cell organelle. Identify two characteristics that “fall out” from the general list and write down the numbers under which they are indicated in the table.

1. packages and carries synthesized substances out of the cell

2. participates in the formation of lysosomes

3. provides oxidative phosphorylation

4. consists of one membrane

5. contains interconnected grains

5

Establish a correspondence between the characteristic and the phase of photosynthesis: for each position given in the first column, select the corresponding position from the second column.

CHARACTERISTIC

A. photolysis of water

B. carbon dioxide fixation

B. splitting of ATP molecules

D. excitation of chlorophyll by light quanta

D. glucose synthesis

PHOTOSYNTHESIS PHASE

1. light

2. dark

6

Determine the ratio of phenotypes in the offspring formed by crossing two heterozygous pumpkin plants with yellow fruits with complete dominance. Write your answer as a sequence of numbers showing the ratio of phenotypes in descending order.

7

Below is a list of terms. All of them, except two, are used to describe genetic processes and phenomena. Find two terms that fall out of the general series and write down the numbers under which they are indicated.

1. X chromosome

2. monophyly

3. atavism

5. karyotype

8

Establish a correspondence between the characteristic and the stage of formation of the lancelet embryo: for each position given in the first column, select the corresponding position from the second column.

CHARACTERISTIC

A. invagination of a group of cells into the blastula

B. mitosis of the zygote

B. formation of the walls of the primary intestine

D. formation of blastocoel

D. formation of blastomeres

STAGE OF EMBRYOGENESIS

1. single-layer embryo

2. two-layer embryo

9

Choose three correct answers out of six and write down the numbers under which they are indicated. Angiosperms, as opposed to gymnosperms

1. are perennial plants

3. have flowers and inflorescences

4. form fruits with seeds

5. represented by a variety of life forms

6. reproduce by seeds

10

Establish a correspondence between a vertebrate animal and a feature of its body temperature: for each position given in the first column, select the corresponding position from the second column.

ANIMAL

A. house sparrow

B. sand lizard

V. common dolphin

G. Nile crocodile

D. common newt

E. common mole

FEATURE OF BODY TEMPERATURE

1. constant

2. fickle

11

Establish the sequence of arrangement of systematic groups of plants, starting with the smallest taxon. Write down the corresponding sequence of numbers.

1. Common radish

2. Angiosperms

3. Cruciferous

4. Dicotyledons

12

Choose three correct answers out of six and write down the numbers under which they are indicated. Leukocytes are blood cells that

1. formed in red bone marrow

2. able to change their shape

4. synthesize hemoglobin

5. release substances to form a blood clot

6. ripen in nerve ganglia

13

Establish a correspondence between the example of regulation of vital processes and the department of the nervous system to which it belongs: for each position given in the first column, select the corresponding position from the second column.

EXAMPLE OF REGULATION

A. coordinates the work of internal organs

B. regulates metabolic processes

V. acts autonomously, regardless of a person’s wishes

G. provides voluntary movements of the limbs

D. regulates the activity of smooth muscles

E. regulates skeletal muscle contraction

DEPARTMENT OF THE NERVOUS SYSTEM

1. vegetative

2. somatic

14

Establish the sequence of arrangement of the structures of the eyeball, starting with the cornea. Write down the corresponding sequence of numbers.

1. retinal neurons

2. vitreous body

3. pupil in pigment membrane

4. light-sensitive rod and cone cells

5. convex transparent part of the tunica albuginea

15

Choose three correct answers out of six and write down the numbers under which they are indicated in the table. Which of the following examples are classified as aromorphoses?

1. Functioning of self-sharpening incisors in rodents

2. leaf-shaped body shape of the liver fluke

3. development of stinging cells in hydra

4. the appearance of articulated limbs in insects

5. the appearance of internal fertilization in reptiles

6. emergence of the nodal nervous system in annelids

16

Establish a correspondence between the characteristic of a honey bee and the criterion of the species to which it belongs^ for each position given in the first column, select the corresponding position from the second column.

SIGN OF A HONEY BEE

A. social lifestyle

B. difference in size between males and females

B. development of larvae in honeycombs

D. presence of hairs on the body

D. feeding on nectar and pollen of flowers

E. eyes compound

TYPE CRITERION

1. morphological

2. environmental

17

Choose three correct answers out of six and write down the numbers under which they are indicated. In biogeocenosis, heterotrophs, unlike autotrophs,

1. are producers

2. provide a change of ecosystems

3. increase the supply of molecular oxygen in the atmosphere

4. extract organic matter from food

5. convert organic residues into mineral compounds

6. act as consumers or decomposers

18

Establish a correspondence between the characteristics of the ecosystem and its type: for each position given in the first column, select the corresponding position from the second column.

CHARACTERISTIC

A. various circuits and power networks

B. a wide variety of species

B. presence of monoculture

D. closed cycle of substances

D. instability in time

E. need for additional energy

TYPE OF ECOSYSTEM

1. agrobiocenosis

2. biogeocenosis

19

Establish the sequence of formation of aromorphoses in animals in the process of evolution. Write down the corresponding sequence of numbers.

1. the appearance of internal fertilization

2. occurrence of the sexual process

3. formation of chord

4. formation of five-fingered limbs

20

Look at the picture depicting cell division and determine its phases, the set of chromosomes in the daughter cells, and what specific cells are formed as a result of such division in plants.

Fill in the blank cells of the table using the terms in the list. For each lettered cell, select the appropriate term from the list provided.

List of terms:

1. prophase, metaphase, telophase

2. somatic

3. diploid

4. prophase 2, metaphase 2, anaphase 2, telophase 2

5. prophase 1, metaphase 1, anaphase 1, telophase 1

6. haploid

8. first meiotic division

21

Analyze the graph "Survival of Mouflon at London Zoo." Select statements that can be formulated based on the analysis of the data presented.

Statements:

1. a group of animals consisting of 79 individuals was studied

2. three to four individuals live 118 months

3. born individuals often die in the third year of life

4. most individuals live up to eight years

5. in the original population the average age of individuals is one year

Part 2.

First write down the task number (22, 23, etc.), then the detailed solution. Write down your answers clearly and legibly.

They took several tendrils from one strawberry plant, rooted them and obtained adult plants, which were transplanted to another part of the plantation. However, the fruits of some daughter plants turned out to be smaller than those of the mother plant. Name the method used to propagate strawberries. Explain the reason for the appearance of small fruits.

Show answer

Response elements:

1) the plants were obtained as a result of asexual vegetative propagation;

2) plant differences are due to modification variability associated with differences in environmental conditions in which the daughter and mother plants were grown

Which plant organs are indicated in the figure by the letters A, B, C? What is their role in plant life? What organ are they a modification of?

Show answer

Response elements:

1) A - tuber; B - bulb; B - rhizome;

2) these organs store nutrients, which are used for vegetative propagation;

3) the organs depicted are modified shoots

Find errors in the given text. Indicate the numbers of the sentences in which errors were made and correct them.

1. The endocrine glands have ducts through which the secretion enters the blood. 2. These glands secrete biologically active regulatory substances - hormones. 3. All hormones are proteins by chemical nature. 4. Pancreatic hormone - insulin. 5. It regulates blood glucose levels. 6. With its deficiency, the concentration of glucose in the blood decreases.