L.E Notsi Secondary School 2019

09/06/2020

Write your own Essay

19/07/2019

Natural selection is the differential survival and reproduction of individuals due to differences in phenotype.
💪It is a key mechanism of evolution, the change in
the heritable traits characteristic of apopulation over generations.
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Charles Darwin popularised the term natural selection contrasting it with artificial selection, which in his view is intentional, whereas natural selection is not.
Variation exists within all populations of organisms.
This occurs partly because random mutations arise in the gene of an individual organism, and offspring can inherit such mutations.
Throughout the lives of the individuals, their genomes interact with their environments to cause variations in traits.
The environment of a gene includes the molecular biology in the cell, other cells, other individuals, populations, species, as well as the abiotic environment.
Because individuals with certain variants of the trait tend to survive and reproduce more than individuals with other, less successful variants, the population evolves.
Other factors affecting reproductive success include s*xual selection (now often included in natural selection) and fecundity selection.
Natural selection acts on the phenotype, the characteristics of the organism which actually interact with the environment, but the genetic (heritable) basis of any phenotype that gives that phenotype a reproductive advantage may become more common in a population.
Over time, this process can result in populations that specialise for particular ecological niches (microevolution) and may eventually result in speciation (the emergence of new species, macroevolution).
In other words, natural selection is a key process in the evolution of a population.

Natural selection in action
.....PICTURE BELOWN........

The general sense of change over time.

All life forms have descended with modifications from ancestors in a process of common descent.
The cause or mechanisms of these process of change, that are examined and explained by evolutionary theories.
A fact is a hypothesis that is so firmly supported by evidence that we assume it is true, and act as if it were true.
Scientists most often use the word fact to describe an observation.
But scientists can also use fact to mean something that has been tested or observed so many times that there is no longer a compelling reason to keep testing or looking for examples. The occurrence of evolution in this sense is a fact.
Scientists no longer question whether descent with modification occurred because the evidence supporting the idea is so strong.
The scientific definition of the word theory is different from the definition of the word in colloquial use. In the vernacular,theory can refer to guesswork, a simple conjecture, anopinion, or a speculation that does not have to be based on facts and need not be framed for making testable predictions.
In science, however, the meaning of theory is more rigorous.
A scientific theory is a well-substantiated explanation of some aspect of the natural world that can incorporate facts,laws, inferences, and testedhypotheses.
Theories are formed from hypotheses that have been subjected repeatedly to tests of evidence which attempt to disprove or falsify them.
In the case of evolution through natural selection, Darwin conceived the hypothesis around 1839, and made a first draft of the concept three years later in 1842.
He discussed this widely with many of his intellectual companions, and conducted further research in the background to his other writings and work.
After years of development, he finally published his evidence and theory in On the Origin of Species in 1859.

19/07/2019

Core-periphery...
Core periphery structure is based on Immanual Wallersteins world- systems theory.
He formulated the chart in the 1980s. Core are the MEDCs in the world and the periphery the major section are the LEDCs that are not as developed as MDCs but are very slowly starting to develop.

19/07/2019

🌐DNA Replication🌐

🔹DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule.
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🔹DNA replication occurs in all living organisms acting as the basis for biological inheritance.
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🔹The cell possesses the distinctive property of division, which makes replication of DNA essential.
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🔷DNA is made up of a double helix of two complementary strands.
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👽DNA replication
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🔰The double helix is unzipped and unwound,

🔰then each separated strand (turquoise) acts as a template for replicating a new partner strand (green).

🔰Nucleotides (bases) are matched to synthesize the new partner strands into two new double helices.

↕An image of the 46 chromosomes making up the diploid genome of a human male.
(The mitochondrial chromosome is not shown.)

↔The genome includes both the genes (the coding regions) and the non-coding DNA, as well as mitochondrial DNA and chloroplast DNA.
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Reproduction System

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👿Sexual reproduction↔ is a type of life cycle where generations alternate between cells with a single set of chromosomes (haploid) and cells with a double set of chromosomes (diploid).

👙In the first stage of s*xual reproduction, meiosis the number of chromosomes is reduced from a diploid number (2n) to a haploid number(n).

👙During fertilization haploid gametes come together to form a diploid zygote and the original number of chromosomes is restored.
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These are the basic tenets of evolution by natural selection as defined by Darwin:🐢🐂

🐳More individuals are produced each generation than can survive.

🐳Phenotypic variation exists among individuals and the variation is heritable.

🐳Those individuals with heritable traits better suited to the environment will survive.

🐳When reproductive isolation occurs new species will form.
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💛SPECIATION💛
🍋Sexual selection is a mode of natural selection where members of one biological s*x choose mates of the other s*x to mate with (inters*xual selection), and compete with members of the same s*x for access to members of the opposite s*x (intras*xual selection).
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♣CONCEPT

♦Chromosome🎬is a deoxyribonucleic acid (DNA) molecule with part or all of the genetic material (genome) of an organism
♦ Population is all the organisms of the same group or species, which live in a particular geographical area, and have the capability of interbreeding.

19/07/2019

18/07/2019

😇ECONOMIC GEO😇
The three-sector model in economics divides economies into three sectors of activity:
extraction of raw materials 💃(primary), manufacturing 💃(secondary), and services 💃(tertiary).
💃According to the model, the main focus of an economy's activity shifts from the primary, through the secondary and finally to the tertiary sector.
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💙Economic geography💙
⚫study of the location, distribution and spatial organization of economic activities
⚫The geography of people making a living, dealing with the spatial patterns of production, distribution and consumption of goods and services.
⚫The development of economic geography over the past three decades has witnessed the substitution of analysis for description, leading to an identification of the factors and an understanding of the processes affecting the spatial differentiation of economic activities over the earth's surface.
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🔴Economic geography has been defined by the geographers as the study of human's economic activities under varying sets of conditions which is associated with production, ❤location, distribution, consumption, exchange of resources, and spatial organization of economic activities across the world.
🔴It represents a traditional subfield of the discipline of geography.

However, many economists have also approached the field in ways more typical of the discipline of 💙economics.
Economics focuses on the behaviour and interactions of economic agentsand how economies work.
❤ location and place are used to identify a point or an area on the Earth's surface or elsewhere.

The term location generally implies a higher degree of certainty than place, the latter often indicating an entity with an ambiguous boundary, relying more on human or social attributes of place identity and sense of place than on geometry.
💛Geography is often defined in terms of two branches: human geography and physical geography.

Human geography deals with the study of people and their communities, cultures, economies, and interactions with the environment by studying their relations with and across space and place.
Physical geography deals with the study of processes and patterns in the natural environment like the atmosphere,hydrosphere, biosphere, and geosphere.
💙Economics is the social science that studies the production, distribution, and consumption of goods and services.
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Spatial Data
Data that is represented by 2D or 3D images.
Spatial data can be further subdivided into geometric data (data that can use calculations involving Euclidian geometry) and geographic data (data that identifies geographic locations and boundaries on the earth).
Data that is represented by 2D or 3D images.

02/07/2019

☺😊😀😁😂😃😄😅😆😇😈😉😯😐😴😡😬😠
Darwin&apos
Theory of evolution is based on key facts and the inferences drawn from them, which biologist Ernst May summarised as follows:

Every species is fertile enough that if all offspring survived to reproduce, the population would grow (fact).
Despite periodic fluctuations, populations remain roughly the same size (fact).
Resources such as food are limited and are relatively stable over time (fact).
A struggle for survival ensues (inference).
Individuals in a population vary significantly from one another (fact).
Much of this vaiation is heritable(fact).
individuals more suited to the environment are more likely to survive and more likely to reproduce and leave their heritable traits to future generations, which produces the process of natural selection (fact).
This slowly effected process results in populations changing to adapt to their environments, and ultimately, these variations accumulate over time to form new species (inference).

28/06/2019

Future kings and Queens
Our target is 100%

Plz