August 24, 2017

Biology: Viruses

Virus

A virus is a small, nonliving particle that invades and then reproduces inside a living cell. Viruses are nonliving because viruses are not cells. Viruses also cannot make food, take in food, or produce wastes. Viruses can only multiply when they are inside a living cell.

A host is a living thing that provides a source of energy for a virus or an organism. Organisms that live on or in a host and cause harm to the host are called parasites. Almost all viruses act like parasites because they destroy the cells in which they multiply.


Source: botanystudies.com

Structure of Viruses

All viruses have two basic parts: an outer coat that protects the virus and an inner core made of genetic material. A virus's genetic material. A virus's genetic material contains the instructions for making new viruses.
The coat of a virus plays an important role during the invasion of a host cell. This coat is made of proteins. Each virus contains unique proteins in its coat. The shape of the proteins allows the virus's coat to attach to, or lock onto, certain cells in the host.


How Viruses Multiply

After a virus attaches to a cell, it enters the cell. Once inside, a virus's genetic material takes over the cell's functions. The genetic material directs the cell to produce the virus's proteins and genetic material. These proteins and genetic material are then assembled.

Active Viruses

After entering a cell the virus's genetic material takes over the cell's functions, and the cell quickly begins to produce the virus's proteins and genetic material these parts assemble into new viruses. When it is full of new viruses the host cell bursts open and releases the new viruses.

Hidden Viruses

Virus's genetic material becomes part of the cell's genetic material. The virus's genetic material may stay in this inactive state for a long time.

August 16, 2017

Biology: Protists

Animal-like protists, or protozoans, include sarcodines, ciliates, zooflagellates, and sporozoans. Like animals, these protists are heterotrophs. Most protozoans move by using pseudopods, cilia or flagella.

Funguslike protists include water molds, downy mildews, and slime molds. Like fungi, these protists are heterotrophs, have cell walls, and use spores to reproduce.

Plantlike protists, or algae, include euglenoids, dinoflagellates, diatoms, green algae, red algae, and brown algae. Like plants, these organisms are autotrophs.

Image result for protist

Protozoan
- An animal-like protist.

Pseudopod - A "false foot" or temporary bulge of the cell membrane used for feeding and movement in some protozoans.

Contractile vacuole - The cell structure that collects extra water from the cytoplasm and then expels it from the cell.

Cilia - The hairlike projections on the outside of cells that move in a wavelike manner.

Symbiosis - A close relationship between two organisms in which at least one of the organisms benefits.

Mutualism - A type of symbiosis in which both partners benefit from living together.

Spore - A tiny cell that is able to grow into a new organism.

Algae - A plantlike protist.

Pigment - A colored chemical compound that absorbs light, producing color.

July 28, 2017

Chemistry: Chemical Reactions


Observing Chemical Reactions

A chemical reaction produces materials that have different properties than the starting materials had. Each reaction either absorbs or releases energy.

Color change, production of a gas or a precipitate, a change in temperature, or a change in the properties of a substance are all clues that a chemical reaction has taken place.

Chemical reactions occur when chemical bonds are formed or broken.

  • Precipitate - A solid that forms from a solution during a chemical reaction.
  • Exothermic Reaction - A reaction that releases energy in the form of heat.
  • Endothermic Reaction - A reaction that absorbs energy in the form of heat.


Writing Chemical Equations

A chemical equation uses symbols to show the reactants and products of a chemical reaction.

Matter is neither created nor destroyed during a chemical reaction.

Chemical reactions may be classified by the types of changes in reactants and products:
  • Synthesis - A chemical reaction in which two or more simple substances combine to form a new, more complex substance.
  • Decomposition - A chemical reaction that breaks down a compound into simpler products.
  • Replacement reaction - A reaction in which one element replaces another in a compound, or in which two elements in different compounds trade places.

  • Chemical equation - A short, easy way to show a chemical reaction, using symbols instead of words.
  • Subscript - A number in a chemical formula that tells the number of atoms in a molecule or the ratio of elements in a compound.
  • Reactant - A substance that enters into a chemical reaction
  • Product - A substance formed as a result of a chemical reaction.
  • Conservation of mass - The principle stating that matter is not created or destroyed during a chemical reaction.
  • Coefficient - A number placed in front of a chemical formula in an equation that indicates how many atoms or molecules of each reactant and product are involved in a reaction.


Controlling Chemical Reactions

Every chemical reaction needs activation energy to get started. Endothermic reactions need energy to continue.

The rate of chemical reaction can be controlled by such factors as concentration, surface area, temperature, and use of a catalyst or inhibitor.

  • Activation energy - The minimum amount of energy needed to start a chemical reaction.
  • Catalyst - A material that increases the rate of a chemical reaction by lowering the activation energy.
  • Inhibitor
  • Concentration - The amount of one material dissolved in a given amount of another material.
  • Enzyme - A biological catalyst that lowers the activation energy of reactions in cells.

July 17, 2017

Fizyka: Energia mechaniczna

Energia określa zdolność ciała lub układu do wykonania pracy.
Przyrost energii ciała jest równy wykonanej nad tym ciałem pracy.

Energia potencjalna grawitacji (ciężkości) - równoważna wykonanej pracy - zależy od masy ciała i wysokości, na jaką to ciało zostało wzniesione. Jest to energia ciała wynikająca z jego położenia względem innego ciała, z którym oddziałuje grawitacyjnie, np. Ziemi.

∆E
p = mgh

∆Ep
- przyrost energii potencjalnej ciężkości
m - masa ciała
h - wysokość, na jaką ciało zostało wzniesione
g - przyspieszenie ziemskie równe w przybliżeniu 10 m/s²

Energia kinetyczna ciała (a więc i praca, którą może ono wykonać) jest tym większa, im większą prędkość ma to ciało i im większa jest masa ciała. Jest to energia ciała związana z jego ruchem.

E
k = m∙v²/2


Ek - energia kinetyczna ciała
m - masa ciała
v - prędkość, z jaką porusza się ciało


Energia potencjalna sprężystości - energia, jaką ma odkształcone ciało sprężyste. Przyrost energii potencjalnej sprężystości jest związany z oddziaływaniem międzycząsteczkowym wewnątrz sprężyny.

Energia mechaniczna - suma energii kinetycznej i energii potencjalnej (grawitacji i sprężystości).

Rodzaje energii mechanicznej:
    • Energia potencjalna (grawitacji, sprężystości)
    • Energia kinetyczna (związana z ruchem ciała)
Każda forma energii może ulec przemianie w inny jej rodzaj. Energii nie da się ani zniszczyć , ani stworzyć. Można ją jedynie przekazać lub przekazać innemu ciału.

Określona ilość energii jednego rodzaju może zostać zamieniona w równą ilość energii innego rodzaju.
Oznacza to, że jeżeli dowolny układ ciał nie wymienia energii z otoczeniem, to jego całkowita energia jest stała. Taki układ nazywa się układem izolowanym (odosobnionym). 
Source: szkolnictwo.pl
Zasada zachowania energii
W izolowanym układzie ciał całkowita energia nie ulega zmianie.

E
p + Ek = constans

July 14, 2017

Fizyka: Moc

Moc to liczbowa wielkość fizyczna równa ilorazowi pracy i czasu, w którym ta praca została wykonana.

W określa moc takiego urządzenia, które w czasie 1s wykona pracę 1J:


P = W/t

P
- moc urządzenia (ciała)
W - praca wykonana przez to urządzenie (ciało)
t - czas, w jakim praca ta została wykonana

Inną jednostką mocy jest koń mechaniczny (1KM)

1KM = 736W

P = W/t

a W = F ∙ s,

więc P = F ∙ s/t

Wiadomo, że v = s/t czyli

P = F ∙ V

June 16, 2017

Fizyka: Praca

Energia kinetyczna - Związana z ruchem; im szybciej porusza się dane ciało, tym większą ma energię kinetyczną.
Energia potencjalna grawitacji - Gdy podnosisz ciało na pewną wysokość, zwiększasz jego energię potencjalną. Jest ona tym większa, im wyżej jest ciało.
Energia potencjalna sprężystości - Napięta sprężyna ma pewną energię, dzięki czemu może np. napędzić samochodzik na sprężynę lub zegar mechaniczny.
Energia wewnętrzna - Energia cząsteczek ciała związana z jego temperaturą i stanem skupienia. Gdy podgrzewasz ciało, zwiększasz jego energię wewnętrzną.
Energia chemiczna - Spalając węgiel czy benzynę, wyzwala się zawartą w nich energię. Jest to główne źródło energii dla ludzkości. Każdy z nas żyje dzięki energii zawartej w pożywieniu.
Energia elektryczna - Jest to postać energii najłatwiejsza do przesyłania i zamiany na inne rodzaje. Dlatego większość urządzeń jest zasilana właśnie tą energią.
Energia jądrowa - Korzysta się z niej w elektrowniach jądrowych. Także Słońce świeci dzięki przemianom jądrowym zachodzącym w jego wnętrzu.
Energia promieniowania - Światło, mikrofale w kuchence mikrofalowej, ultrafiolet powodujący opalanie, promienie rentgenowskie używane do prześwietleń, fale radiowe - wszystkie niosą pewną energię.


Iloczyn wartości siły i wartości przemieszczenia, które nastąpiło zgodnie z kierunkiem i zwrotem działania siły.

W=F∙s

W - Praca
F - siła
s - droga

Podstawową jednostką pracy w układzie SI jest dżul (1J).

[W] = 1J

Praca ma wartość 1J, gdy siła 1N działająca na ciało ma wartość 1N, a przemieszczenie zgodne z kierunkiem i zwrotem siły wynosi 1m.

1J = 1N
1m


Jeśli na ciało działa dowolna siła zgodna z kierunkiem i zwrotem przemieszczenia, to wykonana praca jest liczbowo równa polu figury pod wykresem zależności siły od przemieszczenia.

source: Szkolnictwo.com

June 14, 2017

Fizyka: Pęd

Pęd ciała - wielkość wektorowa o kierunku i zwrocie zgodnym z kierunkiem i zwrotem wektora prędkości. Wartość pędu jest równa iloczynowi masy ciała i wartości prędkości.

Przyjmij, że siły
F1 = F2 są stałe i działają przez czas t, a masy ciał wynoszą odpowiednio m1 = m2
Na podstawie II zasady dynamiki wiadomo, że między obydwiema siłami oraz przyspieszeniami, z jakimi poruszają się ciała, zachodzą zależności:

F1 = m1∙a2
F1 = m1a2

↑Wartość tych sił są równe↑

Przy założeniu, że przed działaniem sił ciała znajdowały się w spoczynku, można obliczyć, jakie zmiany wartości prędkości nastąpiły pod wpływem tych sił w tym samym czasie t

Jeżeli dwa ciała oddziałują wyłącznie na siebie nawzajem (nie działają na nie żadne siły zewnętrzne), to zmiana pędu jednego ciała powoduje taką samą co do wartości zmianę pędu ciała drugiego, lecz o przeciwnym zwrocie. Taki układ jest przykładem układu izolowanego od otoczenia.

p=mv

p - pęd
m - masa
v - prędkość

Pęd ciała jest wielkością wektorową.
 Kierunek i zwrot pędu jest taki sam jak kierunek i zwrot prędkości ciała. 

source: Wikipedia

Zasada zachowania pędu
Całkowity pęd układu, na który nie działają siły zewnętrzne, nie zmienia się.

May 30, 2017

Six Kingdoms: Bacteria

BACTERIAL CELL
Bacteria are prokaryotic. The genetic material in their cells is not contained in a nucleus.
Each bacterial cell uses energy, grows and develops, responds to its surroundings, and reproduces.



SHAPE OF A BACTERIAL CELL 
Bacteria have three basic shapes: spherical, rodlike, or spiral. The shape of bacterial cell is determined by the chemical makeup of its outermost structure - the cell wall which is rigid and helps to protect the cell.

STRUCTURE OF A BACTERIAL CELL
Inside the cell wall is the cell membrane, which controls what materials pass into and out of the cell.
Inside the cell membrane, the cytoplasm contains a gel-like material. Ribosomes, the sites where proteins are produced, are located in the cytoplasm. The cell's genetic material, which looks like a thick, tangled string, is also located in the cytoplasm.
The genetic material contains the instructions for all the cell's functions, such as how to produce proteins on the ribosomes.
A flagellum is a long, whiplike structure that extends from the cell membrane and passes through the cell wall. A flagellum helps a cell to move by spinning in place like a propeller. A bacterial cell can have many flagella, one, or none. Most bacteria that do not have flagella cannot move on their own.

Source: Boundless.com


TWO KINGDOMS OF BACTERIA
Archaebacteria - Many live in extreme environments, such as: hot springs, intestines, sewage etc. 
Eubacteria - Most do not live in extreme environments.


REPRODUCTION IN BACTERIA
When bacteria have plenty of food, the right temperature, and other suitable conditions they thrive and reproduce frequently.

Asexual Reproduction
Bacteria reproduce by binary fission, a process in which one cell divides to form identical cells. Asexual reproduction is a reproductive process that involves only one parent and produces offspring that are identical to the parent. In binary fission, the cell first duplicates its genetic material and then divides into two separate cells. Each new cell gets its own complete copy of the parent cell's genetic material as well as some of the parent's ribosomes and cytoplasm.

Sexual Reproduction
Sexual reproduction called conjugation, involves two parents who combine their genetic material to produce a new organism which differs from both parents. During conjugation one bacterium transfers some of its genetic material into another bacterial cell through a thin, threadlike bridge that join the two cells. After the transfer, the cells separate. Conjugation results in bacteria with new combinations of genetic material.


OBTAINING FOOD
Some bacteria are autotrophs and make their own food. Autotrophic bacteria make food in one of two ways: by capturing and using the sun's energy as plants do or by using the energy from chemical substances in their environment. 
Some bacteria are heterotrophs - they obtain food by consuming autrophs or other heterotrophs.


RESPIRATION
Respiration is the process of breaking down food to release its energy. 
Most bacteria need oxygen to break down their food, but a few kinds of bacteria do not need oxygen for respiration.


ENDOSPORE FORMATION
Some bacteria can survive harsh conditions by forming endospores which are small, rounded, thick-walled, resting cells that form inside a bacterial cell. They contain the cell's genetic material and some of its cytoplasm.


BACTERIA IN THE LIVING WORLD
Bacteria are involved in fuel and food production as well as in environmental recycling and cleanup. However, some bacteria do cause diseases and other harmful effects.

Fuel
The archaebacteria that live in oxygen-free environments, such as the thick mud at the bottom of a lake or swamp, produce a gas called methane.

Food
The activities of helpful bacteria produce, cheese, yogurt, apple cider, olives and sauerkraut. But some bacteria cause food to spoil when they break down the food's chemicals.

source: eatwisconsincheese.com
Environmental Recycling
Heterotrophic eubacteria which live in the soil, are decomposers - organisms that break down large chemicals in dead organisms into small chemicals and then return basic chemicals to the environment for other living things to reuse. Other recycling eubacteria live in swellings on the roots of some plants, such as peanuts and soybeans. There, they convert nitrogen gas from the air into nitrogen compounds that the plants need to grow.

Environmental Cleanup
Some bacteria help to clean up Earth's land and water. Scientists have put these bacteria to work cleaning oil spills in oceans and gasoline leaks around gas stations.

source: CNN
Health
An antibiotic is a chemical that can kill bacteria without harming a person's own cells. 

Source: Young scientist journal 

May 3, 2017

Biology: Taxonomy

Animals are classified in 7 levels: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.


Source: Wikipedia

Spotted Hyena

Source: BBC
Domain: Animalia
Kingdom: Chordata
Class: Mammalia
Order: Carnivora
Family: Hyaenidae
Genus: Crocuta
Species: Crocuta Crocuta

April 24, 2017

Zasady dynamiki Newtona I i II

I  ZASADA DYNAMIKI NEWTONA

Jeżeli na ciało nie działają żadne siły lub działające siły się równoważą, to ciało pozostaje w spoczynku lub porusza się ruchem jednostajnym prostoliniowym.

II  ZASADA DYNAMIKI NEWTONA

Jeżeli na ciało działa niezrównoważona siła, porusza się ono ruchem zmiennym z przyspieszeniem wprost proporcjonalnym do działającej siły. Przyspieszenie ciała, na które działa stała niezrównoważona siła, jest tym mniejsze, im większa jest jego masa:
a = F/m


F - wartość siły
m - masa ciała
a - przyspieszenie ciała

1 N jest to siła, która ciału o masie 1 kg nadaje przyspieszenie 1 m/s².

Source: Physics4kids


Przyspieszenie ciała, na które działa niezrównoważona siła, jest wprost proporcjonalne do działającej siły.
Przy danej wartości siły działającej na ciało przyspieszenie jest tym mniejsze, im większa jest masa ciała.

Spadające swobodnie ciała poruszają się ruchem jednostajnie przyspieszonym. Przyspieszenie, z jakim w pobliżu Ziemi porusza się swobodnie ciało, nazywa się przyspieszeniem ziemskim.

g≈9,81 m/s²

Fg=mg

Fg - siła ciężkości (grawitacji)
m - masa ciała
g - przyspieszenie ziemskie

Czas swobodnego spadania ciała nie zależy od jego masy.

Masa jest miarą bezwładności ciała.

April 23, 2017

Satellites and Centripetal force

A satellite is any object that travels around another object in space.
An artificial satellite is a device launched into orbit around Earth. Artificial satellites are designed for many purposes. They are used in space research, communications, military intelligence, weather analysis, and geographical surveys.

Source: Wikipedia

Any force that causes an object to move in a circle is called a centripetal force ("center seeking").

An object traveling in a circle is accelerating because it is constantly changing direction. For a satellite the centripetal force is the gravitational force that pulls the satellite toward the center of the Earth.

Source: Science for Kids 

Satellites in orbit around Earth continually fall toward Earth, but because Earth is curved they travel around it. In other words, a satellite is a projectile that falls around Earth rather than into it. A satellite does not need fuel because it continues to move ahead thanks to its inertia. At the same time, gravity continuously changes the satellite's direction.
The speed with which an object must be thrown in order to orbit Earth turns out to be about 7,900m/s!

April 5, 2017

Newton's Third Law of Motion

If one object exerts a force on another object, then the second object exerts a force of equal strength in the opposite direction on the first object.

MOMENTUM = Mass × Velocity

The unit for momentum is kilogram-meters per second (kg⁤∗ms/s). Like velocity and acceleration, momentum is described by its direction as well as its quantity.

Law of Conservation of Momentum
The total momentum of any group of objects remains the same unless outside forces act on the object.

Source: successify.net


February 6, 2017

Biology: Advances in genetics

Methods that people have used to develop new organisms with desirable traits are:
  • Selective breeding
                selecting a few organisms with desired traits to serve as parents of the next generation.
  • Inbreeding
                crossing two individuals that have identical or similar sets of alleles. The new organisms are very similar to those of their parents.
  • Hybridization
                crossing two genetically different individuals. The hybrid organism that results is bred  to have the best traits from both parents.
  • Cloning
               a clone is an organism that is genetically identical to the original organism it was produced from. A clone  has exactly the the same genes as the parent organism.
  • Genetic Engineering
               in this  process genes from one organism are transferred into the DNA of another organism.
Dolly, the first cloned sheep.
Source: Daily Mail

The Human Genome Project:
A genome is all the DNA in one cell of an organism.
The main goal of the Human Genome Project is to identify the DNA sequence of every gene in the human genome.


January 19, 2017

Airbus Families

A350XWB


A350-800

Range: 15,200km
Passengers (Typical Seating): 280
Max Payload: 12.95t
Wing Span: 64.75m
Overall length: 60.54m
Height: 17.05m
Engine: 2x RR Trent XWB
Max fuel capacity: 138,000L

A350-900
Range: 15,000km
Passengers (Typical Seating): 325
Max Payload: 16t
Wing Span: 64.75m
Overall length: 66.8m
Height: 17.05m
Engine: 2x RR Trent XWB
Max fuel capacity: 138,000L

A350-1000
Range: 14,800km
Passengers (Typical Seating): 366
Max Payload: 20.89t
Wing Span: 64.75m
Overall length: 73.78m
Height: 17.08m
Engine: 2x RR Trent XWB
Max fuel capacity: 156,000L

A380


Range: 15,200km
Passengers (Typical Seating): 544
Max Payload: - t
Wing Span: 79.75m
Overall length: 72.72m
Height: 24.09m
Engine: 4x GP 7200, or RR Trent 900
Max fuel capacity: 320,000L

A320

A318
Range: 5,750km
Passengers (Typical Seating): 107
Max Payload: 11.1t
Wing Span: 34.10m
Overall length: 31.44m
Height: 12.56m
Engine: 2x PW6000A, or CFM56-5B
Max fuel capacity: 24,210L

A319
Range: 6,950km (with Sharklets)
Passengers (Typical Seating): 124
Max Payload: 13.2t
Wing Span: 35.80m
Overall length: 33.84m
Height: 11.76m
Engine: 2x CFM56-5B, or V2500-A5
Max fuel capacity: 30,190L

A320
Range: 6,100km (with Sharklets)
Passengers (Typical Seating): 150
Max Payload: 16.6t
Wing Span: 35.80m
Overall length: 37.57m
Height: 11.76m
Engine: 2x V2500-A5, or CFM56-5B
Max fuel capacity: 27,200L

A321
Range: 5,950km (with Sharklets)
Passengers (Typical Seating): 185
Max Payload: 21.2t
Wing Span: 35.80m
Overall length: 44.51m
Height: 11.76m
Engine: 2x V2500-A5, or CFM56-5B
Max fuel capacity: 30,030L

A330

A330-200
Range: 13,450km
Passengers (Typical Seating): 247
Max Payload: 36,4t
Wing Span: 60.30m-]
Overall length: 58.82m
Height: 17.39m
Engine: 2x PW4000, GE CF6-80E1, or RR Trent 700-]
Max fuel capacity: 139,090L

A330-300
Range: 11,750km
Passengers (Typical Seating): 277
Max Payload: 45.9t
Wing Span: 60.30m
Overall length: 63.69m
Height: 16.83m
Engine: 2x PW4000, GE CF6-80E1, or RR Trent 700
Max fuel capacity: 97,530L

A340

A340-200
Range: 12,400km
Passengers (Typical Seating): 261
Max Payload: 30.8t
Wing Span: 60.30m
Overall length: 59.4m
Height: 16.80m
Engine: 4x CFM56-5C4/P
Max fuel capacity: 155,040L

A340-300
Range: 13,500km
Passengers (Typical Seating): 277
Max Payload: 43.5t
Wing Span: 60.30m
Overall length: 63.69m
Height: 16.91m
Engine: 4x CFM56-5C4/P
Max fuel capacity: 140,640L

A340-500
Range: 16,670km
Passengers (Typical Seating): 293
Max Payload: 43.3t
Wing Span:63.45m
Overall length: 67.93m
Height: 17.28m
Engine: 4x RR Trent 500
Max fuel capacity: 215,260L

A340-600
Range: 14,450km
Passengers (Typical Seating): 326
Max Payload: 55.6t
Wing Span:63.45m
Overall length: 75.36m
Height: 17.22m
Engine: 4x RR Trent 500
Max fuel capacity: 195,520L

With all the information above i made this small project:






All information and images above are from Airbus.com

January 17, 2017

Biology: Walter Sutton and inheritance


Walter Sutton


Walter Sutton - (1877-1916) was an American geneticist who studied the cells of grasshoppers. He was trying to figure out how sex cells form. During his studies, he examined  sex cells many different stages of formation. He was interested in the movement of chromosomes during the formation of sex cells. He said that chromosomes were the key to understanding how offspring come to have traits similar to those of their parents.
Chromosomes carry Mendel's hereditary factors, from one generation to the next. In other words, genes are located on chromosomes.

Chromosome Theory of Inheritance 
Genes are carried from parents to their offspring on chromosomes.

Meiosis is the process by which the number of chromosomes is reduced by half to form sex cells-sperm and eggs.
During meiosis, the chromosome pairs separate and are distributed to two different cells. The resulting sex cells have only half as many chromosomes as the other cells in the organism.

Chromosomes
Chromosomes are made up of many genes joined together like beads on a string.
Although humans have only 23 pairs chromosomes, your body cells contain more than 60,000 genes. Each of the genes controls a particular trait.

January 15, 2017

Physics: Friction and Gravity

The strength of the force of friction depends on two factors: the types of surfaces involved and how hard the surfaces push together.


il_fullxfull.250203781There are different kinds of friction:
  • sliding friction - when one solid surface slides over another.
  • rolling friction - when a object rolls over a surface.
  • fluid friction - when an object moves through a fluid. 


Gravity

Free fall - when the only force acting on a falling object is gravity.
Terminal velocity -  the maximum velocity a falling object achieves.


January 4, 2017

Newton's First and Second Law of Motion

Newton's First Law of Motion
Law of inertia

An object at rest will remain at rest and an object that is moving at constant velocity will continue moving at constant velocity unless acted upon by an unbalanced force.

Newton's Second Law of Motion

The net force on an object is the product of its acceleration and its mass.

F = ma

F - Force
m - mass
a - acceleration 

1N = 1kg  1m/s²


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January 3, 2017

Biology: Gregor Mendel - intro to genetics



Trait: A characteristic that an organism can pass on to its offspring through its genes.

Gene: A segment of DNA on a chromosome that codes for a specific trait.

Alleles: The different forms of gene.

Dominant alleles: An allele whose trait always shows up in the organism when the allele is present.

Recessive alleles: An allele that is masked when a dominant allele is present.

Hybrid: An organism that has two different alleles for a trait (heterozygous organism).

Gregor Mendel oval.jpgGregor Mendel (1822-1884) - Austrian scientist, priest, teacher. He studied genetics with his pea plants in the monastery. And wrote a report why some peas are tall and some are short.  Back in his days no one believed his theory. Now he is considered the father of modern genetics.