At Least Know This: Essential Science to Enhance Your Life Flashcards
What species is a eukaryote, vertebrate, mammal, big-brained, bipedal, omnivorious, microbe-hosting, destructive, spacefaring organism?
You - A human
EVERY organism stores and shares genetic information in ____ and ____.
DNA, RNA
EVERY life form relies on _________ to give its cells structure and help accomodate basic functions.
liquid water
_____, ____, and ____ are the most common elements within all Earth life.
Carbon, oxygen, and nitrogen
Contrary to what our eyes and common sense may tell us, a human body is mostly ____ ____ - because atoms are mostly ___ ___.
empty space
In order of abundance (number of atoms), ___ is the most common element in the universe and in the human body.
hydrogen
In order of mass, ___ is the most common element in the human body followed by ___, then ____.
oxygen, carbon, hydrogen
Hydrogen atoms formed during the Big Bang; all others were forged inside of ____ and then dispersed throughout the universe when those ___ died and exploded in what’s called a supernova event.
stars, stars
Why are we made of so many hydrogen atoms?
because over half our body is water - one water molecule is made of two hydrogen atoms chemically bonded to one oxygen atom
___ are the fundamental unit of life.
Cells
Some life forms do very well with just one cell. Examples include___, ____, and ____.
archaea, bacteria, and protozoa
A recent study estimates 30 trillion cells in an average human body, about ___ are ___ ___ ___.
80%, red blood cells
A human body is 99% hydrogen, oxygen, carbon, and nitrogen atoms. More than half of these are ___, the most abundant element in the universe.
hydrogen
The human body is a diverse and unique habitat for trillions (about 5 lbs worth) of ____, most of which are unknown to science.
microbes (other organisms)
A human body is supported by a bone framework. At birth, a human infant has about ____ bones; many of them later fuse together reducing the total number to ___ in adulthood.
300, 206
The human body is bloody. About ___ percent (1.2-1.5 gallons) of an average person’s weight is blood.
7%
The human body is muscular. There are about ___ named muscles in a human body. There is no agreed upon exact figure, because some muscles are combinations of smaller muscles and can be interpreted differently.
700
The human body is hairy. People are covered by hair. The few hairless areas include ___, ____, and ____.
lips, palms, soles of the feet
Humans are classified in what “domain” of living organisms?
Eukaryota (made of cells with nuclei - like fungi, tubeworms, redwood trees and whales)
Humans are classified in what “phylum” of living organisms?
Vertebrata (you and all other animals with a backbone)
Humans are classified in what “class” of living organisms?
Mammalia (you and all other endothermic animals with spine, hair, and mammary glands)
Humans are classified in what “order” of living organisms?
Primates (lemurs, monkeys, apes, etc.)
Humans are classified in what “genus” of living organisms?
Homo (this includes all forms of humans both alive and extinct)
Humans are classified in what “species” of living organisms?
sapiens (modern humans)
Where do humans fit in with all other life on Earth?
Carl Linnaeus (a Swedish scientist) came up with a helpful way of sorting all life based on similarities and relatedness (called taxonomy). Its like Russian nesting dolls, with “kingdom” being the largest group followed by “phylum”, “class”, “order”, “family”, “genus”, “species”.
Give the categories of taxonomy from most broad to most specific:
kingdom, phylum, class, order, family, genus, species
The ___ or ___ name is the basic naming system for identifying unique life-forms: first comes the larger genus (first letter capitalized, all letters italicized), followed by the smaller species (first letter lowercase, all letters italicized). Example: Homo sapiens
scientific, Latin
The genetic revolution has given scientists a vast resource of detailed information and it (does or doesn’t) always align well with classical taxonomy.
doesn’t
Coral reef ecosystems shelter about a ____ of all marine life. All 29 of the globally significant corals reefs are likely to be dead by the end of this ___.
30%, century
The most comprehensive study ever done on the total volume of Earth life concluded that there are likely ___ species alive right now, and only about ___ percent of them have been identified.
1 trillion, one-thousandth of one percent (0.001 percent)
About ___ percent of all species that have ever lived have gone extinct.
99%
What is life? How do you know if something is living?
There is no universal agreement on the definition of life, and there may never be, given the vague-to-nonexistant boundaries between the living and the nonliving.
The ___ ___ is estimated to contain one of every ten currently known species on Earth. ___ ___ are rapidly destorying it.
Amazon rainforest, Human activities
About ___ percent of plants and trees share a critical symbiotic relationship with fungi. Vast and intricate mycelium networks lay beneath virtually every forest.
90%
About ___ percent of the world’s large carnivores and herbivores are currently threatened with extinction. Iconic animals such as rhinos and giraffes, for example, may be erased from the wild in this century, primarily due to ___ and ___.
60%t, habitat loss and poaching
All known life on Earth today is fundamentally similar, is genetically related, and shares descent from a single-celled common ___ that lived at least ___ or ___ billion years ago.
ancestor, 3 or 4
The question of ___, or how life began, is one of the great challenges in science.
abiogensis
NASA has a deep interest in ____ ____ because astrobiologist are looking for it beyond Earth.
defining life
NASA’s current working definition of life is short and to the point: “__________”
Life is a self-sustaining chemical system capable of Darwinian evolution.
____ meet almost no one’s definition of life because they can’t reproduce alone or with other ____. If one day we were to agree that ___ qualify as life, they would instantly be the most abundant life form in the ocean.
Viruses, viruses, viruses
___ evolved over for billions of years as a consequence of close and constant interactions with plant and animal life, humans included.
Viruses
Ocean viruses kill about ___ of all marine bacteria every 24 hours. Overall, viruses kill about ___ percent of all ocean life every day.
half, 20%
Most ___ are much smaller than bacteria, so the weight almost nothing. But they compensate in numbers. All ocean ____ together weigh more than 75 million blue whales combined.
viruses, viruses
The human genome is about ___ percent viral genes.
5-8%
Viruses may not be capable of fully independent ___ and ___, they do manage to evolve and have a big say in the evolution of everything else.
reproduction and evolution
How old is life on Earth?
The current record holder for the oldest evidence of life are fossils found in Canada that date back 3.95 billion years ago.
What blew up during the Cambrian Explosion?
So many animals showed up. The Cambrian Explosion is the point in geological when complex organisms appeared.
___ are the most iconic of the early marine animals that lived during the Cambrian explosion.
Trilobites
One possible definition of life: sometimes certain kinds of ___ (nonlife) join to become certain kinds of ___ (still not life) that join together to become a ___ (life).
atoms, molecules, cell
Evolution is the consequence of: ___ (life forms have offspring), ___ (offspring are not identical), and ___ (some offspring pass more of their genes on than other offspring).
replication, variation, selection
Evolution is not random: The ___ ___ that create variation are an important part of evolution, and they may be random, but ___ ___ is not random.
genetic mutations, natural selection
The theory of evolution does not claim that humans evolved from modern monkeys and apes. Based on strong ___ and ___ evidence, it seems clear that modern humans, apes, and monkeys shared ___ ___ millions of years ago.
fossil, genetic, common ancestor
Evolution is not synonymous with improvement. There is no ranking of superior or inferior living species in strict evolutionary terms. Evolution is best thought of as the impact of what happened to a ____ over previous ___.
population, generations
Evolution is a ___. Theories are structures of ideas that explain and interpret ___. ___ do not go away while scientists debate theories to explain them.
theory, facts
The human body is not one ____ but a collection of many. For example, 4,154 species of bacteria have been discovered in the ___, and 2,359 behind the ___.
ecosystem, throat, ears
What is “biodiversity”?
a mix of many species
US and Chinese scientists looked at more than a thousand people and revealed a strong connection between very healthy old people and very healthy ___ ___.
gut microbiomes
Older people in good health consistantly have high ___ ___.
microbiome biodiversity
Scientific research strongly indicates that ___ has a positive impact on gut microbes. It seems to increase overall species diversity while also elevating total numbers of beneficial bacteria.
exercise
Microscopic life impacts our ___, ___ ___, ___ ___, and immune system performance, as well as the state of the entire global ecosystem.
mood, sleep patterns, food digestion
Life is never really ___ on this planet. It shares, steals, competes, loves, kills, and cooperates to form complex and overlapping ___.
alone, ecosystems
The universe began ___ billion years ago, providing the time, space, and matter necessary for humans to exist.
13.8
The Sun formed ___ billion years ago providing the energy human life depends on.
4.6
The Earth formed ___ billion years ago.
4.54
The ultimate origin of humans traces back to the beginning of life on Earth, which, based on fossil evidence, is estimated to have occurred at least ___ billion years ago.
4
The first humans (early human species) lived in Eastern and Southern ___ about ___ million years ago.
Africa, 2.5
Modern humans evolved in ___ about ___ years ago.
Africa; 315,000
All people on Earth today are about ___ percent identical to each other (though obviously not clones). Biological races (genetical homogenous populations) don’t exist.
99.9
