Science Flashcards
Over the next 3,000 million years, life remained relatively simple, progressing from microscopic to visible forms—this whole time is termed by geologists the … .
Precambrian
The Precambrian is the earliest part of Earth’s history
Occurred: 4,600 million years ago - 541 (+/- 1) million years ago
(The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth’s geologic time.)
the scientist who study of weather conditions
Meteorologist
The idea of continental drift was proposed by the German meteorologist Alfred Wegener (1880–1930) in 1912, based on two lines of evidence.
The idea of continental drift was proposed by the German meteorologist Alfred Wegener (1880–1930) in 1912, based on two lines of evidence. First, he noted the close match of the coastlines on the Atlantic Ocean, and how, for example, the east coast of South America “fitted” the west coast of Africa. His suggestion that the Atlantic had once not existed, and that all continents had been joined as one great supercontinent, termed ………….
Pangea
(Ancient Greek for “all world”), was confirmed by his observation of shared rocks and fossils across southern lands dating to the Permian and Triassic, some 250 million years ago.
6.5 MYA First possible hominin ancestor
sahelanthropus
Most of our understanding of the ape-like human relatives , Sahelanthropus tchadensis, who lived between 6 and 7 million years ago,comes from this virtually complete fossil skull, found in the desert sands of Chad in the southern Sahara. The skull combines primitive ape-like features with some more advanced, human-like ones.
Helght: 1m (3ft 3in)
body weight: not known
brain volume: 360-370ml
the remains of once-living organisms, plants, animals, or microbes.
Fossil
Fossils are the key to dating rocks, but more importantly they reveal the history of life. Human fossils can show us astonishing detail of ancient anatomy, diet, locomotion, and behavior.
(Latin fossilis ‘dug up’, from fodere ‘dig’)
this scientist proposed the theory of continental drift – the idea that Earth’s continents move.(published in 1915)
Alfred Wegener (1880-1930)
In 1915 Alfred Wegener’s seminal work describing the continental drift was first published in German. Wegener explained various phenomena of historical geology, geomorphy, paleontology, paleoclimatology, and similar areas in terms of continental drift.
thanks to evolution, we retain so much in common with our nearest relatives, the chimps - a remarkable ……. per cent of our gnome.
98.8
an animal with two legs, such as a human
biped
Latin bipes, from bi- + pes “foot”
in a biological sense is simply change through time.
Evolution
And very importantly, that is change through time over generations. So for example, the human species, hundreds or thousands of years ago was much shorter than it is today. Over the course of those generations, the human species has grown taller. That change is an evolutionary change. In contrast, I used to be a baby. Now I’m an adult. That change is not an evolutionary change because it happened within an individual. That change is development instead.
(Coursera: Introduction to Genetics and Evolution)
the way in which members of a family are descended from other members
lineage
evolution has two fundamental processes. So you can have change within a lineage. The other fundamental process within evolution is the formation of new lineages, or this idea of common ancestry of species.
Much of Evolutionary change was caused by ….. …., which produces the appearance of design.
natural selection
All spieces share …. …., resualt of spliting lineages from one ancestral life form.
common ancestry
J.B.S.Haldane once said:
“I will give up my belief in evolution if someone finds a … … in the Precambrian.”
fossil rabbit
organs which don’t have a function in present-day species
vestigial organ
Latin vestigium, meaning “footprint, trace.”
(chiefly of animals) living in trees
arboreal
Was it climate change that propelled our supposed arboreal ancestors from the forests onto the ground in the savannas, setting in motion a series of complex anatomical changes?
Latin arboreus, from arbor ‘tree’
Swedish botanist, zoologist, taxonomist, and physician who is most famous for creating a system of naming plants and animals
Carl Linnaeus
in 1748, humans officially became animals for the first time.In his book Systema Naturae** (The System of Nature), the botanist and zoologist **Carl Linnaeus (1707-78) placed us in a group of related animal species –a genus–that he called Homo, and classified us as sapiens, meaning “wise.” Today, Homo sapiens is the only exisiting human form.
has been considered a plausible ancestor for primates since it was discovered
Purgatorius
Where did primates come from? We don’t know, but 70 million years ago, when dinosaurs dominated Earth, there also existed a proto-primate called Purgatorius, a small animal the size of a mouse. So once the dinosaurs disappeared, modern mammals, including primates, were able to multiply their numbers.
member of the group of animals from which human beings have developed
hominid
we can define the hominid family as all of the great apes that have a humanlike form and the same ability to walk on two legs.
the smallest unit of life
cell
cells are the smallest things that show all the six characteristics that scientists say define life.
Latin cella ‘storeroom or chamber’.
The six Characteristics of Living Things
- They require energy.
- They reproduce.
- They display heredity.
- They respond to stimuli.
- They evolve and adapt.
- They maintain homeostasis.
source: © 2022 Cengage Learning, Intoduction to Biology
an animal’s baby or babies
SYN young
offspring
The living things reproduce. Living things make offspring. Sometimes they make eggs and sperm to allow for sexual reproduction, or sometimes they make exact copies of themselves to spread asexually.
the process by which mental and physical qualities are passed from a parent to a child before the child is born
heredity
The living things display heredity. Offspring inherit their characteristics from their parents.
from Latin hereditas ‘heirship’, from heres, hered- ‘heir’.
وراثت، انتقال موروثی،برماند، مانداک، توارک
are made of groups of tissues.
Organ
Each organ does a specific task or group of tasks for the body. For example, cardiac muscle tissue combines with other tissues to form the organ we know as the heart.
from Greek organon ‘tool, instrument, sense organ’,
something that produces a reaction in a human, an animal or a plant
stimulus (Plural: “stimuli” )
The living things respond to stimuli. If you yell “Boo!” at a rock, it just sits there; yell “Boo!” at a bird, and it flies away.
keeping conditions steady around a set point
homeostasis
The living things maintain homeostasis. Homeostasis means keeping conditions steady around a set point. For example, a thermostat in your home maintains the temperature of a room. You set the thermostat for the temperature you want. When the temperature falls below a certain point, the thermostat turns on the heater to warm up the room. When the temperature rises above a certain point, the heater turns off. The room temperature stays within a certain range.
from Greek homoios ‘like’ + statsis ‘standing, stoping”
it form when cells that have similar structures and functions attach.
tissue
For example, muscle cells attach to each other to form muscle tissue. One special type of muscle tissue in your body is cardiac muscle tissue.
In 1665, an English scientist named … … became the first person to ever see cells when he used a microscope to look at thin slices of a plant tissue called cork.
Robert Hooke
In science, a ….. is an idea that’s well supported by multiple lines of evidence.
theory
So calling something a theory is scientists’ way of saying, “We’ve worked really hard to figure this out, and this is our best explanation for how this works.” A scientific theory represents a lot of research and evidence.
from Greek thea“a view” (see theater) + horan “to see,”
(By contrast, most people use the word theory in common conversation to mean a hunch or guess, as in, “I’ve got a theory about who keeps leaving their wet towels on the bathroom floor.” (A scientist’s word for a hunch or an educated guess is hypothesis.)
the scientific study of life on other planets
astrobiology
some scientists have other hypotheses, like the idea that life may have traveled to Earth from an extraterrestrial source. In fact, a whole field of science called astrobiology looks for evidence of life in outer space.
Greek ἄστρον, astron, “constellation, star”; βίος, bios, “life”; and -λογία, -logia, study.
book title:
Harvard’s top astronomer lays out his controversial theory that our solar system was recently visited by advanced alien technology from a distant star.
Extraterrestrial: The First Sign of Intelligent Life Beyond Earth –
by Avi Loeb– Jan. 26 2021
icy rocks that exist in the outskirts of the solar system
comet
Comets are very loosly bound to the Sun, when one of them comes close to the sun, the ice evaporates and you end up with a cometary tail, a trail of gas and dust, following around the object.
Greek kometes “long-haired, comet”, from kome “hair”; because of its long tail
(نجوم) ستاره ی دنباله دار، استاره، ذوذنب، شهاب سنگ
The first known interstellar object to visit our solar system
ʻOumuamua
1I/2017 U1 ‘Oumuamua, was discovered Oct. 19, 2017 by the University of Hawaii’s Pan-STARRS1 telescope, funded by NASA’s Near-Earth Object Observations (NEOO) Program, which finds and tracks asteroids and comets in Earth’s neighborhood.
name comes from Hawaiian ʻoumuamua ‘scout’ or “messenger”
a minor planet of the inner Solar System
asteroid
Asteroids, sometimes called minor planets, are rocky remnants left over from the early formation of our solar system about 4.6 billion years ago.
Greek asteroeides “like a star”, from aster “star”
سیارک … خرده سیاره
the first astronomer who suggested the Earth orbited the Sun
Galileo Galilei
pioneering French biologist who is best known for his idea that acquired characters are inheritable
Jean-Baptiste Lamarck (1744-1829)
Although the name “Lamarck” is now associated with a discredited view of evolution, the French biologist’s notion that creatures evolved by developing certain traits over their life time and passing those on to their offspring. In fact, the “inheritance of acquired characters” continued to have supporters well into the 20th century.
the philosopher_acientist who belived in the concept of “spontaneous generation”
Aristotle (384-322 BCE)
“Spontaneous Generation” was the idea that living matter originated spontaneously out of non-living matter.
spontaneous = unpalnned
A french scientist who carried out the expriement to disprove “spontenous generation”
Louis Pasteur (1822-1895)
Louis Pasteur is credited with conclusively disproving the theory of spontaneous generation with his famous swan-neck flask experiment. He subsequently proposed that “life only comes from life.”
The theory that suggested “life arose from nonliving matter”. It was a long-held belief dating back to Aristotle and the ancient Greeks.
spontaneous generation
Experimentation by Francesco Redi in the seventeenth century presented the first significant evidence refuting spontaneous generation by showing that flies must have access to meat for maggots to develop on the meat. Prominent scientists designed experiments and argued both in support of (John Needham) and against (Lazzaro Spallanzani) spontaneous generation. Louis Pasteur is credited with conclusively disproving the theory of spontaneous generation with his famous swan-neck flask experiment in 1860. He subsequently proposed that “life only comes from life.”
tiny organelles inside cells that generate almost all our energy in the form of ATP
mitochondria
باتری سلول
ساختارهایی در درون سلول که سازندۀ انرژی شیمیایی برای سلولها از جمله تک تک سلولهای ما هستند. و این انرژی تولید شده در ملکولی کوچکتر بنام آدنوسین تری فسفات ATP ذخیره میشوند و این ملکول نقش باتری را دارد.
Greek mitos “thread,” a word of uncertain etymology, + khondrion “little granule,” diminutive of khondros “granule, lump of salt”
“a region of space where the force of gravity is so strong that nothing, not even light, can travel fast enough to escape from its interior.”
Black hole
Black Holes: A Very Short Introduction (Very Short Introductions)
Katherine Blundell
a star that has exploded, strongly increasing its brightness for a few months
supernova
The day came when the fuel ran out completely. Gravity won the battle: the star imploded. After the millions of years of burning, the collapse took a split second. It prompted a rebound so explosive that it lit up the universe – a supernova.”
Excerpt From
A (Very) Short History of Life On Earth: 4.6 Billion Years in 12 Chapters
Henry Gee
The twisted shape of DNA
Double helix
DNA is made up of three different things: sugar, phosphate, and bases. These are joined together to make one really long chain that forms a shape called a double helix. DNA has a strong structure and can store information for a long time.
A complete set of your DNA
Genome
The genome is the entire set of DNA instructions found in a cell. In humans, the genome consists of 23 pairs of chromosomes located in the cell’s nucleus, as well as a small chromosome in the cell’s mitochondria. A genome contains all the information needed for an individual to develop and function.
the hypothetical common ancestor of all life on Earth, representing the point where all known species diverged and began their separate evolutionary paths.
LUCA
stands for “Last Universal Common Ancestor.”
While LUCA is not a specific individual organism, it’s a concept used in evolutionary biology and molecular biology to understand the common ancestry of all living organisms.
