Universe and Evolution

Question 1

What is natural selection and its process?

Answer 1

Natural selection is a process where species give rise to new species that have characteristics that makes them better adapted for survival
VERA
Variation - more members of a species are produced than can survive. Those with the more favourable traits (adaptations) win the struggle for survival.
Exist - the best adapted members survive (exist) to
Reproduce - pass on the successful traits (survival of the ‘fittest’) over time the species has
Accumulated - the most favourable traits - a new species has arisen

Question 2

What is natural selection also known as?

Answer 2

Survival of the fittest as those with good genetics are the ones who survive and produce offspring that have their adaptations.

Question 3

Order of main geological timescale

Answer 3

archaeozoic, proterozoic, palaeozoic, mesozoic, cainozoic

Question 4

When did humans evolve?

Answer 4

Primates evolved in the Cainozoic era

Question 5

What are fossils?

Answer 5

evidence of past life, parts of organisms, footprints, burrows. Most organisms are broken down by bacteria after they die, if an organism is covered soon after it may not decay but rather fossilise.

Question 6

Why don’t all organisms fossilise? What is premineralisation?

Answer 6

This cannot occur as the organism cannot be decomposed or eaten if it were to become a fossil.
Only hard body parts (bone, teeth, shells) - > soft body parts will not fossilise but may leave behind trace evidence (e.g. imprints)
Premineralisation - pressure from covering layers of dirt/rock

Question 7

What did Lamarck believe?

Answer 7

Suggested that changes acquired by individuals during its life time could be passed onto its offspring e.g. if I were a body builder my offspring would have muscles
Also suggested that if a species didn’t use a certain feature it would shrink and gradually be lost.

Question 8

What did Charles Darwin do?

Answer 8

Developed the theory of evolution by natural selection.

Question 9

Name of Charles Darwin’s ship

Answer 9

HMS Beagle

Question 10

Where did Charles Darwin go?

Answer 10

South America, Galapogas Islands with lieutenant Robert
Himself to Australia, Brazilian jungles, the Andes Mountains, Argentine grasslands

Question 11

What did Charles Darwin notice?

Answer 11

13 different variations of finch occurred with what they ate as well as different tortoise shells in the Galapogas Islands
Darwin proposed that finches shared ancestral species which had migrated out to all islands from mainland and evolved + adapted to suit their different environments and eating habits

Question 12

What did Alfred Wallace do?

Answer 12

Darwin drafted his theory in 1841 but didn’t publish it. Alfred wrote a letter to Darwin agreeing with his theory and prompted Charles Darwin to publish his Origin of Species book.

Question 13

What is a homologous structure? Give an example

Answer 13

Body structures that perform a different function but have similar bone structures. E.g. Pentadactyl limb: humerus, parallel radius and ulna, joints - carpals, metacarpals (palm), phalanges (fingers)

Question 14

What is an analogous structure? Give an example

Answer 14

Similar features found in different species that evolved independently due to similar selection pressures e.g. dolphins and sharks.

Question 15

Why are antibiotics important?

Answer 15

Antibiotics are developed to prevent the spread of bacteria and kill it. They are significantly used in society when a bacteria is causing a severe amount of damage to their population.

Question 16

Why are antibiotics becoming less useful?

Answer 16

Antibiotics are important medicines, but they’re becoming less effective. Every year, scientists discover new types of bacteria that are not killed by antibiotics. Bacteria that can survive and grow in the presence of antibiotics are described as antibiotic-resistant.
The consistent use of antibiotics resulted in the resistance of antibiotics from bacteria as overuse meant that they got used to the effect and learnt to overcome them.

Question 17

Comparative embryology

Answer 17

Organisms that go through similar stages in embryonic development are closely related. During early stages humans and rabbits and other animals appear to be similar.

Question 18

Describe evolution on planet

Answer 18

The precambrian Earth (prior to Cambrian period, start of Palaeozoic) Was very different to the planet we live on today. Without the ozone layer life was restricted to water.
The oldest fossils are evidence of prokaryotic life. Prokaryotes are single-celled organisms that lack a true nucleus e.g. bacteria.
At some stages prokaryotes carried out photosynthesis producing oxygen. The oxygen reacted with some substances in the oceans initially and then gradually built off the atmosphere.
The first eukaryotic cell ( cells with the nucleus) appeared 1.8 billion years ago followed by first multicellular organisms which have more than one cell to grow larger and become Specialized for particular functions.
500 million years ago fish was a first vertebrates. Plants colonised land –-Moss
300 million years ago during devonian and carboniferous periods, plants developed into a variety of complex forms
350 million years ago seed producing plants appeared, gymnosperms dominant plants in permian triassic and Jurassic period.
135 million years ago, Cretaceous periods - dinosaurs and flowering plants (angiosperms).
Australia used to be covered in forest but dried over time you collect this 30 million years ago

Question 19

Oldest to youngest to live on land

Answer 19

amphibians -> reptiles -> dinosaurs -> birds or mammals

Question 20

What is a carbon imprint?

Answer 20

Black print left behind after the organism decomposes

Question 21

Why was Darwin’s book controversial at the time?

Answer 21

While many scientists defended Darwin, religious leaders and others immediately rejected his theory, not only because it directly contradicted the creation story in the biblical book of Genesis, but also because – on a broader level – it implied that life had developed due to natural processes rather than as the creation of a loving God.

Question 22

What did Charles Darwin’s observations determine?

Answer 22

By recognising that the beaks and species of the finches varied depending on the food available on their island, Darwin understood that animals could adapt to their environment in order to survive. The distinct variations in beaks, size, shape, claw size etc helped conclude that the finches must have evolved over time from the original mainland species to suit the conditions found on each individual Island in the Galapagos. Darwin proposed that the variations seen both within and between the same species arose by chance, variations which gave any individual comparative advantage made them more likely to survive and therefore reproduce out competing those with less advantageous traits.

Question 23

Why is genetic variation important?

Answer 23

higher chance of species survival

Question 24

What is a mutation?

Answer 24

A mutation is a change in an organism’s DNA, due to some kind of disruptive process.

Question 25

What is the term for an environmental factor that causes mutations?

Answer 25

mutagen

Question 26

Uranium and sunlight can cause mutations.

What category of mutagens do these belong to?

Answer 26

Ionising radiation

Question 27

Mutations can produce new variants in existing genes. Gene variants are also known as…

Answer 27

alleles

Question 28

Geocentric def and who began the model

Answer 28

Developed by Pythagoras believing that Earth was the centre of solar system

Question 29

Heliocentric def and who began the model

Answer 29

model produced by Copernicus stating that Sun was centre of our solar system

Question 30

What solar system are we in?

Answer 30

The Milky Way

Question 31

What is a star?

Answer 31

Stars are immense spherical masses of hydrogen gas undergoing a fusion reaction, producing helium and enormous amounts of light and heat energy.

Question 32

What is ‘apparent magnitude’?

Answer 32

relative brightness of stars viewed from Earth

Question 32

What is the magnitude scale?

Answer 32

In the magnitude scale, bright stars have lower numbers. Using this scale, a star that is one magnitude value lower than another star is about 2.5 times brighter. Astronomers have extended the magnitude scale at each end to include celestial objects brighter than magnitude 1 and dimmer than magnitude 6.

Question 33

Why do stars twinkle?

Answer 33

Stars appear to ‘twinkle’ in the night sky. This is because the light travelling from a star is distorted by the Earth’s atmosphere. The light is bent in all directions as it passes through the moving air of the atmosphere. This causes the image to change slightly in brightness and position and hence twinkle. This is one of the reasons the Hubble telescope in orbit high above the Earth is so successful at capturing clear images of celestial objects. In space, there is no atmosphere to make the stars twinkle, allowing a much clearer image to be obtained.

Question 34

What is a constellation?

Answer 34

When viewed from Earth, the individual stars in a constellation may appear to be very close to each other. However, they can be separated by huge distances in space and in fact have no real connection to each other at all.
The constellations visible on any given night depend on the time of year. For example, Gemini and Leo are clearly visible in March but not in October.
Constellations are essentially a combination of stars that are close together viewed from Earth, astronomers of ancient civilisations grouped these stars according to the patterns or shapes they seemed to form.

Question 35

What is a nebula?

Answer 35

Stars are ‘born’ within nebulae from gas and dust coming together through the force of gravity. During this process, the centre of the nebula may heat up and glow. Eventually sufficient hydrogen gas may accumulate to form young stars.

Question 36

What is a main sequence star?

Answer 36

Stars then spend most of their life as stable ‘main sequence’ stars, and are powered by a fusion reaction within their core which converts hydrogen to helium. The size of a star determines how quickly the hydrogen in the core is used up. Our Sun is currently at this stage.

Question 37

How do stars become red giants?

Answer 37

Main sequence -> red giants
As helium builds up in the core of the star, the remaining hydrogen forms a shell around the core. The shell gradually expands and the star swells to 200 or 300 times its original size, cooling as it does so, to become a red giant.

Question 38

What is a red giant?

Answer 38

In the core of a red giant, new fusion processes take place, turning helium into heavier elements such as beryllium, neon and oxygen. This increases the rate of energy production and raises the star’s temperature. A sun-like star which has become a red giant might shine 100 times more brightly than it did in its stable period.
Eventually red giants collapse inwards leading to the destruction of the star. The nature of its death depends on the size of the original star.

Question 39

What are white dwarfs?

Answer 39

For stars less than about eight times the mass of our sun, the destruction of a red giant begins when the outer layers are thrown off into space and the core flares brightly, forming a ring of expanding gas called a planetary nebula.
It then slowly cools, becomes a cold black dwarf and disappears from view.

Question 40

How do stars die?

Answer 40

They swell into much larger red giants called super giants, then blow up in a huge explosion called a supernova.
The matter making up the star is hurled into space along with huge amounts of energy.
They produce heavy elements such as iron and lead.

Question 41

What is a light year?

Answer 41

A light-year is the distance that light travels in one year.

Question 42

What is a spiral galaxy and its subunits?

Answer 42

Spiral galaxies, like the Milky Way and Andromeda galaxies, rotate. They have a bright bulging middle with two or more curved arms of stars spiralling out from the centre. The middle parts of spiral galaxies spin faster than the edges. The older red stars are found closer to the centre and the younger blue stars are located on the outer arms of the spiral.
They can be divided into both:
Regular S
Barred SB
Which is subdivided by how tight the arms are
Sa, Sb, Sc
barred are also subdivided
SBa, SBb, SBc

Question 43

What are elliptical galaxies?

Answer 43

Elliptical galaxies are typically found in galaxy clusters.
They have an ellipsoid shape, though it can vary from almost a perfect sphere to an elongated oval.
The stars in an elliptical galaxy are old, some of the oldest in the universe.
The orbit of the stars is random and elongated, affecting the shape of the galaxy.
In general, the stars in elliptical galaxies are old, red stars. These galaxies look the same from all angles, too. Astronomers used the ages of the red stars in the elliptical galaxies to determine that these galaxies are pretty old.
They can be classified by their spherical-ness
Classified E0, E3, E7
E0 is most spherical, E7 is most elongated

Question 44

What is an irregular galaxy?

Answer 44

Irregular galaxies have no definite shape and tend to have very hot, new stars mixed in with lots of dust and gas.
Having a lot of gas and dust means that these galaxies have a lot of star formation going on within them. This can make them very bright.
They don’t show obvious spiral structure, nor do they show a central bulge, so they are not spiral galaxies. In addition, they lack symmetry, so are not elliptical galaxies.
Astronomers have measured the age of irregular galaxies and their ages are older than spirals, but younger than ellipticals. They are like teenage galaxies. Irregular galaxies are often formed by two regular galaxies that collide.

Question 45

Name planets in order in our solar system

Answer 45

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

Question 46

Which planets are gas planets and which are terrestrial in our solar system?

Answer 46

Mercury, Venus, Earth and Mars are terrestrial, the rest are gas

Question 47

What is AU?

Answer 47

Astronomical units -> distance between Earth and the Sun.
If you are trying to find the distance between Mercury and the sun in AU you would do distance in m between Mercury and Sun divided by AU in metres which is 149 000 000 000

Question 48

What is the local group?

Answer 48

is a collection of more than 30 galaxies within approximately 4 million light years of the Milky Way and gravitationally bound together. Two spiral galaxies, the Milky Way and Andromeda, are the two largest members of the Local Group. which also includes many dwarf galaxies such as the Magellanic clouds.

Question 49

What does “observable universe” mean?

Answer 49

The observable universe is everything that we’ve been able to see or observe thus far. Region of space visible to us from Earth

Question 50

Who developed the first telescope?

Answer 50

Galileo constructed and used one of the first telescopes in the early 1600s and with it described the crater-surfaced moon. He also discovered the moons of Jupiter which compelled him to reject the well accepted geocentric model of the universe.

Question 51

Why are observatories are generally located at high altitude on mountain ranges?

Answer 51

Observatories are generally located at high altitude on mountain ranges to minimise the distortion of images resulting from light passing through the atmosphere, and generally far from urban centres to escape light pollution.

Question 52

Why are telescopes placed outside the atmosphere?

Answer 52

to get around the Earth’s atmosphere so that we can get a clearer view of the planets, stars, and galaxies that we are studying. Space telescopes have the advantage of being above the blurring effects of the Earth’s atmosphere. In addition, there are many wavelengths from the electromagnetic spectrum that do not reach Earth because they are absorbed or reflected by the Earth’s atmosphere.
Visible light and radio waves are the only two frequencies within the electromagnetic spectrum that penetrate the Earth’s atmosphere to any large extent, allowing us to place optical and radio telescopes on the ground. The remaining types of radiation are filtered out by the atmosphere. Ultraviolet light for example is absorbed by ozone in the atmosphere. So, to place X-ray or infra-red telescopes on the ground would be fruitless.

Question 53

How do astronomers detect celestial objects that do not produce light?

Answer 53

The use of spectrum. Many celestial objects do not emit radiation in the visible range and so would be invisible if it were not for the development of telescopes that detect other frequencies of electromagnetic radiation. e.g. astronomers can locate black holes by detecting X-rays emitted by material in the immediate environment of the black hole.
Ultraviolet light reveals hot stars and quasars while visible light allows us to image hot stars, planets, nebulae and galaxies. In the infra-red we see cool stars, regions of star birth and cool dusty regions of space. Radio waves are unimpeded by the dust in our galaxy so they can be used to detect other galaxies unable to be seen by optical telescopes behind the centre of our galaxy.
Gamma rays and xrays are for violent events around a black hole.
Microwaves are for beginning or origin of the universe.

Question 54

What was the Hubble telescope?

Answer 54

It was launched April 24th 1990, it determined the existence of blackholes within many galaxies, and that there is mysterious dark matter that makes up most of the universe’s mass and structure.

Question 55

What is the JWST?

Answer 55

The James Webb Space Telescope was launched 25 December 2021 to replace the Hubble as a bigger, better and more efficient telescope having longer wavelength coverage and greatly improved sensitivity.

Question 56

Describe the Big Bang

Answer 56

hot and infinitely dense point exploded which converted some of this energy to the simplest form of matter - particles such as quarks which are the building blocks of protons and neutrons.
Over time, the universe expanded and cooled and more complex matter, such as hydrogen atoms, was formed. Stars formed from the gravitational attraction of hydrogen leading to the development of the complex universe we observe today. Matter appeared -> Protons and neutrons formed -> Atoms first existed -> Galaxies began to form

Question 57

What are epochs?

Answer 57

Epochs are the different eras that the universe went through to develop
Strong nuclear broke away -> universe expanded rapidly -> cooled etc

Question 58

State 3 points of evidence of the big bang theory

Answer 58

1. galaxies are moving further apart, leading scientists to conclude that the galaxies were once closer together before some kind of explosion.
2. It explains the abundance of hydrogen, helium and other elements in the universe.
3. Astronomers have observed the cosmic background radiation throughout the universe, the afterglow of the big bang explosion.

Question 59

What is the Doppler Effect?

Answer 59

Christian Johann Doppler was an Austrian physicist who noted the change in pitch that results from a source of sound approaching or moving away. Doppler suggested that this changing pitch in sound waves might be seen in light as well. He predicted that the Doppler effect would produce a change in the frequency of light waves emitted from a moving source. Higher frequency towards you, lower frequency when it’s going by

Question 60

What is Hubble’s Law?

Answer 60

Edwin Hubble predicted that nearly all galaxies were moving away from ours and that the furthest are moving the fastest
This law states that the further away a galaxy is, the greater is its red shift and so the faster it is moving away from us.

Question 61

What is the red shift?

Answer 61

• provides evidence of the expanding universe
  Results of a stars movement away from Earth as it is getting darker hence red, if it were coming towards us it would be a blue shift because it is becoming brighter.

Question 62

What is luminosity?

Answer 62

a measure of the total amount of energy radiated by a star or other celestial object per second