Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > B15 Genetics and Evolutionn > Flashcards

B15 Genetics and Evolutionn Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

A large amount of our understadnings of genetics came from what monk ?

A

-Gregeor Mendel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What experiment did Gregor Mendel carry out ?

A
  • Mendel carried out thousands of breeding experiments on pea plants .
  • At this time , scientists did not understand how inheritance worked .
  • He looked at many different characteristcs 0 shape of the pod and colour of flowers .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How did scientists back in the day believe characteristics were inherited ?

A

-Many believed that characteristics were blended when they were inherited .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What did Mendel conclude from his experiments ?

A
  • That characteristics were not blended during ineritaince (the shape of a pea pod has no effect on the colu .
  • Mendel said characteristics were determined by units .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What were the units Mendel was talking about ?

A

These units do not change when passed onto descendants .

-These units are called genes .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What other conclusion did Mendle have from his experiment (2)

A
  • He showed some characteristics could be masked and hten reappear in later generations .
  • These are now knon as recessibe alelles .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why didn’t scienitsts believe mendel ?

A
  • Mendel published his research in a scientidic paper .
  • But many scientits still held onto the idea that chaacteristc were blended when inherited and his discovery was forgotten .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How did Mendel’s discovery be remembered again ?

A
  • In the 1800s , scienits looked at how chromosomes behaved in cell divion . Then scientists rediscovered Mendels work on geentics .
  • By 1900s , scientists realised that Mendel’s units behaved in a simialr way to chromosomes .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happened in 1900s

A

-This time thereofre , Mendel’s units renammed genes , and scientists realised genes must be lcoated on chromosomes .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happened in 1859 ?

A

-Darwin publishedhis theory in a book called the Origin of Species .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why was Darwin’s theory extremely controverisial ?

A

-In early Victorian ENgland , lots of people strongly believed that God made all animals and plants that lived on Earth . Darwin’s thoery challenged that belief .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why was Darwin’s theory extremely controverisial ? (2)

A

-At the time , a lot of people strongly believed that God made all animals and lants that lived on Earth . Darwin’s thoery challenged that idea .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why was Darwin’s theory extremely controverisial ?(3)

A

-At that time , many scientists felt that Darwin did not have enough evidence to back up his theory .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why was Darwin’s theory extremely controverisial ? (4)

A

-People did not understand how characteristics are inherited . (Genetics not understood until 50 years after Dawrin’s thoery was published)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What did Alfred Russel Wallace do ?

A
  • He travelled looking at different animals and plants .

- he was interested in warning colouraiton and wanted to know hwo warning colours evolved .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happened in 1858

A
  • Charles Darwin and Alfred Russel ahd the same findings about natural selecion and jointly published there findings .
  • Next year , Darwin published ‘on the origin of species’
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is speciation ?

A

-How new species form .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

-What did Wallace notice ?

A

He noticed that closely related species were often separated by geographical barriers such as a wide river .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What needs to happen for speciation to take place ?

A

-There has to be a geographical barrier which separtes the populations into two grougps ,which prevents interbreeding between the two populations .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q
  1. How species formed in depth
A

-A place containing one species of animals , all these animals interbreed , so any beneficial muation spreads thorugh the howle population .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  1. How species formed in depth
A
  • A geographical barrier (river) , separates that species of animals into two groups .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q
  1. How species formed in depth
A

As two populations are now separated , there is no interbreeding between the two groups .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q
  1. How species formed in depth
A
  • Overtime , natural selection , will favour different alleles in both groups (the food source may be different on one side compared to the other .)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
  1. How species formed in depth
A

As there is no interbreeding between the two populations , any mutations that occur cannot spread between the two populations .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
  1. How species formed in depth
A

This means over many generations , the two populations of that species will begin to change .

26
Q
  1. How species formed in depth
A

-If the geographical barrier goes away the two populations of that animal can mix .

27
Q
  1. How species formed in depth
A

-At this point the phenotypes of the two poulations are so different , they can no longer reproduce to make fertile offspring .

28
Q
  1. How species formed in depth
A

Now those two groups are two different species .

29
Q

What was Jean Baptiste Lamark’s theory ?

A
  • He noticed that animals seemed well sutied to their enviornment and suspected thorugh their lifetime they would improve themselves .
  • (e.g giraffe’s long neck was sue to it streching for food higher and higher .)
30
Q

What was Jean Baptiste Lamark’s theory (2) ?

A

-Lamark also thought these changes caused byt he animals struggle was passed onto the ext generation which hten continued the evolutionary process .

31
Q

What was the difference in Charles Darwin and Lamark’s ideas ?

A

-In Darwin’s idea , the traits of the parents were passed on without being modified by the life of the parent (state Lamark’s theory).

32
Q

What did Darwin realise on HMS Beagle ?

A

-That in any populaiton of a living organism , there already exists variation in any given characteristic .

33
Q

What did Darwin realise on HMS Beagle ? (2)

A
  • Reproduction always gives more offpspring than the neviornent can support .
  • The organisms that have inherited the characteristics most suited to their environment - the ‘fittest’ are more likely to survive and breed successfully .
34
Q

What did Darwin realise on HMS Beagle ? (3)

A
  • When they brred , they pass on the characteristics that have enbaled them to survive to the next genration .
  • He also proposed changes in a species happens very gradually .
35
Q

What are fossils ?

A

-Fossils are remains of organisms from millions of years ago which are found in rocks .

36
Q

-What is one way fossils form ?

A

-Fossils can form when parts of organisms have not been destroyed . Can happen whn the conditions needed for decay are absent . (temperature cold , lack of oxygen and water ).

37
Q

-What is another way that fossils form (2)

A
  • Fossils can be the preserved traces of organisms .

- Animals can leave footprints or burrows and plants can leave preserved psaxces were roots were .

38
Q

What is the problem with fossils ?

A
  • Many of the earliest forms of life were soft bodied organisms .
  • Soft bodied organisms evry rarley form ossils .
  • Many of the fossils that did form have been destroyed by chages in rock in the Earth’s crust .
39
Q

What is the meaning of soft bodied organisms ?

A

-Organisms that don’t have sheels or skeletons .

40
Q

Why can’t cientits be certain how life on Earth begain ?

A

-As there are very few fossils of the early forms of life .

41
Q

What is the meaning of extinction ?

A
  • Extinction is when there are no remaining individuals of that species stil alive .
  • Fossils can show huge numbers of species that have become extinct .
42
Q

What is one reason for extinction ?

A
  • Species can become extinct due to a catastrophic event .

- Asteroid colliding with Earth eventually lead to extinction of dinosaurs .

43
Q

What is another reason for extinction ? (2)

A

-Sometimes , as pecies can become extinct when the environemnt chnages e.g changing weather patterns .

44
Q

What is another reason for extinction ? (3)

A

-A new disease or new predator could kill all the individuals of a species and make it extinct .

45
Q

What is another reason for extinction ? (4)

A
  • A species can become extinct if a new or more successive species eveloves nd competes with it .
    e. g for food sources or scarceness of water.
46
Q

As more species were discovered , what did scientists realise ?

A

-Those species have characteristics in comon .

47
Q

In the 1700s , what did Carl Linnaeas do ?

A

-He bagan to classigy species into different catgeroies based on their structure and characteristics .

48
Q

What did Liinaes divide all lviging organisms into ?

A

1.He divided all living organisms into two kingdoms . These are the ANIMAL kingdom and the PLANT kingdom .
2. He then divided each kingdom into number of smaller catgeories .
Kingdom , Phylum , Class, Order , Family , Genus , Species (King phillip came over for good soup ).

49
Q

How is every organism named ?

A

-From their genus and their species

This is known as bionomial name .

50
Q

-What is the meaning of a bionomial name ?

A

-Two names

51
Q

-How do you work out the bionomial name ?

A

The one with the capital letter is the first name /Genus

52
Q

What is Linaeus’s classification based on ?

A

-Based on characteristics we can see (shape of body , number of toes ).

53
Q

What classification sytem do scientists use now ?

A

They use the three domain sytem :

  • Archae
  • True bacteria
  • Eukaryotic
54
Q

Explain Archae

A
  • Archae are primitive (early stage ) bacteria .

- They are found in extreme conditions such as hotsprings .

55
Q

Explain True bacteria

A

-Kind that live in human digestive systems .

56
Q

Explain Eukaryota

A

-Include animals , plants , fungi and protists .

57
Q

What are evolutionary trees ?

A

Scientists use them to show how clsely related organisms are to eachother .

58
Q

What do you need to make an evolutionary tree ?

A

-Need classification data on living organisms such as DNA .

59
Q

How do you do evolutionary trees for extinct animals .

What is the problem with this ?

A
  • Scientits have to use fossils .

- The fossil records of many species are incomplete .

60
Q

Look at the evolutionary tree on the page make three comments /

A
  • Species one and two are closely related to eachother .
  • Species three is more distantly related .
  • But species 1 , 2 and three all share a common ancestor .

Biology (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions