B15 - Genetics and Evolution Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

How did Chalres Darwin gain evidence for his theory

A
  • He travelled around the world in the 1800s
  • HE collected fossils and saw they were similar to organisms alive today
  • Did many years of experimentation and discussion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Ideas of the theory of evolution by natural selection

A
  • Within a species, there is a wide range of genetic variation for any characteristic
  • Individuals wwith charcteristics most suited to their environment are more likely to survive and breed successfully
  • The characteristics than have enabled these individuals to survive are then passed onto the next generation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why was Darwin’s Theory controversial and only gradually accepted?

A
  • Lots of people strongly believed that God made all living things on earth
  • They believed God did this in 7 days (creationism)
  • Many scientists felt that there wasn’t enough evidence to back up the theory
  • Genetics and inheritance were not understood until 50 years later
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Alfred Russel Wallace best known for

A
  • His work on warning colouration in animals
  • His theory of speciation
  • He also independently proposed the theory of evolution and in 1858, him and Darwin published joint writings on their findings
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What did Jean-Baptiste Lamarck’s theory suggest and is it correct today

A
  • When a characteristic is regularly used, it becomes more developed
  • This strengthened characteristic is the passed onto the offspring
  • However, we know today that this theory is incorrect in the vast majority of cases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does the process of speciation form new species (common 6 marker)

A
  • The populations are isolated (separated) perhaps due to a geographical barrier - this stops interbreeding between the different populations
  • There are differences in the environments that the different populations live in - different biotic and abiotic factors
  • This causes different mutations between the populations allowing them to survive in their habitat better but these mutations cannot spread to the other populations
  • Beneficial alleles passed onto offspring by reproduction
  • Alleic frequency increases
  • If the different populations are allowed to mic again, their phenotypes are so different that they cannot interbreed to produce fertile offspring
  • This means different species have been formed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What did Gregor Mendel do and what did he discover

A
  • He did thousands of breeding experiments on pea plants
  • He realised that characteristics are not blended during inheritance (blending was a preconceived idea
  • He stated that characteristics are determined by inherited units and these units don’t change when passed onto the offpsring
  • He also showe that some charcterisitcs could be ‘masked’ and then reappear in later generations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why was Mendel’s work accepted

A
  • By the 1900s scientists working on cell division realised Mendel’s ‘units’ behaved in similar ways to chromosomes
  • The units were then renamed to genes and scientists realised that genes were located on chromosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are fossils

A
  • The remains of organisms from millions of years ago found in rocks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

3 ways that fossils are formed

A
  • Parts of the organism don’t decay due to lack of necessary conditions for decay
  • When the decaying parts of the organism are replaced by minerals and rock
  • The preserved traces of organisms e.g. footprints
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Main way that fossils are formed

A
  • Animal dies and overtime is buried by sediment and rock
  • The soft parts of the animal decays
  • The hard bones dont decay but they are replaced by minerals that form the same shape as the bones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why is the fossil record incomplete/why is it hard to find fossils of early organisms

A
  • Many of the early organisms were soft-bodied so didn’t form fossils
  • Many of the fossils that did form were destroyed by geological activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is extinction

A

The permanent loss of all the individuals in a species

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

Why may species become extinct

A
  • New disease
  • New predator
  • Environmental changes
  • Evolution of a more successful species that leads to increased competition for resources
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does antibiotic resistance happem

A
  • There may be a mutation which makes one bacterium resistance to an antibiotic
  • If the antbiotic is used, all of the other bacteria are killed leaving only the resistant bacterium
  • The antibiotic resistance strain can reproduce without any competition from other bacteria increasing the population size
  • This spreads rapidly as people are not immune to it and there is no effective treatment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How to prevent antibiotic resistance

A
  • Not prescribing antibiotics in inappropriate situations e.g. for a viral infection
  • Patients making sure they complete their course of antibiotics
  • Restrict the use of antibiotics in farming
16
Q

Order of the Linnean classification system

A

Kingdom
Phylum
Class
Order
Family
Genus
Species

17
Q

What is the binomial name of an organism

A

Its genus and species

18
Q

What classification system did Carl Woese develop

A

The three domain system
* One domain is archae
* Another is true bacteria
* The last is eukaryota

19
Q

What is a species

A

A group of organisms that can interbreed to produce fertile offspring