Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Bio 20 > Chapter 4 > Flashcards

Chapter 4 Flashcards

1
Q

How does Sexual Reproduction work

A

Allows for genetic information from two parents to be shared in their offspring (exactly 50% mother and 50% father)

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

Define mutations

A

Change in genetic information caused by a problem in DNA replication or because of an environmental factor

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

Define mutagens and give 3 examples

A

Substances that cause mutations

  1. Cigarettes
  2. Radiation
  3. UV light
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the two types of mutations

A

Disadvantageous mutations
Advantageous mutations

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

Define Disadvantageous mutations and give an example

A

Mutations that decrease an individual’s ability to reproduce because they may affect survival

Sickle-cell anemia - a genetic disease in which blood cells mutate to look like a sickle which can cause anemia

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

Define Advantageous mutations and give 3 examples

A

Mutations that give an individual an advantage to reproduce over an individual who doesn’t have the mutation

  1. Horseflies resistant to DDT
  2. California ground squirrels that can combat snake venom
  3. Certain humans who are resistant to HIV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define selective pressure and give 4 examples

A

Environmental conditions that select for certain characteristics of individuals and select against others

  1. Drought
  2. Famine
  3. Weather
  4. Competition for food, space, and mates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the two ways in which variation occurs

A

Sexual reproduction
Mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define natural selection

A

A process that results when the characteristics of a population of organisms change because individuals with certain inherited traits survive specific local environmental conditions and through reproduction, pass on their traits to their offspring.

Those who pass on their traits are said to have the highest fitness.

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

Give an example of natural selection and describe it

A

Peppered moths:

The environment determines who lives and who dies. In a dark environment black peppered moths will live and white ones will get eaten while in a light environment white peppered moths will live and the black ones will get eaten.

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

What are the 3 human impacts on natural selection and give an example for each

A

Loss of genetic diversity - farmers practicing monoculture
Artificial selection - super-bull
overuse of antibiotics - leads to antibiotic-resistant bacteria

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

Explain adaptation

A

Organisms must adapt to their changing environment or they will die

Adaptations are a result of gradual changes in members of a population over time

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

What are the 3 types of adaptations

A

Structural adaptations
Behavioural adaptations
Physiological adaptations

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

Define structural adaptations

A

Physical features of an organism

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

Define behavioural adaptations

A

Inherited behaviour and/or learned behaviour of an organism

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

Define physiological adaptations

A

Internal features that permit the organism to perform special functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define heritable

A

Can pass on to offspring

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

Define speciation and give an example

A

The formation of a new species

Ex. Darwin’s finches

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

Define adaptive radiation

A

The diversification of a group of organisms into forms filling different ecological niches

ie. when a species develops into a few different species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Define niche

A

A position or role taken by a kind of organism in it’s community

21
Q

Under what circumstance does speciation occur

A

Only occurs if organisms are reproductively isolated from each other. If they can’t mate, then over time a new species will form.

22
Q

What are the two causes of speciation

A

Geographical Barriers
Biological Barriers

23
Q

What are the two types of biological barriers:

A

Pre-zygotic and post-zygotic

24
Q

Define pre-zygotic barrier

A

Something that prevents mating or fertilization if mating occurs

25
Define post-zygotic barrier
Prevent hybrid offspring from developing into a viable, fertile adult
26
What proves how continents are moving apart and there used to be a supercontinent called Pangea
Certain fossils and animals can be found on separate continents and therefore must have been in close proximity with each other at some point
27
Explain chronometric dating
Uses radioisotopes to produce dates for when a specimen is formed
28
Define half-life
How long does it take for 50% of radioactive substance to decay into a different element
29
How does carbon dating work
Can use the different types of carbon to date different sources
30
What is the order number of fossil records
First - amphibians Next - reptiles Last - mammals and birds
31
Define transitional fossils
Fossils that show links between groups of organisms
32
Define homologous structures
Organisms Have similar structural elements and origin but may have different functions
33
Define analogous structures
Body parts that perform similar functions even though organisms do not have common evolutionary origin
34
Define vestigial structures
Have no apparent function, but resemble structures their ancestors possessed
35
How can we trace human ancestry and where can we trace it too
mitochondrial DNA is inherited from your mother because the egg is much larger than the sperm and this can be traced to Africa
36
How do we compare the DNA of animals
Find the letters that are exactly the same on the same row and count the bases (most DNA bases are similar)
37
Define hybrid
Mixed animal that’s viable
38
Define viable
Alive
39
Define fertile
Can produce offspring
40
Define transformation and give an example
New species gradually develops and replaced the old species as a result of mutation and adaption to changing environmental conditions The mammoth
41
Define divergence
One or more species arise from a parent species that continues to exist
42
Define gradualism
Gradual accumulation of small changes over a long time
43
Define punctuated equilibrium
Rapid bursts of change mixed with long periods of little to no change
44
Most evolution happens (slow/fast) but the one exception is with _______ that happen (slow/fast)
Slow, plants, fast
45
What are the two types of evolution
Divergent and convergent
46
Define divergent evolution
When two species share the same ancestral origins but have evolved differently
47
Define convergent evolution
Process whereby organisms not closely related independently evolve similar traits as a result of having to adapt to similar environments or ecological niches
48
Define extinction
The end of an organism or group of organisms (usually a species)

Bio 20 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions