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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)

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2
Q

Define mutations

A

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

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3
Q

Define mutagens and give 3 examples

A

Substances that cause mutations

  1. Cigarettes
  2. Radiation
  3. UV light
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4
Q

What are the two types of mutations

A

Disadvantageous mutations
Advantageous mutations

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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

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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
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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
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8
Q

What are the two ways in which variation occurs

A

Sexual reproduction
Mutations

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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.

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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.

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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

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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

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13
Q

What are the 3 types of adaptations

A

Structural adaptations
Behavioural adaptations
Physiological adaptations

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14
Q

Define structural adaptations

A

Physical features of an organism

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15
Q

Define behavioural adaptations

A

Inherited behaviour and/or learned behaviour of an organism

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16
Q

Define physiological adaptations

A

Internal features that permit the organism to perform special functions

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17
Q

Define heritable

A

Can pass on to offspring

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18
Q

Define speciation and give an example

A

The formation of a new species

Ex. Darwin’s finches

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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

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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
Q

Define post-zygotic barrier

A

Prevent hybrid offspring from developing into a viable, fertile adult

26
Q

What proves how continents are moving apart and there used to be a supercontinent called Pangea

A

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
Q

Explain chronometric dating

A

Uses radioisotopes to produce dates for when a specimen is formed

28
Q

Define half-life

A

How long does it take for 50% of radioactive substance to decay into a different element

29
Q

How does carbon dating work

A

Can use the different types of carbon to date different sources

30
Q

What is the order number of fossil records

A

First - amphibians
Next - reptiles
Last - mammals and birds

31
Q

Define transitional fossils

A

Fossils that show links between groups of organisms

32
Q

Define homologous structures

A

Organisms Have similar structural elements and origin but may have different functions

33
Q

Define analogous structures

A

Body parts that perform similar functions even though organisms do not have common evolutionary origin

34
Q

Define vestigial structures

A

Have no apparent function, but resemble structures their ancestors possessed

35
Q

How can we trace human ancestry and where can we trace it too

A

mitochondrial DNA is inherited from your mother because the egg is much larger than the sperm and this can be traced to Africa

36
Q

How do we compare the DNA of animals

A

Find the letters that are exactly the same on the same row and count the bases (most DNA bases are similar)

37
Q

Define hybrid

A

Mixed animal that’s viable

38
Q

Define viable

A

Alive

39
Q

Define fertile

A

Can produce offspring

40
Q

Define transformation and give an example

A

New species gradually develops and replaced the old species as a result of mutation and adaption to changing environmental conditions

The mammoth

41
Q

Define divergence

A

One or more species arise from a parent species that continues to exist

42
Q

Define gradualism

A

Gradual accumulation of small changes over a long time

43
Q

Define punctuated equilibrium

A

Rapid bursts of change mixed with long periods of little to no change

44
Q

Most evolution happens (slow/fast) but the one exception is with _______ that happen (slow/fast)

A

Slow, plants, fast

45
Q

What are the two types of evolution

A

Divergent and convergent

46
Q

Define divergent evolution

A

When two species share the same ancestral origins but have evolved differently

47
Q

Define convergent evolution

A

Process whereby organisms not closely related independently evolve similar traits as a result of having to adapt to similar environments or ecological niches

48
Q

Define extinction

A

The end of an organism or group of organisms (usually a species)

Bio 20 (15 decks)

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