Brainscape's Knowledge GenomeTM

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


See full index

BIO EXAM 1 > BIO EXAM 1 > Flashcards

BIO EXAM 1 Flashcards

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

What is evolution?

A

The process by which different organisms change, adapt, or diversify their genetic composition over successive generations

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

How do scientists determine whether evolution is occurring in a population?

A

By tracking allelic frequencies in populations and if said populations are not in Hardy-Weinberg equilibrium

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

What is the Hardy-Weinberg equilibrium?

A

A theorem that explains why a population is not comprised of a dominant genotype.
It states that when a population is in equilibrium, the genotypic frequencies will remain proportionally balanced.

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

What are the requirements for H-W equilibrium?

A

1) No selection
2) No mutation
3) No migration
4) Small population
5) Random mating

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

What are the 3 kinds of selection?

A

1) Disruptive selection- two extremes are favoured. Ex. birds’ beaks sizes
2) Directional selection- One extreme is favoured. Ex. Industrial melanic moths in popullted areas
3) Stabilizing selection- Intermediete traits are favoured. Ex. Average human baby weight

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

What mechanics contribute to evolution?

A

1) Mutation
2) Gene Flow
3) Natural selection
4) Nonrandom mating
5) Genetic Drift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Natural Selection

A

THe process by which organisms that are best equipped to survive in their environment, get to reproduce.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Niche

A

The role an organism plays in a community

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

Gene Flow

A

Movement of alleles between populations, usually with migration

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

Genetic Drift

A

Random fluctuation in allele frequencies by chance. I.e. natural disaster

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

Adaptation

A

The process by which a species or population becomes better suited to its environment

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

Reinforcement

A

In speciation, the process by which partial reproductive isolation is increased by selection against mating between members of the two populations, eventually resulting in complete reproductive isolation

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

Adaptive Radiation

A

One species rapidly evolves to fill multiple niches

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

Convergent Evolution

A

Process whereby distantly related organisms independently evolve similar traits

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

Sympatric Speciation

A

The differentiation of populations within a common geographic area into species

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

Subspecies

A

A geographically defined population or group of populations within a single species that has distinctive characteristics

17
Q

Allopatric Speciation

A

The differentiation of geographically isolated populations into distinct species

18
Q

Reproductive Isolation

A

Any barrier that prevents genetic exchange between species
PREZYGOTIC:
1) Ecological isolation
2) Behavioral isolation
3) Temporal isolation
4) Mechanical isolation
5) Prevention of gamete fusion

POSTZYGOTIC:
1) Hybrid inviability or infertility

19
Q

Biological Species Concept

A

The concept that defines species as groups of populations that can breed and produce fit offspring- is reproductively isolated

20
Q

Ecological Species Concept

A

The distinction among species is maintained by natural selection (each species has adapted to its own specific part of the environment)

21
Q

Phylogenic Species Concept

A

Species are defined by examining their evolutionary history in populations

22
Q

Artificial Selection

A

Selective breeding of desirable traits that get to reproduce as chosen by humans

23
Q

What is a fossil?

A

A preserved remains of a once-living organism

24
Q

3 Conditions for a fossilization to occur

A

1) Organisms must be buried in sediment
2) The calcium in bone or other tissue must mineralize
3) Surrounding sediment must harden to form rock

25
Q

What is a transition fossil?

A

A fossil that exhibits both traits from ancestral and present-day organisms

26
Q

Examples of two transition fossils

A

Archaeopteryx- Traits of modern-day birds (feathers) and ancient dinosaurs (Teeth, bony tail, and carnivorous features)

Pakicetus- Traits of modern-day whale (skull) but land-dwelling and four limbs

27
Q

Central dogma

A

DNA → mRNA → protein; only flows in one direction

28
Q

How does natural selection promote speciation?

A

It increases reproductive isolation as different species select for different adaptations and works against the fitness of hybrids

29
Q

How does gene flow work against speciation?

A

With incompletely isolated populations, gene flow is an intermediate for genotypes and the two populations lose their genetic distinctiveness/erase their differences

30
Q

Extinction

A

The process for species or populations to die off

31
Q

How does extinction occur?

A

When species die off because of environmental forces, overexploitation, or evolutionary changes

32
Q

How does molecular evidence support the theory of evolution?

A
33
Q

Pleiotropy

A

When one gene codes for more than one traits

BIO EXAM 1 (2 decks)

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