Brainscape's Knowledge GenomeTM

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


See full index

Biology 1M03 > Lecture 1-5 > Flashcards

Lecture 1-5 Flashcards

1
Q

Cell Theory

A

Proposed that all organisms are made of cells and that all cells come from preexisting cells. 1) Crude microscope in 1665 by Robert Hooke 2) Anton van Leeuwenhoek used a 300X magnification telescope to look at the structure of human blood and sperm cells. 3) By the early 1800’s there was enough data for cell theory.

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

Theory of Evolution by Natural Selection

A

Maintains that species have changed through time and that all species are related to one another through common ancestry.

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

Components of scientific theories?

A
  • describes a pattern

- identifies a mechanism or process that is responsible for creating that pattern

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

Darwin and Wallace -

A
  • Species are related by common ancestry

- Characteristics of species can be modified from generation to generation

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

Evolution

A

-Are related to one another and can change through time whenever two conditions are met: 1) vary in characteristics that are heritable. 2) certain versions of these heritable characteristics help individuals survive better.

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

Difference between Evolution and Natural Selection

A

Natural selection acts on individuals but evolutionary change affects only populations.

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

Fitness

A

The ability of an individual to produce offspring

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

Adaptation

A

A trait that increases the fitness of an individual in a particular environment

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

Two Unifying Ideas in Biology

A
  • The cell is the fundamental structural unit in all organisms
  • All species are related by common ancestry and have changed over time in response to natural selection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Speciation

A

Natural selection has caused populations of one species to diverge and form new species.

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

Taxonomy

A

The effort to name and classify organisms:

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

Genus

A

-a closely related group of species

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

Species

A
  • is made up of individuals that regularly breed together or have characteristics that are distinct from those of other species.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Taxonomic Levels

A

Kingdom, Phylum, Class, Order, Family, Genus. Species

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

Five Kingdoms

A
  • Kingdom Monera
  • Kingdom Protista
  • Kingdom Plantae
  • Kingdom Fungi
  • Kingdom Animalia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Phylogeny

A

The actual genealogical relationships between all individuals.

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

rRNA sequences in closely related organisms

A

more similar than in less closely related organisms

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

Null Hypothesis

A

What we should observe when the hypothesis being tested doesn’t hold true.

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

Hypothesis

A

Make testable predictions that can be supported or rejected by collecting and analyzing data.

  • control groups
  • conditions must be carefully controlled
  • Repeating the test is essential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

topological thinking

A
  • Aristotle

- ladder of life: based on size and complexity of species with humans at the top

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Lamarck

A

First to propose a formal theory of evolution, turned the ladder of life into an escalator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Decent with Modification

A

species existing today have descended from other, preexisting species are modified, or change through time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Evidence that Species aren’t static

A

-Fossils and the fossil record

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Transitional Forms

A
  • a fossil species with traits that are intermediate between those of older and younger species.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Law of Succession

A

Extinct species in the fossil record were succeeded in the same region by similar species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Vestigial Traits

A
  • a reduced or incompletely developed structure that has no function or reduced function, but is clearly similar to functioning organs or structures in closely related species. (Proof against special creation)
27
Q

Homology

A

A similarity that exists in species descended from a common ancestor.

28
Q

Genetic Homology

A

Similarity in the DNA sequences

29
Q

Developmental Homology

A

A similarity in embryonic traits.

- often observed in the overall morphology of embryos and tin the fate of particular embryonic tissues.

30
Q

Structural Homology

A

Similarities in adult morphology.

- Traits are similar in different species because the species in question are related to each other.

31
Q

Four Steps in Evolution by Natural Selection

A

1) individual organisms that make up a population vary in the traits they possess, ex such as size and shape.
2) Some of the trait differences are heritable, meaning they are passed on to offspring genetically
3) Only some individuals in the population survive long enough to produce offspring and some produce more than others.
4) Individuals with certain heritable traits are more likely to survive and reproduce.
Variation among individuals is essential if evolution is to occur

32
Q

Acclimation

A

-Changes in an individuals phenotype that occur in response to changes in environmental conditions - NOT PASSED ON TO OFFSPRING

33
Q

The Nature of Natural Selection

A
  • There is no such thing as a higher or lower organism
  • Natural selection is not goal directed or progressive
  • Individuals with self-sacrificing alleles die and do not produce offspring, but individuals with selfish, cheater alleles survive and produce offspring.
  • Not all traits are adaptive
34
Q

Genetic constraints

A
  • Genetic correlation: in which selection of one trait causes a change in another trait as well.
  • Lack of genetic variations
  • Fitness Trade-off
  • Evolution: change in allele frequencies
35
Q

Fitness Trade-off

A
  • a compromise between traits in terms of how those traits perform in the environment.
36
Q

Genetic Correlation

A

A type of evolutionary constraint in which selection on one trait causes a change in another trait as well.

37
Q

Population

A

A group of individuals from the same species that live in the same area at the same time, and regularly interbreed

38
Q

Four Mechanisms that Shift Allele Frequencies in Populations. . .

A
  • Natural Selection
  • Genetic Drift
  • Gene Flow
  • Mutation
  • Natural Selection is the only mechanism that can result in adaptation on its own *
39
Q

Natural Selection

A

Increases the frequency of certain alleles - the ones that contribute to success in survival and reproduction.

40
Q

Genetic Drift

A

Causes allele frequencies to change randomly. In some cases, drift may even cause deleterious alleles to increase in frequency.

41
Q

Gene Flow

A

Occurs when individuals leave one population, join another and breed. Allele frequencies may change when gene flow occurs, because arriving individuals introduce alleles to their new population and departing individuals remove alleles from their old population.

42
Q

Mutation

A

Modifies allele frequencies by continually introducing new alleles. The alleles created by mutation may be beneficial or detrimental or have no effect on fitness

43
Q

Gene Pool

A

All of the gametes produced in each generation, The gene pool is combined at random to form offspring.

44
Q

Hardy-Weinberg Principle Assumptions

A
  • No natural selection at the gene in question
  • No genetic drift or random allele frequency changes
  • No gene flow
  • No mutation
  • Random mating with respect to the gene pool in question.
45
Q

Balancing Selection

A
  • heterozygous individuals have higher fitness than homozygous individuals do.
  • This helps maintain genetic variation
46
Q

Genetic Variation

A
  • Refers to the number and relative frequency of alleles that present in a particular population.
  • Genetic variation is very important because if genetic variation is low and the the environment changes it’s unlikely that any allele will be present that have high fitness under the new conditions.
47
Q

Directional Selection

A

When the average phenotype of the populations changes in one direction

  • tends to reduce the genetic diversity of populations
  • alleles with a frequency of 0.0 are said to be lost and those with a frequency of 1.0 are said to be fixed.
48
Q

Purifying Selection

A

Occurs when disadvantageous alleles decline in frequency

49
Q

Stabilizing Selection

A

When selection reduces both extremes in a population

  • there is no change in the average value of a trait over time
  • genetic variation in the population is reduced
50
Q

Disruptive Selection

A

Has the opposite effect of stabilizing selection. Instead of favoring phenotype near the average value and eliminating extreme phenotypes, it eliminates phenotypes near the average value and favors extreme phenotypes.
- sometimes plays a part in speciation

51
Q

Speciation

A

The formation of the new species

52
Q

Genetic Drift

A

A change in allele frequency in a population that is due to chance. It causes allele frequencies to drift up and down randomly overtime.

  • Most pronounced in small populations
  • can lead to the random loss or fixation of alleles
53
Q

Sampling error

A

When drift occurs and allele frequencies change due to blind luck

54
Q

Genetic Marker

A

A specific allele that causes a distinctive phenotype

55
Q

Founder Effect

A

A change in allele frequencies that occurs when a new population is established.

  • Once breeding took place drift continued to act via sampling errors that occurred during fertilization
  • Each time a founder event occurs a founder effect is likely to accompany it changing allele frequencies via genetic drift.
56
Q

Genetic Bottleneck

A
  • a sudden reduction in the number of alleles in a population.
57
Q

Gene Flow

A

The movement of alleles from one population to another, It occurs when individuals leave one population, join another and breed.

  • It usually equalizes allele frequency between source population and the recipient population.
  • Gene flow is random with respect to fitness *(Can increase or decrease average fitness in a specific population, but with regards to population, it equalizes and reduces genetic differences.
58
Q

Mutation

A
  • Restores genetic diversity over time.
  • It is random with respect to the fitness of the affected allele,
  • If mutation did not occur evolution would eventually stop (Ultimate source of genetic variation)
59
Q

Deleterious Alleles

A

Alleles that lower fitness

60
Q

When do mutations occur?

A

When DNA polymerase makes an error as it copies a DNA molecule, resulting in a change of the deoxyribonucleotides. If a mutation occurs in a stretch of DNA that codes for a protein, the changed codon may result in a polypeptide with a novel amino acid sequence.

61
Q

Inbreeding

A
  • Mating between relatives
  • does not cause evolution, because allele frequencies do not change in the population as a whole. Changes genotype frequency not allele frequency.
  • Increases homozygosity and decreases heterozygosity
62
Q

Sexual Selection

A
  • Selection based on success in courtship is a mechanism of evolutionary change.
  • Favours individuals with heritable traits that enhance their ability to obtain mates
  • If females invest a great deal in each offspring, then they should protect that investment by being choosy about their mates, males invest little and are therefore less choosy.
  • Selection should act more strongly on males than on females
    Females choose mates based on physical characteristics and resources and parental care ability of the male.
63
Q

Sexual Dimorphism

A

Refers to any trait that differs between males and females.

Biology 1M03 (3 decks)

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