bio Flashcards

(40 cards)

1
Q

Theory of inheritance of acquired characteristics

A

Interactions between individuals and their environment are important in the evolutionary process
However, it also proposed incorrectly that evolutionary change occurs during the lifetime of single individuals
Giraffe

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2
Q

Homology

A

Similarities are shared between organisms because they were inherited from the same structures in a common ancestor.
Testing Homology in the similarity of morphology and development
We use homologous traits to reconstruct evolutionary relationships

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3
Q

Ancestral Homology

A

characteristics that are shared through very remote or distant common ancestry

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4
Q

Derived homology

A

a feature that is diagnostic for a specific taxon, meaning that feature was acquired by the last common ancestor of that taxon and is shared by all members of the group

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5
Q

Principles of Classification

A

Kingdom
Phylum
Class
Order
Family
Genus
Species

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6
Q

Analogy

A

Structures that are similar among organisms in appearance or properties (function) but are inherited from different precursors

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7
Q

Two major categories of classification

A

Analogy and homology

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8
Q

Adaptive Radiation

A

When a single kind of organism diversifies to fill different ecological niches
Original species with evolutionary novelty quickly yield descendent species with that novelty
think advantageous trait!
Each descendent represents some new variation on that novelty
Exploit the environment in different ways

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9
Q

Major Modes of Speciation: Cladogenesis

A

Splitting of one lineage into two or more distinct lineages

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10
Q

Major Modes of Speciation: Anagenesis:

A

One species evolves over time

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11
Q

Reproductive Isolating Mechanisms: Seasonal isolation

A

breeding seasons do not correspond

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12
Q

Reproductive Isolating Mechanisms: Sexual isolation

A

courtship behaviors

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13
Q

Reproductive Isolating Mechanisms: Mechanical isolation

A

incompatibility in the structure of male and female sexual organs

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14
Q

Reproductive Isolating Mechanisms: Various post-mating mechanisms

A

Sterility

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15
Q

Biological Species Concept:

A

Groups of inter-breeding natural populations are reproductively isolated from other such groups.
Reproductive isolation
Physical barriers
Intrinsic barriers

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16
Q

Recognition Species Concept

A

Emphasizes unique traits or behaviors that allow individual members of the same species to recognize each other for the purposes of mating
Potential mates from different populations may not recognize each other * Coloration, calls, etc.

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17
Q

Ecological Species Concept

A

A group of organisms exploiting a single ecological niche and natural selection reinforcing species boundaries.

18
Q

Evolutionary Species Concept

A

Used to study the fossil record
Defines species as evolutionary lineages (ancestral-descendant sequences of populations) with their own unique identity

19
Q

Sex cells

A

Ova, egg cells produced in female ovaries
Sperm, sex cells produced in Male testes
Pass genetic information from one generation to the next
Haploid (N) only contains half the number of chromosomes
zygote - the union between a sperm and an ovum
- meiosis

20
Q

Somatic Cells

A

Components of body issues
Duplicate to replace dying cells and repair dying tissues
Diploid (2N) - contains a full complement of 46 chromosomes
- Mitosis

21
Q

Autosomes:

A

Responsible for determining traits, and an abnormal number is often fatal.

22
Q

Sex Chromosomes:

A

Responsible for the determination of male characteristics in mammals; an abnormal number is not fatal.

23
Q

Mutation

A

Only mutations occurring during Meiosis are heritable.
= A problem with DNA replication
copying errors
= the only source of new variation
== Natural selection increases the frequency of positive mutations
== Natural selection decreases the frequency of negative mutations
- mutation is random

24
Q

Genetic Recombination: Random Assortment

A

Reshuffling of genetic material from the parents via the random arrangement of chromosomes on the equator of the cell during the first division of Meiosis.
Thus, while each cell ends up with a complete set of chromosomes, unequal amounts have been inherited from father and mother

25
Genetic Recombination: Crossing Over
Homologous chromosomes come together in the nucleus – one inherited from each parent Line up side by side at the equator of the cell Adjacent non-sister chromatids crossover one another and exchange genetic material Crossing-over occurs at the same regions; genetic loci are in the same position What happens in a reshuffling of genetic information
26
Genetic Recombination
repackaging of maternally and paternally inherited genetic material in novel ways, creating an infinite number of new genetic combinations to produce much of the phenotypic variation observed among individuals.
27
Cell Division Process: Mitosis
Prophase Replicate, identical chromatids join at the centromere. Metaphase The chromosomes line up in a single file line along the middle of the cell with one sister chromatid – one copy of DNA – positioned on each side of the equator. Anaphase Sister chromatids are pulled apart at their centromeres. As this happens, one copy of the genetic material goes in one direction, and the second copy moves in the other direction. Telophase The cell divides. The result is two identical daughter cells.
28
Mitosis
Process in which Somatic Cells divide Occurs on somatic or body cells: skin, muscles, bones, organs Occurs during the growth or replacement of tissues Result: 2 Diploid cells , each cell will have 46 chromosomes
29
Meiosis
Production of gametes (sex cells) Characterized by two rounds of division that result in four daughter cells, each of which contains 23 chromosomes (4 haploid cells) in humans. Fertilization restores the zygote's full complement of chromosomes (diploid number of 46).
30
Meiosis First Reduction Division
Interphase DNA, replication Prophase I *Crossing over (genetic recombination) Metaphase I Chromosomes align in homologous pairs, a random assortment of chromosome members with respect to either side of the equator. Anaphase I Chromosome pairs separate (Reduction Division) Telophase I Interkenesis I Two haploid daughter cells, which are genetically dissimilar; no DNA replication
31
Chromosomes
Special Packaging for DNA Unique structure that keeps DNA tightly wrapped around proteins called histones in the form of chromatids during other phases of life
32
DNA Function: Cellular Replication
DNA is the unit of inheritance in most living organisms Provides the means to pass this information on to daughter cells
33
DNA Function: Protein Synthesis
DNA carries the instructions for making the components of a cell
34
DNA Made up Four nucleotides
Adenine Thymine Cytosine Guanine
35
Law of independent assortment
The distribution of one pair of factors into the gametes does not influence the distribution of other factors Factors controlling for two different traits assort independently of one another In other words, seed color is inherited independently of seed shape
36
Dihybrid Cross
Regardless of how the seed color factors segregate, the seed coat factors will segregate independently.
37
Law of segregation
During the formation of the sex cells (=gametes), the paired unit factors separate, or segregate, randomly, such that each sperm or egg receives one or the other factor with equal likelihood
38
Dominant and Recessive Traits
When two different factors relate to a characteristic, only one is expressed (dominant) while the other is not (recessive) There must be two copies of the recessive factor present for a recessive form to be expressed.
39
Natural Selection
competition for sources variation in population different fitness - some are better than others offspring of successful members survive Advantageous traits stick around Disadvantageous traits die out
40
Adaptation
Something that increases fitness - Is relative - Something good for one can be bad for another