Unit B Chapter 4 Flashcards
What are structural adaptations?
Physical features and special body parts
Examples include fur or hair structure, shape of ears, camouflage or warning colouration, and leaf shape.
What do behavioural adaptations refer to?
How organisms act
Examples include hibernation, diurnal vs. nocturnal behavior, migration, and mating rituals.
What are physiological adaptations?
Systems present in an organism that allow it to perform certain biochemical reactions
Examples include bioluminescence, slime production, and poison production.
Fill in the blank: _______ adaptations refer to physical features and special body parts.
[Structural Adaptations]
True or False: Behavioural adaptations include physical features of an organism.
False
What type of adaptation involves hibernation and migration?
[Behavioural Adaptations]
Fill in the blank: _______ adaptations involve systems that perform biochemical reactions.
[Physiological Adaptations]
What is an example of a physiological adaptation?
Bioluminescence
Physiological adaptations enable organisms to perform specific biochemical processes.
List three examples of structural adaptations.
- Fur or hair structure
- Shape of ears
- Camouflage or warning colouration
What do physiological adaptations allow organisms to do?
Perform certain biochemical reactions
True or False: Camouflage is an example of a physiological adaptation.
False
What is selective advantage?
A mutation that enables an organism to survive its environment better, increasing its likelihood of survival and reproduction
When is selective advantage more likely to occur?
When an organism’s environment is changing
True or False: Mutations that were once advantageous can become disadvantageous in a new environment.
True
Fill in the blank: A mutation provides a _______ in a new environment.
selective advantage
What happens to mutations that were once a disadvantage when an environment changes?
They may become favorable in the new environment
What is the primary cause of variation in a population?
Sexual reproduction
Parents pass on units of hereditary to their offspring, leading to genetic diversity.
What contributes to the astronomical number of possible genetic combinations?
The genetic material inherited from parents
Each parent contributes a unique set of genes, resulting in diverse offspring.
What does the term ‘population variation’ refer to?
The increase in commonality of variations that aid survival and reproduction
Variations that help individuals survive become more prevalent over generations.
Fill in the blank: The number of possible combinations of genetic material is _______.
astronomical
True or False: Population variation occurs without the influence of sexual reproduction.
False
Sexual reproduction is essential for introducing variation in a population.
How does variation in individuals of the same species manifest?
Through differences among individuals
Even within a single species, such as Homo sapiens, there are numerous variations.
What is heritable mutation?
Random changes in the genetic code that can be passed on to offspring
Heritable mutations are crucial for the process of evolution as they introduce genetic variation.
What can cause mutations in DNA?
Mistakes during DNA copying and environmental conditions such as radiation or harmful chemicals
These factors can lead to changes in the genetic code, impacting organism traits.
What are the potential effects of mutations on organisms?
Mutations can be harmful, beneficial, or neutral. They may kill, cripple, or help an organism survive better
Beneficial mutations can enhance survival and reproductive success.
How do beneficial mutations affect an organism’s reproduction?
They enable the organism to reproduce more successfully than those without the mutation
This process can lead to the spread of beneficial traits in a population.
Fill in the blank: Mutations can arise due to _______ during DNA copying.
mistakes
Errors in DNA replication can lead to heritable mutations.
True or False: All mutations are harmful to organisms.
False
While some mutations can be harmful, others can provide advantages that enhance survival.
What causes variation in a population?
Mutations and sexual reproduction
These processes introduce genetic diversity within a population.
What happens to harmful variations in a population?
The organism dies and does not pass it on
Harmful variations typically reduce the survival and reproductive success of individuals.
What is the effect of beneficial variations on an organism?
Helps an organism and is passed on
Beneficial variations increase the likelihood of survival and reproduction.
How does variation become more common in a population?
It becomes an adaptation
Adaptations are traits that enhance survival and reproduction in a specific environment.
What is Natural Selection?
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 pass on their traits to their offspring
Natural Selection is a key mechanism of evolution.
What factors contribute to Natural Selection?
Specific local environmental conditions and inherited traits
These factors influence which organisms survive and reproduce.
True or False: Natural Selection only occurs in animals.
False
Natural Selection applies to all living organisms, including plants and microorganisms.
Fill in the blank: Natural Selection results in the _______ of certain traits in a population.
[change]
This change is due to the survival and reproduction of individuals with advantageous traits.
What is the outcome of Natural Selection over time?
Change in the characteristics of a population
This change can lead to the evolution of new species.
List the two main components of Natural Selection.
- Survival of individuals with advantageous traits
- Reproduction and passing on of those traits
These components are essential for the process of Natural Selection to occur.
Five points of Darwin’s theory of natural selection
1.All organisms produce more offspring than can actually survive
2.competition productions of more individuals than the environment can support leads to a struggle for existence
3. Variety the characteristics of inidiviuals of a given species vary
4. Survival of the fittest the inididivuals whose characteristics are best adapted to a given environment survive
5.those individuals that survive pass on their traits to their offspring.
Two main ideas of Darwin in his book
- Present forms of life have descended from ancestral species
2.mechanisms for modification is natural selection that takes place over a long period of time
What is homologous structure
Structures that have different forms in different organisms but develop from the same embryotic tissues
Analogous structures
Structures that evolve separately to perform a similar function different development same function
Vestigial organs
Organs that serve no useful function in a modern organism but show evidence of a common ancestor
Four ways speciation can happen
Behavioural, temporal, geographical, mechanical isolation
Mechanical
Reproductive structures that are physically incompatible
Temporal
Two population Reproduce at different times
Geographical
Separated by geographical barriers like river mountains etc
Behavioural
Have different mating and courtship rituals and other reproductive strategies that involve behavior
The two pathways that lead to speciation
Transformation and divergence
Transformation
Gradually develops from mutation and adaptation to environmental conditions and the old species is gradually replaced
Divergence
A population is isolated long enough mutations will accumulate and natural selection will occur species becoming more and more different is called divergent evolution
Two models of evolution
Gradualism and punctuation equilibrium
Punctuated equilibrium
In which short periods of drastic change in species include mass extinction and rapid speciation are separated by long periods of no change
Gradualism
Which slow changes happen over long periods of time. Big changes like evolution of a new species occur as a result of many small changes
Does evolution happen on a individual level
No it happens slowly on a population level
Adaptive radiation
Diversification of a common ancestral species into a variety of species all of which are differently adapted
Name all indirect evidence
Embryology homologous structure analogous structure vestigial organs biochemical evidence
Name all direct evidence
Biogeography fossil record transitional fossils
Three theories of lamarkism
The theory of need theory of use and disuse the theory that acquired traits can be passed to offspring
Buffon
Challenged the idea that life forms do not change. Common ancestry with apes and humans. Believed earth was more than 6000yrs old
Cuvier
Credited with developing the science of palaeontology found that each stratum is characterized by a unique group of fossils. Deeper the stratum the more dissimilar the species from modern life found that species appeared and disappeared this means species could become extinct. He thought earth experienced many destructive natural events which killed many species.
Lyell
Believed that geological processes on earth take a long time. If geological presses are slow and continuous rather than catastrophic then earth is more than 6000yrs old. Theorized slow processes over time could result in substantial changes. Proposed geological processes operated at the same rates in the past as they do today.
Lamarck
Early idea of how animals change over time. Organisms change over time and new species are modified descendants of old types. Many people are discussing Lamarckism when talking about evolution. In his theory her believed the environment is key in evolution but rest of theory is wrong (species increase complexity until they achieve perfection or big muscles could be passed to offspring.
Darwin
Many many observations regarding organisms made on the beagle voyage. He and Wallace published their theories at the same time but Darwin was credited. He was also credited with first to developed idea of natural selection with his book.
Wallace
Studies organisms in South America and Malaysia focused more on biogeography and how it affected species
Aristotle and Plato
Beloved that life rescued on earth in a perfect and unchanged form. Static and did not evolve or change over time.
Explain Darwin’s finches
Darwin’s finches are birds from the Galápagos Islands with different beak shapes depending on what they eat this shows how species can change over time to fit their environment supporting Darwin’s ideas of evolution by natural selection
Somatic mutation
Mutation not passed on to offspring don’t affect reproductive cells
Heritable mutation
Changes in dna that can be passed on to offspring
Theory of use and disuse
Says that traits become stronger if used often and weaker if not believed that giraffe’s ancestors stretched their necks and it passed down to offspring
Theory of inheritance of aquired characteristics
Traits acquired in a organisms lifetime can be passed on to its offspring
Theory of spontaneous generation
Believed that life could arrive spontaneously from nonliving matter
Theory of spontaneous generation
Believed that life could arrive spontaneously from nonliving matter
