Chapter 7 Flashcards
What are examples of adaptations?
Camouflage, hibernation, feather structure and mimicry
What is adaptations?
Adaptations are structures, behaviors or physiological processes that help an organism survive and reproduce in its environment.
Examples of things that limit an organisms ability to survive
Famine, severe weather, competition for space
What is extinction?
Survival of the species depends on the species ability to adapt. Those that don’t survive become extinct and disappear completely from the earth.
How do you adaptations develop?
They are the result of gradual, accumulative changes that help in organism survive and reproduce. It is possible because variation exist within a population.
What is variation?
It refers to differences between individuals which maybe structural, functional or theological. Not all variations become adaptions. Environmental conditions determine what kind of effect a variation has on the individuals ability to survive and reproduce.
What happens when a variation is helpful to a species?
Individuals with a helpful variation are more likely to survive & it also allows them to pass this variation on to their offspring. As a result, the variation becomes a trait of the population.
What causes variation species?
Variation occurs because of the genes that are present in an individual. Genetic variation is a result of the wide variety of genetic information in all individuals in a population.
Why does genetic variation happen?
Mutations are a permanent change in the genetic material of an organism. They are caused by errors in DNA copying or cells that are exposed to mutagens such as chemicals or radiation.
Are mutations good bad or neutral?
In most cases mutations are harmful to both cells in the organism
(for example cancer and genetic disorders)
If a mutation occurs in a somatic cell, it will disappear from a pop when the organism dies.
If it occurs in the gametes, it can be passed on to offspring and possibly remain in the pop.
What is artificial selection?
Also known as selective breeding, artificial selection is controlled breeding in which individuals that exhibit a particular trait are chosen as parents of the next generation.
(For example the wolf was one of the earliest species to be domesticated & all modern breeds of dogs descended from wolves)
Describe artificial selection in plant breeding
A specific trait is selected and seeds are kept from the best plants that exhibit this trait. This continues for many generations until the desired version of the trait is achieved. (Examples include corn tomatoes and broccoli)
What are some cons of artificial selection?
It limits genetic diversity within a population. As specific traits are favoured, alleles for other traits are reduced or eliminated. Favoured traits can be linked to alleles that are detrimental and this can lead to genetic disorders.
It is immutability?
It is the belief that species could not change and had not changed.
Example being the a mouse is and always has been a mouse, there is no change.
What did Comte de Buffon propose?
He challenged the idea of immutability by studying animal anatomy and physiology. He proposed that species did change over time.
