Vocabulary
Variation makes it less likely that any adverse changes in the environment would wipe out an entire species. What one word defines the statement in italics.
Extinction
Which of the following is not heritable?
A. Eye colour
B. Hair colour
C. Height
D. None of the above
D
Height is somewhat heritable, however, environmental factors do play a role
Factors in the environment can lead to variation within a species. Give two examples.
Food, climate, light intensity, mineral availability and water
The importance of variation in species is that enables them to adapt. Explain.
It enables species to adapt to changing environmental conditions
What is variation?
Variation is any difference between the individuals of a certain species.
What is caused by differences in one's DNA?
A. DNA Variation
B. Environmental Variation
C. Genetic Variation
C
Genetic differences can lead to variation within a species. Give two examples.
Mutations, meiosis, sexual reproduction
Variation is necessary for selection to take place. Explain.
It provides the raw material on which natural selection can work, and essential for species to remain adapted and gradually improve over time.
What is Darwin's Theory and which animal did he use as evidence?
Darwin's theory explained how populations evolved and adapted to their environment over time. He did so by using the Galapagos finches.
Which of the following could not be used to describe a species?
A. A group of organisms sharing unique structural and functional characteristics
B. A group of organisms capable of reproducing with one another to produce viable offspring
C. A group of organisms sharing the same ecological niche
D. A group of organisms that have identical DNA
D
The ___________ islands is where Charles Darwin based his theory on natural selection.
The Galapagos islands
Explain how the 'melanic' peppered moths had a better chance of survival than their lighter counterparts.
At first, these moths were white with black speckles, allowing them to be well-camouflaged against the pale lichen-covered tree trunks they resided on. During the Industrial Revolution, however, a dark variety arose as a result of a dominant mutation. This mutation made them well-camouflaged against the tree trunks that had now turned black with soot. The melanic variety now has a selective advantage as birds and other predators won't be able to see them.
What is heritable variation?
Heritable variation refers to the genetic differences that exist between individuals within a population.
Which of the following are factual?
A. Parents pass on their traits to their offspring through their genes
B. Organisms tend to have to compete for limited resources to survive
C. Organisms that survive while competing for resources are usually identical
D. Natural Selection is the gradual accumulation of advantageous traits in a population over time
A, B and D
Darwin wrote a book on Natural Selection. Give its title and the date it was published.
“On the origin of Species” - November 24, 1859
How does heritable variation take place?
Traits are passed down from generation to generation through the transfer of genetic material from parents to offspring during reproduction. When these organisms reproduce, their genetic material is rearranged, leading to new combinations.
What are the four principles of natural selection? Briefly define each.
Variation - There is variation in traits within a population
Heritability - Traits are passed from parent to offspring
Differential Fitness - Individuals with certain traits have a greater reproductive success than others in their environment
Selection - Over time, the frequency of advantageous traits increases in the population through differential survival and reproduction.
Charles Darwin once said, “It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is most adaptable to change.”
True or False
True
What four observations did Darwin make?
All organisms overproduce - to keep their population at a steady size, far more offspring are produced than are required
Population tends to remain fairly constant over long periods of time
Individuals within a population differ
Some of these variations are inherited (passed from parent to offspring)
Seeing as there wouldn't be any differences within a population, natural selection would not take place. This way, all individuals would have an equal chance of surviving - leading to overpopulation.