Module 4.3 Flashcards

Question

What is phylogeny

Answer 1

The study of evolutionary relationships between species Involves how closely related the are Relates to how long ago their common ancestor was

Answer 2

How much time the species have had time to evolve separately to adapt and mutate More recent common ancestors = more closely related species

Answer 3

A group of organisms descended from one common ancestor - they belong to the same phylogenetic group

Answer 4

proposed the mechanism of natural selection At the Galapagos islands discovered variation between the same species on different islands Finches - wide variety but were all actually closely related concluded 1 species arrived and evolved into many different species

Answer 5

Independently came to the same conclusions as Darwin

Answer 6

Offspring appear genetically similar to parents No two individuals are identical Organisms have the ability to produce large numbers of offspring Populations in nature tend to stay fairly stable in size

Answer 7

There is a struggle to survive Better-adapted individuals survive and pass on their characteristics Over time a number of changes may give rise to a new population

Answer 8

in the past the world was inhabited by species that were different from those present today Old species have died out and new ones have arisen The new species that have appeared are often similar to the older ones found in the same place

Answer 9

certain biological molecules are found throughout the living world suggesting all species arose from one original ancestor 2 closely related species will have separated only relatively recently - their biological molecules are likely to be identical or very similar In species that took separate evolutionary paths a long time ago the biological molecules are likely to differ more Cytochrome C and DNA sequences show this pattern of changes

Answer 10

The presence of differences between individuals

Answer 11

Variation within a species

Answer 12

Variation between species

Answer 13

There are 2 extremes and a full range of intermediate values between the 2 with most individuals close to the mean

Answer 14

Often by more than one gene and environmental factors

Answer 15

When their are 2 or more distinct categories with no intermediate values

Answer 16

Usually regulated by a single gene Not influence by the environment

Answer 17

Inherited/genetic and environmental

Answer 18

Genes we inherit from our parents used to define our characteristics Combination of alleles we inherit is not the same as in any other living thing

Answer 19

Characteristics affected by the environment e.g. overfeeding leads to obesity and exposure to sunlight darkens skin tone

Answer 20

Many characteristics are caused by both environmental and genetic variation humans have become taller because of a better diet but you are still unlikely to grow tall if the rest of your family are short (limited by genes) Not all genes are active at one time e.g. puberty changes in the environment can directly effect which genes are active

Answer 21

A variation that helps the organism to survive

Answer 22

structural adaptations e.g. long roots rolled leaves in xerophytes

Answer 23

Behaviours an organism exhibits to survive e.g. when earthworms are touched they rapidly contract and withdraw into a burrow as they think it is a bird about to eat them

Answer 24

Ensures the correct functioning of cell processes e.g. guard cells

Answer 25

When two unrelated species living in similar environments evolve similar adaptations despite separate evolution they may look and behave similarly

Answer 26

A individual that had a characteristic which helps it to survive is more likely to live long enough to reproduce therefor passing on these adaptations to the next generation

Answer 27

Mutation creates alternative alleles creating genetic variation (intraspecific) - selection pressure selects variations that give an advantage Individuals with advantageous characteristic survive and reproduce successfully They pass on their advantageous characteristic The next generation will have a higher proportion of individuals with the successful characteristics environmental variation does not get passed on to offspring

Answer 28

pesticides are a very strong selection pressure if an insect is susceptible it will die if it has some sort of resistance the individual may survive Individuals with some resistance reproduce and pass on the resistance characteristic Resistance quickly spreads throughout the whole population

Answer 29

Can cause pests to accumulate in the food chain If they survive the application of the pesticide their predators may eat them and receive a larger dose of the insecticide

Answer 30

Powerful selection pressure if a bacteria is susceptible it will die if it has some sort of resistance the individual may survive (especially if the full course of antibiotics is not taken) Individuals with some resistance reproduce and pass on the resistance characteristic Resistance quickly spreads throughout the whole population

Module 4.3 Flashcards

Classification and evolution