5.4

Question 1

What is a clade

Answer 1

a group of organisms that have evolved from a common ancestor

Question 2

What can physical traits or characteristics be

Answer 2

analogous or homologous

Question 3

what are analogous traits

Answer 3

those that evolve separately but have similar functions, often organisms will share a similar habitat which similar selection pressures. They may develop complementary characteristics to help them live in that habitat however these characteristics did not evolve from each other.

Question 4

what is convergent evolution

Answer 4

convergent evolution is the independent evolution of similar features in species of different lineages

usually it is caused by organisms who have evolved alongside each other as a response to selection pressures and developed complementary characteristics.

Question 5

What does convergent evolution form

Answer 5

analogous features

Question 6

What is an example of convergent evolution

Answer 6

the fusiform shape of the penguin and the dolphin, they have evolved a similar shape suited for an aquatic environment

Question 7

What are homologous traits

Answer 7

characteristics shared by organisms because of their common ancestry.

Question 8

What is divergent evolution

Answer 8

the process whereby groups from the same common ancestor evolve and accumulate differences, resulting in the formation of new species. It may occur as a result of changes in abiotic factors, such as changes in environmental conditions or when a new niche becomes available.

Question 9

What is an example of divergent evolution

Answer 9

finches of the Galápagos Islands

Question 10

Give an example of analogous features

Answer 10

insect wings and bat wings

Question 11

Give an example of homologous structures

Answer 11

Human pentadactyl limb and bats

Question 12

How can evidence for which species are part of a clade be obtained

Answer 12

from the base sequences of a gene or the corresponding amino acid sequence of a protein.

Question 13

What do cladograms represent

Answer 13

when divergence of species into clades occurred along the evolutionary chain

Question 14

What is a clade

Answer 14

a group of organisms, both extant and extinct that share an ancestor

Question 15

What is important to remember when comparing sequences between species

Answer 15

amino acid sequences are not as accurate as DNA comparisons

Question 16

What is the molecular clock

Answer 16

a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in pre-history when two or more life forms diverged

Question 17

How do researchers check the conversion of differences in base sequence to units of geologic time

Answer 17

by checking the fossil record

Question 18

what regions of DNA provide the most information for analysis of similarities and differences in species

Answer 18

the non-coding region of DNA

Question 19

How does DNA give evidence of common ancestry between species

Answer 19

mutations occur gradually over time

the genetic code is universal

all living organisms use DNA as their source of genet information

Question 20

what does it mean in terms of evolution when genes are more conserved

Answer 20

they evolve more slowly

Question 21

What is a node

Answer 21

a point on a cladogram where divergence occurs, also known as the branching point

Question 22

what does it mean if there are lots of nodes between species

Answer 22

they are more distant in relationship

Question 23

what do we assume about mutations at the DNA and protein level in cladograms

Answer 23

that they occur at a constant rate

Question 24

what is the root of a cladogram

Answer 24

the point prior to any divergence where the organisms share certain characteristics

Question 25

what is an outgroup in the cladogram

Answer 25

the most distantly related organism on a cladogram, it has the longest branch of the tree and is set apart

Question 26

What is phylogenetic tree

Answer 26

a dirgram that represents evolutionary relationships among organisms based on their physical and genetic similarities and differences

Question 27

what allowed scientists to improve cladistics analysis

Answer 27

DNA base-sequence technologies

Question 28

what has evidence from cladistics shown

Answer 28

the classification of some groups based on structure did not correspond with the evolutionary origins of a group or species

Question 29

what does the figwort family demonstrate

Answer 29

how DNA sequence analysis has changed the classification landscape

Question 30

what did scientist find on figwort families

Answer 30

when they compared their chloroplast DNA, they found that what they believed was one clade, was actually 5 clades.

Question 31

what did scientist find on figwort families

Answer 31

when they compared their chloroplast DNA, they found that what they believed was one clade, was actually 5 clades.

Question 32

what is the best classification system

Answer 32

one that reflects evolutionary history

Question 33

why were the figwort family reclassified

Answer 33

because evidence showed that the species within the family did not all come from the common ancestor

Question 34

Charles Darwin used domesticated animals to provide evidence for evolution by natural selection. What is this evidence?

Answer 34

Differences between breeds show that selection can cause species to change.

Question 35

Ants, bees and wasps are classified in the same order. What can be deduced about these animals?

Answer 35

They are classified in the same class.

Question 36

Which organisms have flowers?

Answer 36

Angiospermophyta

Question 37

How can molluscs and platyhelminthes be distinguished?

Answer 37

Molluscs have a mouth and an anus but platyhelminthes do not.

Question 38

To which domain does Carcharodon carcharias, a shark, belong?

Answer 38

Eukaryote