Lecture 8- Reconstructing and using phylogenies II

Question 1

What is it called when plants reproduce by mating with another individual?

Answer 1

Outcrossing

Question 2

What do many outcrossing species have?

Answer 2

Mechanisms to prevent self fertilization

Question 3

What are species who have mechanisms to prevent self fertilization called?

Answer 3

Self- incompatible

Question 4

What are species who regularly fertilize themselves with their own pollen called?

Answer 4

Selfing species

They are self compatible

Question 5

How can it be established how many times self compatibility has evolved in a group of plants?

Answer 5

Conducting a phylogenetic analysis of outcrossing and selfing species

Question 6

In what genus and family has the evolution of fertilization mechanisms been examined?

Answer 6

Linanthus (genus)

Phlox (family)

Question 7

Linanthus is a group of plants with _______ breeding systems and pollinating systems.

Answer 7

Diverse

Question 8

What does petals does the outcrossing/self incompatible species in Linanthus have and what is it pollinated by?

Answer 8

Long petals

Pollinated by long tongue flies

Question 9

What petals does the self-compatible species of Linanthus have?

Answer 9

Short petals

Question 10

How many species of Linanthus were involved in the phylogenetic study?

Answer 10

12

Question 11

What information was used to reconstruct the phylogeny of Linanthus?

Answer 11

Nuclear ribosomal DNA sequences

Question 12

How was it determined what species were self compatible?

Answer 12

Artificially pollinating flowers with the plants own pollen or with pollen from other individuals and observing if viable seeds were formed

Question 13

Self incompatibility is:
a.Derived state
b.Ancestral state
In the genus Linanthus

Answer 13

B

Ancestral state

Question 14

How is the self incompatibility found in the Linanthus genus unusual?

Answer 14

Multiple origins of self-incompatibility has not been found in any other flowering plant family

Question 15

Why is it easier to change from self-incompatible to self-compatibility than the reverse change?

Answer 15

Self incompatibility depends on physiological mechanisms in both pollen and stigma and requires the presence of at least 3 alleles

Question 16

How is the physical aspect of self incompatibility in Linanthus unusual?

Answer 16

The pollen rejection site is the stigma

Site of pollen rejection vary greatly among other plant families

Question 17

How many times has self incompatibility evolved in Linanthus?

Answer 17

3 times

Question 18

Why were the different self compatible Linanthus species that were classified as one species now classified as separate species?

Answer 18

Phylogenetic analysis using ribosomal DNA showed them to be members of distinct lineages

Question 19

What are zoonotic diseases?

Answer 19

Diseases caused by infectious organisms that have been transferred to humans from another animal host

Question 20

What did phylogenetic analysis of immunodeficiency viruses show?

Answer 20

Humans acquired these viruses from two different hosts

Question 21

Where was HIV-1 acquired from?

Answer 21

Chimpanzees

Question 22

Where was HIV-2 acquired from?

Answer 22

Mangabeys

Question 23

Where is the HIV-1 form of the virus more common and why?

Answer 23

Human populations in central Africa

Where chimpanzees are hunted for food

Question 24

Where is the HIV-2 form of the virus more common and why?

Answer 24

West Africa

Sooty mangabeys are hunted for food

Question 25

What does the distribution of HIV viruses infer about how HIV entered the human population?

Answer 25

Viruses entered human population through hunters who cut themselves while skinning chimpanzees/ sooty mangabeys

Question 26

What is the genus that swordtail fish belong in?

Answer 26

Xiphophorus

Question 27

What do male swordtails have that is associated with reproductive success?

Answer 27

Long, colorful extensions of the tail

Question 28

Male swordtails with long swords are more likely to mate successfully than males with short swords. This is an example of...

Answer 28

Sexual selection

Question 29

What is the sensory exploitation hypothesis?

Answer 29

Swords exploit a preexisting bias in the sensory system of the females

Question 30

What was used to identify the closest relatives of swordtails before the evolution of the sword?

Answer 30

A phylogeny

Question 31

What is the closest relative to swordtails?

Answer 31

platyfishes (another group of Xiphophorus)

Question 32

How was the sensory exploitation hypothesis tested?

Answer 32

Attaching artificial swordlike structures to some male platyfishes- females preferred this, supporting the hypothesis

Question 33

Why is a new flu vaccine needed every year?

Answer 33

Rate of evolution of the Influenza virus is so high that flu viruses that circulate each year are substantially different to previous years

Question 34

What is hemagglutinin?

Answer 34

A protein on the surface of influenza viruses that is recognized by the human immune system

Question 35

What does phylogenetic analysis of influenza strains indicate?

Answer 35

- Strong selection by human immune system against most strains - Strains with greatest number of amino acid replacements on hemagglutinin are likely to survive

Question 36

How do biologists predict which of the currently circulating strains of Influenza virus are most likely to survive and leave descendants in the future?

Answer 36

By conducting phylogenetic analysis of hemagglutinin

Question 37

Who started the biological classification system and when?

Answer 37

Carolus Linnaeus | mid 1700s

Question 38

What is the name of system of biological classification created by Carolus Linnaeus?

Answer 38

Binomial nomenclature

Question 39

What is the advantage of binomial nomenclature?

Answer 39

Scientists can unambiguously refer to the same organisms by the same names

Question 40

Define genus.

Answer 40

A group of related, similar species recognised by taxonomists with a distinct name used in nomenclature

Question 41

In the Linnaean system, how are species and genera further grouped?

Answer 41

A hierarchical system of higher taxonomic catagories

Question 42

Name the taxonomic categories.

Answer 42

``` Kingdom Phylum Class Order Family Genus Species (kinky people can often find good sex) ```

Question 43

What is a limitation of the Linnaean system categorizing organisms?

Answer 43

Ranked levels of classification is subjective | Used largely for convenience

Question 44

What are biological classification systems used to express?

Answer 44

Relationships among organisms

Question 45

Define monophyletic.

Answer 45

The taxon contains an ancestor and all decedents of that ancestor, and no other organisms. (also known as a clade)

Question 46

What is a group that does not include the common ancestor referred to as?

Answer 46

polyphyletic group

Question 47

What is a group that does not include all the descendants of a common ancestor referred to as?

Answer 47

A paraphyletic group

Question 48

Why do some classifications still used today still include para and poly phyletic groups?

Answer 48

Some organisms have not been evaluated phylogenetically.

Question 49

When more than one name is proposed to name a species, what do the rules specify the name should be?

Answer 49

The name first proposed

Question 50

Why are there duplicated names in taxonomy?

Answer 50

Historical separation of zoology, botany and microbiology

Question 51

Give an example of duplicated names arising from historical separation of fields within biology.

Answer 51

Drosophilia is a genus of fruit flies and a genus of fungi