Biology Chapter 26

A human is classified in domain _____ and kingdom _____.

Eukarya ... Animalia

Why do researchers use rRNA in investigations of relationships between taxa that diverged hundreds of millions of years ago?

DNA coding for rRNA changes relatively slowly.

In the five-kingdom system, prokaryotes are placed in the kingdom _____.

Monera

In the five-kingdom system, which kingdom consists primarily of unicellular eukaryotes?

Protista

In order for the COI gene to be useful for distinguishing among the different salmon species, which three statements must be true?

The COI gene must be conserved enough that the sequences can be aligned for comparison. The COI gene must be variable enough that there are at least a few differences between each salmon species. The COI gene must be conserved enough that the same PCR primers work for all the species being tested.

The tree includes the most recent common ancestor of all living species of bears (branch point 1). What does this tell you about this phylogenetic tree?

This phylogenetic tree is rooted.

By definition a clade is _____.

monophyletic

Molecular clocks are based on the idea that _____.

on average neutral mutations arise at a constant rate

There is(are) _____ eukaryotic domain(s).

one

Based on the results of the 2000 study, how should the portion of the tree extending from branch point 7 be altered?

---- Mainland Bear --ABC Brown Bear --- --Polar Bear

Place the following steps of the DNA extraction and PCR process in the correct order. Not all labels will be used.

1. Cut out a clean section of muscle tissue. 2. Disrupt cell, nuclear, and organelle membranes to release their contents into solution. 3. Eliminate non-Dna molecules using wash buffers. 4. Add Taq, primers, and dNTPs to the DNA sample. 5. Use a thermal cycler to denature, anneal, and extended the target sequence (the COI gene) in 35 cycles.

Prokaryotic cells are found in the domain(s) _____.

Bacteria and Archaea

Which observation supports the position of eukaryotes at the convergence of the "ring of life"?

The nuclear genome of eukaryotes contains genes from archaeans and from bacteria.

In the two-kingdom system, why were fungi classified in the kingdom Plantae?

They are sedentary.

Based on the revised branch of the tree, what kind of group do brown bears plus ancestral species 7 represent?

a paraphyletic group

Which branch point represents the most recent common ancestor of all bears?

branch point 1

Which branch point represents the most recent common ancestor of the sloth bear and the spectacled bear?

branch point 2

Which branch point represents the most recent common ancestor of the Asian black bear and the brown bear?

branch point 4

Animals that possess homologous structures probably _____.

evolved from the same ancestor

Fossil evidence indicates that some dinosaurs had feathers. If birds are indeed descended from dinosaurs, feathers are what kind of character?

shared ancestral character

Which of the following groups of species is a monophyletic group, or clade?

sun bear, Asian black bear, American black bear, ancestral species 5, ancestral species 6

Identify the sister taxon to the polar bear.

the brown bear

Which species is the basal taxon in this tree?

the giant panda

According to this tree, is the sun bear more closely related to the sloth bear or the polar bear?

the polar bear