Deck 12: Diversity of Life

Question 1

Figure 12.3 In what levels are cats and dogs considered to be part of the same group?

Answer 1

The naming and grouping of plants based on presence and absence of certain characteristics is called a taxonomic classification. The earth is filled with massive flora and fauna and classifying them into taxa helps us to study them easily. The organisms are grouped into various hierarchical taxa from higher rank to lower rank where the lower rank being more specific. They are: domain-kingdom-phylum-class-order-family-genus-species.
Figure 12.3 shows the taxonomic classification of organisms according to their similarity. The domain is placed at the bottom of the taxonomic classification because it has the least similarity between the organisms. It can be seen that dogs are placed along with plants also. The cats and dogs are placed in the group are
1. Domain eukarya : this is because both the organisms are eukaryotic in nature.
2. Kingdom Animalia : both the organisms are animals which are characterized according to locomotion, body plan and metamorphosis.
3. Phylum chordata : they are placed in this group together because of the presence of notochords, dorsal nerve cord, endostyle and a tail.
4. Class mammalia : this group of organism will have mammary glands, four chambered heart, well develop nervous system that regulates the temperature and circulatory system. Both cats and dogs possess these characters.
5. Order carnivore : includes those mammals whose diet is dominated by meat. Both cats and dogs consume meat as their main diet.
After the level of order they are being placed in different family.

Question 2

Figure 12.8 Which animals in this figure belong to a clade that includes animals with hair? Which evolved first: hair or the amniotic egg?

Answer 2

A clade is that group of species formed in a cladistics and shares common derived characters. Several clades are formed at different branching points of the tree and those clades with a recent common ancestor and shared derived characters are called a monophyletic group.
A clade does not count the same basic characters because they are considered as shared ancestral characters and not derived ones and only those organisms possessing the same derived characters are placed in the same clade. Many clades are formed on the same tree based on shared derived characters. And each clade is different from the other.
Each member placed in the same clade will have different phylogenies as the shared derived characters can be formed at different timings of speciation.
In a tree , the species with a common ancestor is placed in different clades according to presence and absence of a derived character. If two or three species shares common derived characters, they will be placed in the same clade which will form a monophyletic group. In the figure 12.9 , a clade with hairs is formed by rabbit and human. Lizard, rabbit and human forms a monophyletic group in which the amniotic egg evolved. Lizard branches off first than rabbit and human which has hairs. This indicates that amniotic egg evolved first and with speciation , a new derived character of having hairs got evolved.
The amniota clade encompasses the clade with hairs because the amniotic egg character evolved before animals with hair.

Question 3

What is a phylogeny a description of?

A) mutations
B) DNA
C) evolutionary history
D) organisms on Earth

Answer 3

The study of evolutionary history and relationship between or among a group of species is called phylogeny. The study of phylogeny of a species allows us to understand the species gene lineage and how it has evolved with time.
Mutation is the alteration in the nucleotide sequence of a gene. This change in the DNA sequence can lead to deleterious effects on an organism.
Hence, the option (a) is incorrect.
DNA (deoxyribonucleic acid) is the genetic material of many species and phylogeny is the study of how DNA of organisms has changed with time.
Hence, the option (b) is incorrect.
Phylogeny is not the study of organisms on earth rather it's the study of how all the organisms have evolved with change in time.
Hence, the option (d) is incorrect.
Phylogeny is the tracing of evolutionary history of an organism's nucleotide sequence. Along with time, organisms have evolved its gene to adapt with the changing environment. This change in the sequence will trigger the formation of new organisms and the process is called Speciation. Phylogeny includes all the individual traits, characters, structures and nucleotide sequence that has allowed evolution of new species over time.
Hence, the correct answer is option .

Question 4

Which statement about the taxonomic classification system is correct?

A) There are more domains than kingdoms.
B) Kingdoms are the top category of classification.
C) A phylum may be represented in more than one kingdom.
D) Species are the most specific category of classification.

Question 5

Which best describes the relationship between chimpanzees and humans?

A) chimpanzees evolved from humans
B) humans evolved from chimpanzees
C) chimpanzees and humans evolved from a common ancestor
D) chimpanzees and humans belong to the same species

Question 6

Which best describes a branch point in a phylogenetic tree?

A) a hypothesis
B) new lineage
C) hybridization
D) a mating

Question 7

Which statement about analogies is correct?

A) They occur only as errors.
B) They are synonymous with homologous traits.
C) They are derived by response to similar environmental pressures.
D) They are a form of mutation

Question 8

What kind of trait is important to cladistics?

A) shared derived traits
B) shared ancestral traits
C) analogous traits
D) parsimonious traits

Question 9

What is true about organisms that are a part of the same clade?

A) They all share the same basic characteristics.
B) They evolved from a shared ancestor.
C) They all are on the same tree.
D) They have identical phylogenies.

Question 10

Which assumption of cladistics is stated incorrectly?

A) Living things are related by descent from a common ancestor.
B) Speciation can produce one, two, or three new species.
C) Traits change from one state to another.
D) The polarity of a character state change can be determined.

Question 11

A monophyletic group is a ________.

A) phylogenetic tree
B) shared derived trait
C) character state
D) clade

Question 12

How does a phylogenetic tree indicate major evolutionary events within a lineage?

Question 13

List the different levels of the taxonomic classification system.

Question 14

Dolphins and fish have similar body shapes. Is this feature more

Question 15

Describe maximum parsimony

Question 16

How does a biologist determine the polarity of a character change?