Chapter 10 - Classification and Evolution

Question 1

What are the seven taxonomic groups?

Answer 1

Kingdom, Phylum, Class, Order, Family, Genus, and Species

Question 2

What is the new level of classification in the hierarchy?

Answer 2

Domain - this level of classification is placed at the top of the hierarchy.

Question 3

Why do scientists classify organisms?

Answer 3

To identify species - by using a clearly defined system of classification, the species an organism belongs to can be easily identified.
To predict characteristics - if several members in a group have a specific characteristic, it is likely that another species in the group will have the same characteristic.
To find evolutionary links - species in the same group probably share characteristics because they have evolved from a common ancestor.

Question 4

What are the 3 domains?

Answer 4

Archaea, Bacteria and Eukarya

Question 5

What is a species?

Answer 5

A group of organisms that are able to reproduce to produce fertile offspring.

Question 6

How does the binomial nomenclature of naming work?

Answer 6

First word is the organisms genus, and second is its species. (written in italics or underlined, with the genus in upper case)

Question 7

What is the levels of hierarchy for a human?

Answer 7

Eukarya, Animalia, Chordata, Mammalia, Primates, Hominidae, Homo, Sapiens

Question 8

What are the five kingdoms?

Answer 8

-Prokaryotae(bacteria)
{prokaryotes}
-Protoctista(the unicellular eukaryotes ) {eukaryotes}
-Fungi(yeasts, moulds, mushrooms) {eukaryotes}
-Plantae {eukaryotes}
-Animalia {eukaryotes}

Question 9

What are the features of Prokaryotae?

Answer 9

• unicellular
• no nucleus or other membrane bound organelles (ring of naked DNA and small ribosomes)
• no visible feeding mechanism

Question 10

What are the features of Protoctista?

Answer 10

• mainly unicellular
• has a nucleus and other membrane bound organelles
• some have chloroplast
• some are sessile, but others move by cilia or by amoeboid mechanims
• nutrients are acquired by photosynthesis

Question 11

What are the features of Fungi?

Answer 11

• uni or multicellular
• nucleus with other membrane bound orgnalles and cell wall made of chitin
• no chloroplast
• no mechanism for locomotion
• most have a body or mycelium made of threads or hypae
• most store their food as glycogen

Question 12

What are the features of Plantae?

Answer 12

• multicellular
• all contain chloroplast
• most dont move
• nutrients are acquired by photosynthesis(autotophic)
• store food as starch

Question 13

What are the features of Animalia?

Answer 13

-Multi cellular
-no chloroplast
move with aid of cilia, flagella, or contractile proteins sometimes in the form of muscular organs
-nutrients are acquired by ingestion (heterotrophic)
-food stored as glycogen

Question 14

What is the current classification system used by scientists?

Answer 14

The Three Domain System. Proposed by Carl Woese (microbiologist)
The system organises organisms based on differences of nucleotides in the cells ribosomal RNA as well as cells membrane lipid structure and their sensitivity to antibiotics.

Question 15

What is the Prokaryotae kingdom divided into in Woeses system?

Answer 15

Archaebacteria and Eubacteria - this will mean there will be 6 kingdoms

Question 16

What is Phylogeny

Answer 16

Phylogeny is the name given to the evolutionary relationships between organisms. The study if the evolutionary history pf groups of organisms is known as phylogenetics.

Question 17

what sources do scientists use to study the process of evolution?

Answer 17

• Palaeontology = the study of fossils and the fossil record
• Comparative anatomy = the study of similarities and differences between organisms anatomy
• Genetics

Question 18

What are fossils?

Answer 18

They are formed when animal and plant remains are preserved in rocks.

Question 19

What is the fossil record?

Answer 19

They’re formed when animal and plant remains are preserved in rocks. Within different rock strata the fossils found are quite different, forming a sequence from oldest to youngest, which shows that organisms have gradually changed over time. Study of fossils = palaentology

Question 20

How do fossils show evidence of evolution?

Answer 20

• simplest organisms such as bacteria are in the oldest rocks, whereas complex organisms are found in more recent rocks
• Sequences in which organisms found match their ecological links. eg. plant fossils appear before animals
• Similarities in anatomy
• Fossils allow relationships between extinct and living organism to be investigated

Question 21

\whats a homologous structure?

Answer 21

a structure that appears superficially different (and may perform different functions) in different organisms, but has the same underlying structure. An example of this is the pentadactyl limb of vertebrates.

Question 22

What is divergent evolution?

Answer 22

The presence of homologous structures provides evidence for divergent evolution. This describes how, from a common ancestor, different species have evolved, each with a different set of adaptive features.This type of evolution will occur when closely related species diversify to adapt to new habitats as a result of migration or loss of habitat.

Question 23

What is Comparative biochemistry?

Answer 23

The study of similarities and differences in the proteins and other molecules that control life processes. Two most common molecule = cytochrome c (protein involved in respiration) and ribosomal RNA

Question 24

Whats the hypothesis of neutral evolution?

Answer 24

The hypothesis of neutral evolution states that most of the variability in the structure of a molecule does not affect its function. This is because most of the variability occurs outside of the molecules functional regions, changes that do not affect a molecules function are called ‘neutral’. - since they do not effect the function, their accumulation is not affected by natural selection. As a result, neutral substitutions occur at a fairly regular rate.
- Two discover how closely two species are related, the molecular sequence of a particular molecule is compared. The number of differences that exist are plotted against the rate the molecule undergoes neutral vase pair substitutions.

Question 25

What is variation?

Answer 25

The differences in characteristics between organisms

Question 26

What is interspecific variation?

Answer 26

variation between members of different species

Question 27

What is intraspecific variation?

Answer 27

Differences between organisms within the same species.

Question 28

What are the causes of variation?

Answer 28

• An organisms genetic material (genetic differences) = genetic variation
• The environment in which the organism lives = environmental variation

Question 29

What factors that cause genetic variation?

Answer 29

1. Alleles (variant) - individuals in a species population may inherit different alleles of a gene
2. Mutations - changes to the DNA sequence can result to changes in the protein that is coded for. These proteins can affect the physical and metabolic characteristics. If these mutations occur in the gametes it can be passed along however in the mutation is to somatic (body) cells it will only affect the individual
3. Meiosis - each gamete receives half the genetic content of a parent cell. Before the nucleus divides and chromatids of chromosomes separate, the genetic material inherited from the two parents are mixed up by independent assortment and crossing over.
4. Sexual reproduction - the offspring produces from two individual inherits genes (alleles) from each parent
5. Chance - due to random fertilization - each offspring in unique depending on the random combination of genetic material.

Question 30

What is the difference between continuous and discontinuous data/variation?

Answer 30

Discontinuous data can only have certain values (discrete variation) e.g eye color or gender (genetic characteristics. = data usually plotted on bar or pie charts
Continuous data can take any value within a range and is said to show continuous variation. There is a graduation from one extreme to the other of a characteristic - this is known as continuum. e.g height or mass = controlled by a number of genes (polygenes) = data usually collected in frequency tables or histograms.

Question 31

What is a normal distribution curve?

Answer 31

Normal distribution characteristics;

• the mean, mode and median are the same
• the distribution has a characteristic ‘bell shape’ which is symmetrical about the mean
• 50% of values are less than the mean and 50% is greater than the mean
• Most values lie close to the mean value

Question 32

What is standard deviation?

Answer 32

It is a measure of how spread out the data is.

Question 33

What is a students t test and the Spearmans rank correlation coefficient?

Answer 33

t test - It is used to compare the mean values of two sets of data (data must be normally distributed)
Spearmans rank correlation coefficient - this is used to consider the relationships between two sets of data

Question 34

What are adaptations?

Answer 34

Adaptations are characteristics that increase an organism chance of survival and reproduction in its environment.

• Anatomical adaptations - physics features (Body covering such as scales or spines, camouflage, Teeth, mimicry of animals body
• Behavioral adaptations - the way in which an organism acts (either inherited or learnt) (Survival behaviors, courtship, seasonal behaviors {migration and hibernation}, innate of instinctive behaviors, learnt behaviors)
• Physiological adaptions - processes that take place inside the organisms (poison production, antibiotic production, water holding)

Question 35

What are analogous structures?

Answer 35

structures that have adopted to perform the same function but have a different genetic origin (eg. tail fins of a whale and a fish)

Question 36

What is convergent evolution?

Answer 36

convergent evolution takes place when unrelated species begin to share similar traits. These similarities evolve because the organisms adapt to similar environments or other selection pressures.