A3.2 HL only

Question 1

Classification

Answer 1

the process of arranging organisms, both living and extinct, into groups based on similar characteristics

Question 2

binomial nomenclature

Answer 2

a system of naming plants and animals in which each species is given a name consisting of two terms of which the first names the genus and the second the species itself

Question 3

taxa

Answer 3

a group of one or more populations of an organism or organisms seen by taxonomists to form a unit

Question 4

paradigm shift

Answer 4

a fundamental change in the basic concepts and experimental practices of a scientific discipline

Question 5

Convergent evolution

Answer 5

occurs when organisms that aren’t closely related evolve similar features or behaviours, often as solutions to the same problems

Question 6

phyla

Answer 6

a major group of animals or in some classificationsplants sharing one or more fundamental characteristics that set them apart from all other animals and plants and forming a primary category of the animal or plant kingdom

Question 7

Cladistics

Answer 7

a method of hypothesizing relationships among organisms

Question 8

homologous traits

Answer 8

similarities in structures of these organisms even when the function was not the same

Question 9

common ancestor

Answer 9

an ancestral group of organisms that is shared by multiple lineages

Question 10

cladogram

Answer 10

a diagram that shows relationships between species

Question 11

clade

Answer 11

a grouping that includes a common ancestor and all the descendants (living and extinct) of that ancestor

Question 12

node

Answer 12

the point on a stem where a leaf or leaves are, or have been attached

Question 13

Homologous structures

Answer 13

similar physical features in organisms that share a common ancestor, but the features serve completely different functions

Question 14

Pentadactyl limb

Answer 14

any limb that has five digits(e.g. five fingers or toes) Pentadactyl limbs are present in many species from many groups of organisms, including mammals, reptiles and amphibians

Question 15

homologous molecule sequences

Answer 15

the degree of similarity in the genetic sequences of different proteins or molecules

Question 16

Mutations

Answer 16

a change in a DNA sequence

Question 17

Substitution

Answer 17

a type of mutation in which one nucleotide is replaced by a different nucleotide

Question 18

Deletion

Answer 18

A type of genetic change that involves the absence of a segment of DNA

Question 19

Insertion

Answer 19

a type of mutation that involves the addition of one or more nucleotides into a segment of DNA

Question 20

degenerate code

Answer 20

multiple codons, or sets of three nucleotides, can code for the same amino acid during protein synthesis

Question 21

mutagens

Answer 21

a chemical or physical agent capable of inducing changes in DNA called mutations

Question 22

carcinogens

Answer 22

a substance, organism or agent capable of causing cancer

Question 23

Molecular clock

Answer 23

measures the number of changes, or mutations, which accumulate in the gene sequences of different species over time

Question 24

Human Immunodeficiency Virus

Answer 24

a virus that attacks cells that help the body fight infection, making a person more vulnerable to other infections and diseases

Question 25

lymphocytes

Answer 25

a type of white blood cell that is part of the immune system. There are two main types of lymphocytes: B cells and T cells

Question 26

Acquired ImmunoDeficiency Syndrome

Answer 26

A disease caused by the human immunodeficiency virus (HIV). People with acquired immunodeficiency syndrome are at an increased risk for developing certain cancers and for infections that usually occur only in individuals with a weak immune system. Also called AIDS

Question 27

simian immunodeficiency virus

Answer 27

members of the Lentivirusgenus of Retroviruses that infect nonhuman primates such as monkeys, chimpanzees, and gorillas

Question 28

Zoonotic transmission

Answer 28

an infectious disease that is transmitted between species from animals to humans (or from humans to animals)

Question 29

Retrovirus

Answer 29

A type of virus that has RNA instead of DNA as its genetic material. It uses an enzyme called reverse transcriptase to become part of the host cells' DNA

Question 30

reverse transcriptase

Answer 30

 an enzyme that converts RNA into DNA, commonly found in retroviruses like HIV

Question 31

Bioinformatics

Answer 31

an interdisciplinary field of science that develops methods and software tools for understanding biological data

Question 32

Homology

Answer 32

similarity of the structure, physiology, or development of different species of organisms based upon their descent from a common evolutionary ancestor

Question 33

BLAST

Answer 33

finds regions of similarity between biological sequences. The program compares nucleotide or protein sequences to sequence databases and calculates the statistical significance

Question 34

Mitochondria DNA

Answer 34

the circular chromosomefound inside the cellular organelles called mitochondria

Question 35

parsimony

Answer 35

the principle that, out of all possible explanations for a phenomenon, the simplest of the set is most likely to be correct

Question 36

Root

Answer 36

the central trunk of a cladogram that indicates the ancestor common to all groups branching from it. A cladogram uses branching lines that end in a clade, which is a group of organisms sharing a common hypothetical ancestor

Question 37

Outgroup

Answer 37

assumes that one or more of the taxa are divergent from the rest of the taxa (ingroup)

Question 38

Reclassification

Answer 38

updating the classification of an organism based on modern cladistic techniques

Question 39

Red Pandas

Answer 39

bamboo eaters native to Asia's high forests. Despite these similarities and their shared name, the two species are not closely related

Question 40

Figworts

Answer 40

any of a genus (Scrophularia) of chiefly herbaceous often fetid plants of the snapdragon family with terminal cymes of small purple, yellow, or greenish flowers

Question 41

Domain

Answer 41

the highest taxonomic rank in the hierarchical biological classification system, above the kingdom level. There are three domains of life, the Archaea, the Bacteria, and the Eucarya

Question 42

Eubacteria

Answer 42

prokaryotic microorganisms consisting of a single cell lacking a nucleus and containing DNA is a single circular chromosome

Question 43

Archaea

Answer 43

single-celled microorganisms with structure similar to bacteria. They are evolutionarily distinct from bacteria and eukaryotes and form the third domain of life

Question 44

Eukaryotes

Answer 44

any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane that surrounds the nucleus

Question 45

endosymbiotic theory

Answer 45

proposes that mitochondria originated as free-living Alphaproteobacteria that were internalized by a pre-eukaryotic host cell, leading to the formation of the modern eukaryotic cell