Topic 1 Definitions

Question 1

Define Biodiversity?

Answer 1

Variety of life, from the smallest microbe to the largest animals and plants, the genetic material that gives them their specific characteristics, and the ecosystems in which they survive.

Question 2

Define Adaptations?

Answer 2

Special structures and behaviours that allow it to survive in its environment

Question 3

Define abiotic factor?

Answer 3

Non-living elements in an ecosystem

Question 4

Define biotic factor?

Answer 4

Living elements in an ecosystem

Question 5

Define Hierarchical?

Answer 5

Grouping from larger general groups to specific detailed groups.

Add taxonomy tree?

Question 6

Define classification?

Answer 6

Arranging things into groups according to their observed similarities

Question 7

Define Taxonomy?

Answer 7

The science of naming and classifying living things based on physical and biochemical characteristics is called taxonomy.

Each category in the Linnaean system represents a level of grouping from a large general group (or taxon) to a smaller group with more specific characteristics.

Question 8

What are the three domains?

Answer 8

Bacteria, Archaea, Eukarya

Question 9

What are the two parts to naming an organism?

Answer 9

Genus name and specific name

Question 10

Define species?

Answer 10

Group of similar organisms whose members can interbreed with each other in their natural environments to produce living (i.e. viable), fertile (i.e. can breed) offspring

Question 11

What does it mean to be reproductively isolated?

Answer 11

Two different species cannot interbreed to produce offspring. This is referred to as being reproductively isolated.

Reasons for this:
Different behaviours
Different environments or physical barriers
Different genetic material

Closely related organisms have been known to interbreed in artificial situations (e.g. lions and tigers in zoos), but the hybrid offspring are usually sterile.

Question 12

What are the limitation with classifying other species that don’t reproduce sexually?

Answer 12

Classification - physical and reproductive powerpoint 1

Question 13

Define varieties?

Answer 13

Members of a species may differ, but not enough to be considered separate species. They are placed into categories called varieties.
– e.g. the poodle is a variety of dog

Question 14

Define subspecies?

Answer 14

Organisms have adaptations (e.g. different colour patterns) that better suit them to their particular habitats, but they still belong to the same species because they are still potentially capable of interbreeding.

Question 15

What Is an r-strategist?

Answer 15

An animal that has a:

Short lives
High exponential rates of reproduction
Quick o mature
Strong sex drive
Little care of offspring
E.g. insects, coral, rodents and bacteria

Question 16

What is a k-strategist?

Answer 16

An animal that has a:

Fewer offspring
Spend energy and time nurturing offspring
Take longer to reach sexual maturity 
Longer gestational periods
Generally live longer
E.g. elephants and sea turtles

Question 17

What is divergent evolution?

Answer 17

Evolution that leads to descendants becoming different in form from their common ancestor
Homologous structures- structures that share a similar internal structure, but have a slightly different function, share a recent common ancestor
The greater the number of homologous organs different species have, the closer is the relationship between them.

Question 18

What is convergent evolution?

Answer 18

the independent development of similarities between species as a result of their having similar ecological roles and selection pressures

Analogous structure -structures with a similar function but no structural relationship
E.g. wings of bats (with bones) and wings of insects (no bones)

Vestigial (vah-stidg-e-el) structure- structure with no apparent function, but which may have had a function in an ancestral species
E.g. the coccyx of humans

Comparative embryology- embryos of many animals closely resemble each other, even though the adults show wide divergence.

Question 19

Define cladistics?

Answer 19

A method of grouping organisms that uses evolutionary lines of descent rather than structural similarities

Question 20

Define phylogenetic tree?

Answer 20

Is composed of a series of branches where each separation is defined by a new feature

Question 21

Define clade?

Answer 21

A section that includes a ancestor and its descendants

Question 22

Define biodiversity?

Answer 22

Variety of life, from the smallest microbe to the largest animals and plants, the genetic material that gives them their specific characteristics, and the ecosystems in which they survive.

Question 23

Define ecosystems?

Answer 23

A biological community of interacting organisms and their physical environment

Question 24

What are the three types of grouping within phylogenetic trees?

Answer 24

Monophyletic group = common ancestor + all descendants.

Polyphyletic group = descendants.

Paraphyletic group = common ancestor + some descendants

Question 25

What is the first assumption about cladistics?

Answer 25

Change in characteristics occurs in lineages over time.

Only when characteristics change that we are able to recognize different lineages or groups.

Question 26

What is the second assumption about cladistics?

Answer 26

Any group of organisms is related by descent from a common ancestor. Supported by many lines of evidence and essentially means that all life on Earth today is related and shares a common ancestor

Question 27

What is the third assumption about cladistics?

Answer 27

There is a bifurcating, or branching, pattern of lineage-splitting. When a lineage splits, it divides into exactly two groups.

Question 28

What is molecular clock?

Answer 28

If two populations become isolated, they will accumulate differences in DNA over time.

Mutations occur in the DNA over time
DNA becomes different causing divergence.

The greater the difference in DNA between two species, the more time that has passed since a shared common ancestor.

Question 29

How does amino acid sequences work?

Answer 29

When the sequences of amino acids for the same protein are compared, the number of differences in the amino acids can be determined.

The greater the number of differences in amino acids between two organisms, the more time has passed for changes to accumulate since their common ancestor.

Question 30

What is in mitochondrial DNA?

Answer 30

Mitochondria contains 37 genes that code for 2 rRNA, 22 tRNA and 13 proteins.

Question 31

Define niche?

Answer 31

Organisms role in the ecosystem- includes the species’ requirements, the physical conditions and resources it needs.

Question 32

Define Habitat?

Answer 32

Organism’s living place with other organisms of the same species.

Question 33

Define Microhabitat?

Answer 33

A small habitat different from the surrounding larger habitat

Question 34

Define population?

Answer 34

When a number of the same species is living in the same habitat at the same time.

Question 35

Define community?

Answer 35

The different species living in the same habitat.

Question 36

Define biosphere?

Answer 36

Area of the world that provides homes for living things

Question 37

What are producers?

Answer 37

Producers are autotrophic (self-feeding) organisms that form complex organic compounds (that contain carbon and hydrogen atoms) from simple inorganic molecules including carbon dioxide or sulphur dioxide.

Chemosynthetic organisms (some prokaryotes) break down inorganic molecules to obtain energy, while.

Photosynthetic organisms such as plants and algae use the energy from sunlight. These organisms are the primary energy source for all the other organisms in the ecosystem.