three domains of life

Question 1

what is biological diversity

Answer 1

varieties of life which exist on earth

Question 2

what is taxonomy

Answer 2

science of classifying organisms

Question 3

why is classification important

Answer 3

allows us to understand the past evolutionary history and present diversity

Question 4

who made the Linnaean classification

Answer 4

carolus linnaeus (swedish botanist) in the 1700s

Question 5

what does the linnaean classification consist of

Answer 5

a hierarchy of groupings called taxa

Question 6

what are examples of unity in diversity of life

Answer 6

cell: is basic structural and functional unit of all organisms
DNA: universal genetic language for all organisms

Question 7

state an example of unity in the diversity of life

Answer 7

the architecture of cilia. eg of wind pipe and paramecium is the same

Question 7

what can a genetic code provide

Answer 7

evidence of common ancestry of all life

Question 7

what is the biological species

Answer 7

this is a group of population where members can interbreed producing fertile offspring, but can’t successfully breed with members of different groups

Question 8

what is phylogeny

Answer 8

evolutionary history of a species or group of related species

Question 9

what is phylogenetic tree

Answer 9

hypothesis of evolutionary relationships

Question 10

what is a branch point

Answer 10

represents the separation of two lineages from a common ancestor

Question 11

what is sister taxa

Answer 11

group that share an immediate common ancestor that’s not shared by any other groups

Question 12

what are the three domains of life

Answer 12

bacteria, archaea, eukarya

Question 13

which of the three domains of life are prokaryotes

Answer 13

bacteria and archaea

Question 14

what are prokaryotes

Answer 14

• were the first organism to exist on earth
• can thrive in any condition eg, hot , cold, acidic, salty

Question 15

describe prokaryotes

Answer 15

• mostly unicellular but some can form colonies
• they’re 0.5-5 micro meters which is smaller than eukaryotes which are 10-100 micro meters
• they have different shapes such as coccoid, rod and spiral

Question 16

describe bacteria

Answer 16

they have a cell wall made of peptidoglycan which is a network of sugar polymers that’s cross-linked by polypeptides

Question 17

describe archaea

Answer 17

• some can live in extreme environments and are called extremophiles. eg halophiles: high saline environment
  thermophiles: in very hot environments
• archaea’s have protein and polysaccharides but lack peptidoglycan

Question 18

what is the domain eukarya

Answer 18

• includes protists and three kingdoms:
• plant: produce food through photosynthesis
• animal: ingest their food
• fungi: absorb nutrients through roots

Question 19

what are the 4 types of tissue

Answer 19

epithelial, nervous, connective, muscle

Question 20

describe epithelial tissue

Answer 20

• covers the outside of body and lines the organs and cavities
• the cells are closely packed together
• there are different shapes such as cuboidal, squamous and columnar
• the different types are stratified, pseudostratified and simple

Question 21

describe connective tissue

Answer 21

• it binds and supports other tissues
• there are 3 types of tissue fibres made of protein: collagenous, reticular, elastic fibres
  -2 types of cells that are in connective tissue are: fibroblasts and macrophages

Question 22

what are the 6 major types of connective tissue

Answer 22

• loose connective tissue- holds organs in place
• adipose tissue- stores fat
• bone- mineralised and forms skeleton
• blood- blood cells
• cartilage- strength and flexibility
• fibrous tissue- in tendons and attach muscles to bone and ligaments

Question 23

describe muscle tissue

Answer 23

• responsible for nearly all body movements
• they have filaments of actin and myosin which allows muscles to contract
• there three types of muscle tissue are skeletal, cardiac and smooth muscle

Question 24

describe nervous tissue

Answer 24

• split into 2 categories: neurons which transmit electrical impulses and glia which form myelin that supports and protects neurons