Semester 2 Science - Taxonomy

What does the word taxonomy mean?

• The classification and naming of plants and bacteria in an ordered system that is intended to indicate natural relationships, especially evolutionary relationships.

• The classification and naming of organisms in an ordered system that is intended to indicate natural relationships, especially evolutionary relationships.

• The classification and naming of organisms into natural relationships that are identified according to what the animals eat and how they reproduce

• The classification and naming of animals in an ordered system that is intended to indicate natural relationships, especially evolutionary relationships.

Answer explanation

It is because all organisms are classified and named not only animals, plants or bacteria, and organisms are not classified according to what they eat or how they reproduce

What does a vertebrate animal have that an invertebrate animal does not?

• Heart, brain and intestines

• Well developed internal organs

• A spinal column or in other words a backbone

• Limbs and eyes

Answer explanation

Although there are a few differences between vertebrates and invertebrates, one of the main difference is that vertebrate animals have a spinal column or backbone, whilst invertebrates do not have this.

Are jellyfish, worms, snails and spiders vertebrates or invertebrates?

• They are both vertebrates and invertebrates

• They don't belong to either of theses groups

• Vertebrates

• Invertebrates

Answer explanation

Organisms are either vertebrates (have backbone) or invertebrates (don't have backbone) and all the animals listed in the question do not have a backbone.

Who was the first to create a system of organism classification?

• Swedish scientist Carl Linnaeus

• A group of American scientists

• English scientist Alfred Russel Wallace

• English scientist Charles Darwin

Answer explanation

There are more than one classification systems, but the one that is internationally accepted is the one that was created by Carl Linnaeus ( full name: Carolus Linnaeus).

Are tigers, pigs, chickens, frogs and fish vertebrates or invertebrates?

• Tigers, pigs and chickens are vertebrates but not frogs and fish.

• Vertebrates

• Invertebrates

• They don't belong to either groups

Answer explanation

All listed animals in this question are vertebrates as they all have a spinal column/backbone.

What is the name of the internationally used classification system and what does it mean?

• Darwinian system, which name organisms using only one word (e.g.: fish, monkey, elephant, etc.)

• Aristotelian system, which had three different groups (plants, animals and humans)

• Binominal nomenclature, which means that an organism has two names (genus and species)

• Binominal nomenclature, which means that an organism has two names (kingdom and phylum)

Answer explanation

It is called binomial (which means two names) nomenclature (which means system of names) and the Linnaean system has two names for all organisms: one is the genus and the other one is the species (e.g.: Ursus Americanus = Black Bear).

What does homologous trait mean?

• Animals have similar traits due to genetic relationship (opposable thumbs = chimpanzees & orangutans)

• Animals have similar traits due to the way they look (phenotypic relationship) (wings = birds & bats)

• It means that animals have some traits from other animals (e.g.: binocular vision)

• It refers to traits that all organisms have even if they are single celled organisms

Answer explanation

Homologous traits not only look similar, but are genetically related.

Do you think that the birds' wing and the bat's wing is a homologous or an analogous trait?

• It is neither analogous nor homologous.

• It hasn't been scientifically established yet

• It is an analogous trait

• It is a homologous trait

Answer explanation

It is an analogous trait as it evolved separately and bats and birds are genetically not closely related (well, all organisms are genetically related if one goes back far enough in evolutionary time).

What are the four qualities that define if an organism is an animal?

• Eater, mover, sexually reproducer and single cellular

• Eater, mover, sexually reproducer and multicellular

• Eater, drinker, sexually reproducer and multicellular

• Eater, mover, breather and sexually reproducer

Answer explanation

Eater, mover (plants don't move from their position, they only grow), sexually reproducer (bacteria, virus, etc. though can eat and move, but they reproduce asexually) and multicellular. Although, as you also saw it in the video the exact classifications can be tricky at times.

What do scientists use the molecular clock for?

• To estimate how long ago two species diverged by comparing their DNA sequences

• To analyse what the difference between animals, plants and single celled organisms by comparing their DNA sequences

• To analyse fossils and living animals and determine how similar they are by comparing their DNA sequences

• To see how many animals there are in the world by analysing their DNA sequences

Answer explanation

Molecular clock approach estimates the time between two species by looking at the similarities and differences in their DNA sequences, which helps to estimate when the common ancestor of those two species lived.