Biology: Classification of Living Things Worksheet

Question 1

List the main levels of biological classification from broadest to most specific.

Accepted Answer

The main levels from broadest to most specific are domain, kingdom, phylum, class, order, family, genus, and species.

Question 2

Two organisms are in the same genus but different species. Are they more closely related than two organisms in the same family but different genera? Explain.

Accepted Answer

Yes, two organisms in the same genus are usually more closely related because genus is a more specific classification level than family.

Question 3

The scientific name for the gray wolf is Canis lupus. Which word is the genus, and which word is the species name?

Accepted Answer

Canis is the genus, and lupus is the species name. Together, they form the scientific name Canis lupus.

Question 4

A student finds an organism that is made of many cells, has cell walls, and makes its own food using sunlight. Which kingdom does it most likely belong to?

Accepted Answer

The organism most likely belongs to the plant kingdom because it is multicellular, has cell walls, and makes its own food through photosynthesis.

Question 5

Explain why scientists use scientific names instead of only common names.

Accepted Answer

Scientists use scientific names because common names can vary by language or region. A scientific name gives each species a standard name that scientists around the world can understand.

Question 6

Use these traits to classify the organism: it has a backbone, feathers, wings, a beak, and lays eggs. What class of vertebrate is it most likely in?

Accepted Answer

The organism is most likely in the class Aves, which includes birds. Feathers, beaks, wings, and egg laying are common bird traits.

Question 7

What is the difference between a vertebrate and an invertebrate?

Accepted Answer

A vertebrate is an animal with a backbone. An invertebrate is an animal without a backbone.

Question 8

A dichotomous key step says: 1a. Has six legs, go to step 2. 1b. Does not have six legs, go to step 3. An unknown animal has eight legs. Which step should you go to next?

Accepted Answer

You should go to step 3 because the animal does not have six legs.

Question 9

Classify each organism as producer, consumer, or decomposer: grass, mushroom, rabbit.

Accepted Answer

Grass is a producer because it makes its own food. A mushroom is a decomposer because it breaks down dead matter. A rabbit is a consumer because it eats other organisms.

Question 10

A bacterium is single-celled, has no nucleus, and has DNA. Which domain does it belong to if it lives in normal soil and is not an extreme environment microbe?

Accepted Answer

It most likely belongs to the domain Bacteria because it is single-celled and has no nucleus.

Question 11

Look at these classification levels for a house cat: Animalia, Chordata, Mammalia, Carnivora, Felidae, Felis, Felis catus. Which level is the family?

Accepted Answer

The family is Felidae. It comes after order and before genus in the classification system.

Question 12

A cladogram shows that lizards and snakes share a more recent common ancestor with each other than either does with frogs. Which pair is more closely related: lizards and snakes, or lizards and frogs?

Accepted Answer

Lizards and snakes are more closely related because they share a more recent common ancestor on the cladogram.

Question 13

Why can physical appearance alone sometimes be misleading when classifying organisms?

Accepted Answer

Physical appearance can be misleading because unrelated organisms may look similar due to similar environments or lifestyles. Scientists also use DNA, body structures, development, and other evidence to classify organisms.

Question 14

A table lists four organisms. Organism A has a nucleus and is multicellular. Organism B has no nucleus and is single-celled. Organism C has a nucleus and is single-celled. Organism D has a nucleus and is multicellular. Which organism is definitely a prokaryote?

Accepted Answer

Organism B is definitely a prokaryote because it is single-celled and has no nucleus.

Question 15

Create a short classification description for a dolphin using these facts: it is an animal, has a backbone, breathes air with lungs, gives birth to live young, and nurses its young with milk.

Accepted Answer

A dolphin is an animal and a vertebrate. It is classified as a mammal because it breathes air with lungs, gives birth to live young, and nurses its young with milk.

Biology: Classification of Living Things

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