How new species form
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
Read this first
A case card about model plants (model data)
when what happened start One plant species lives in one wide valley middle A new river splits it into two groups, and each group changes in its own way over many generations end The two groups can no longer interbreed, so there are two species Ari reads a case card about model plants. Which word names the whole process of one species becoming two species?
- Adaptive radiation: one founder species gives rise to many species
- Speciation: one species becomes two separate species
- Polyploidy: a plant gains extra sets of chromosomes
- Timing isolation: groups reproduce at different times of the year
Two groups of model fish in one lake (model data)
group what scientists found group P Its members interbreed with each other group Q Its members interbreed with each other P with Q Members of P and Q cannot interbreed Bo reads a note about two groups of model fish. Which word names the inability of group P and group Q to interbreed?
- Gene flow: alleles move freely between the groups
- Mutation: a change in the DNA sequence of a gene
- Reproductive isolation: the groups cannot interbreed
- Dispersal: a few members move to a new area
A case card about model birds (model data)
when what happened start A few birds of one species reach a chain of islands middle Each island offers a different food source, and beaks change over generations end There are now five species, each with its own beak Esme reads a case card about model birds. Which word names one founder species giving rise to many species?
- Hybrid zone: an area where two species interact
- Natural selection: inherited traits that help survival become common
- Habitat isolation: groups live in places that no longer overlap
- Adaptive radiation: one founder species gives rise to many species
Leaf types before and after a river splits a population of model plants (model data)
leaf type generation 1 generation 2 east generation 2 west generation 3 east generation 3 west thick 40 30 52 22 65 thin 60 70 48 78 35 Jun reads a table of model plants. A river split the population after generation 1. How many thick-leaved plants are in the west group in generation 3?
- 35
- 22
- 65
- 52
Shell types before and after a new lake splits a population of model snails (model data)
shell generation 1 generation 2 north generation 2 south generation 3 north generation 3 south striped 30 24 38 18 47 plain 70 76 62 82 53 Kira reads a table of model snails that a new lake split into a north group and a south group. Which group has more striped snails in generation 3, and by how many?
- South, by 9
- South, by 47
- North, by 29
- South, by 29
Tail types before and after a barrier splits a population of model mice (model data)
tail generation 1 generation 2 east generation 2 west long 50 44 61 short 50 56 39 Luz reads a table of model mice. It has one column for generation 1 and two columns for generation 2. What does the split in the table show?
- The counts were taken twice by mistake in generation 2
- The two groups became two species at the moment of the split
- A barrier divided one population, so each group is counted on its own
- Half of the mice changed into a new species
Four pairs of model bird groups (model data)
pair how the groups look can they interbreed and have young that can breed? A and B different feather colors yes C and D look alike no E and F different sizes yes G and H look alike yes Milo compares four pairs of model bird groups. Which pair is made of two separate species?
- C and D: they cannot interbreed
- G and H: they look alike
- A and B: their feather colors differ
- E and F: their sizes differ
Looks and species (real facts)
pair how they look species poodle and cocker spaniel differ in size, build and coat one species, since most dogs can interbreed bald eagle and African fish eagle look alike two separate species Noah reads real facts about dogs and eagles. What do the two rows show about looks and species?
- Groups that look alike belong to one species, and groups that look different belong to two
- Groups that look different can be one species, and groups that look alike can be two
- Species are decided by where each group lives, not by how the groups look
- Groups that look different must be separate species, so looks decide the species
Abert and Kaibab squirrels (real facts)
group kind of group where it lives Abert squirrel subspecies of the tassel-eared squirrel pine forest on one side of the Grand Canyon, Arizona Kaibab squirrel subspecies of the tassel-eared squirrel the same kind of forest on the other side Pia reads real facts about two squirrel groups. Which statement about them is right?
- They are one group, since both live in pine forest
- They are two squirrel species, since the canyon separates them
- They are subspecies that live in different kinds of forest
- They are subspecies of one squirrel species, separated by the Grand Canyon
Model plants on the mainland and on an island (model data)
group where it lives how it started mainland group the mainland the original group island group an island a few seeds floated across the ocean Zee reads a table about model plants on the mainland and on an island. What keeps the island group apart from the mainland group?
- Reproductive isolation: the island plants are already a new species
- Geographic isolation: the ocean keeps the groups apart
- Habitat isolation: the groups prefer different kinds of soil
- Seasonal isolation: the groups reproduce in different seasons