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
- Polyploidy: a plant gains extra sets of chromosomes
- Timing isolation: groups reproduce at different times of the year
- Speciation: one species becomes two separate species
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?
- Reproductive isolation: the groups cannot interbreed
- Gene flow: alleles move freely between the groups
- Dispersal: a few members move to a new area
- Mutation: a change in the DNA sequence of a gene
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?
- 65
- 52
- 22
- 35
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
- Half of the mice changed into a new species
- 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
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?
- G and H: they look alike
- C and D: they cannot interbreed
- 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?
- Species are decided by where each group lives, not by how the groups look
- 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
- 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 subspecies that live in different kinds of forest
- They are two squirrel species, since the canyon separates them
- They are one group, since both live in pine forest
- They are subspecies of one squirrel species, separated by the Grand Canyon
Two groups of model rodents after a new lake forms (model data)
group side of the lake moves across the lake? group 1 north no group 2 south no Ren reads a table about model rodents. Which kind of isolation keeps group 1 and group 2 apart?
- No isolation: the groups are still one species, so they mix
- Timing isolation: the groups breed in different months
- Geographic isolation: the lake keeps the groups apart
- Chromosome isolation: the groups have different sets of chromosomes
Flowering months of two model plant groups in one meadow (model data)
group first month last month group X April May group Y July August Tala reads a table about two model plant groups in one meadow. Which kind of isolation does the table show?
- No isolation: both groups share one meadow, so they can interbreed
- Timing isolation: the groups flower in different months
- Chromosome isolation: the groups differ in sets of chromosomes
- Geographic isolation: a barrier splits the groups
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?
- Geographic isolation: the ocean keeps the groups apart
- Reproductive isolation: the island plants are already a new species
- Habitat isolation: the groups prefer different kinds of soil
- Seasonal isolation: the groups reproduce in different seasons
