Test 2 Biology: Speciation 2

Front 1

What mechanisms prevent mating between species?

Back 1

Pre-zygotic reproductive barriers prevent mating or fertilization.

Post-zygotic (occurs after the egg has been fertilized) reproductive barriers prevent embryo or fetus development, or result in infertile offpsring.

Front 2

What are pre-zygotic reproductive barriers?

Back 2

Pre-zygotic reproductive barriers prevent mating or fertilization.

Front 3

What are post-zygotic reproductive barriers?

Back 3

Post-zygotic (occurs after the egg has been fertilized and the zygote has been formed) reproductive barriers prevent embryo development or fetus development or result in infertile offspring.

Front 4

Which mechanism is more common?

Back 4

Data shows that pre-zygotic mechanisms are more common.

Front 5

Explain pre-zygotic reproductive isolation due to habitat isolation.

Back 5

Habitat isolation:

There is no physical contact among two or more species that inhabit the same area since they favor different habitats.

Front 6

Explain pre-zygotic reproductive isolation due to temporal isolation.

Back 6

Temporal isolation:

Each species reproduces during different times of the day, different seasons, or different years.

Front 7

Explain pre-zygotic reproductive isolation due to behavioral isolation.

Back 7

Behavioral isolation:

Different species have incompatible courtship and mating rituals that prevent mate recognition.

They perform different forms of behavior that allow their own kind to identify them.

Front 8

Explain pre-zygotic reproductive isolation due to mechanical isolation.

Back 8

Mechanical isolation:

Anatomical differences (structrual incompatibility) prevent mating between different species.

Front 9

Explain pre-zygotic reproductive isolation due to gametic isolation.

Back 9

Gametic isolation:

Foreign sperm cannot recognize the egg.
Foreign sperm cannot penetrate the egg.
Foreign sperm cannot survive in the female reproductive tract.

Front 10

What is the speciation gene in mice?

Back 10

PRDM9

Male hybrids inherit two incompatible alleles at the PRDM9 gene that disrupt the sperm formation resulting in sterility.

Front 11

How can mutations lead to speciation?

Back 11

Mutations in genes that control the rate, pattern, or time of development can alter phenotype and lead to speciation.