3/6 - Ext Ticket Embryology

A change in the inherited characteristics of an organism over time is ________

• evolution.
• development.
• growth.
• ancestry.

Another word for specific parts that form an organ, system, or living thing is __________.

• structure.
• vertebrae.
• forelimb.
• organism.

_____________  is the study of embryos to see how their similarities and differences indicate an evolutionary relationship.

• Paleontology
• Common ancestry
• Homologous structure
• Embryology

The most recent ancestral form or species from which two different species evolved is known as ________________________.

• a common ancestor.
• an embryonic stage.
• development.
• evolution.

In stage 2 (middle row) fish embryos _________

• are very different bird and mammal embryos.
• are still very similar to bird and mammal embryos.
• show arm and leg buds.
• are the only embryos with tails.

In the the third embryonic stage (bottom row), mammal embryos _____

• have more characteristics in common with each other than with reptiles or birds.
• are still hard to tell from reptiles and birds.
• have the same features as fish, reptiles, and birds.
• do not have tails.

Ostrich wings are examples of

• homologous structures
• vestigial structures
• adaptations
• traits

Why do embryologist study embryos?

• to see if they are related
• to understand adaptations
• to determine the age
• to learn what parents are vestigial

Natural selection is

• survival of the fittest
• humans change
• two species are the same
• more animals survive

This makes an organism more suited to its enviornment

• species
• lifespan
• adaptation
• mutation