« previous next »

Author Question: The common ancestors of birds and mammals were very early (stem) reptiles, which (Read 951 times)

geoffrey

  • Hero Member
  • *****
  • Posts: 880
on: Jul 14, 2013
The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as
A) structural homologies.
B) vestiges.
C) homoplasies.
D) the result of shared ancestry.
E) molecular homologies.


penguins

  • Hero Member
  • *****
  • Posts: 903
Reply #1 on: Jul 15, 2013
Easy! It's C. Bye for now :D


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question

geoffrey

  • Hero Member
  • *****
  • Posts: 880
Reply #2 on: Jul 15, 2013
Thanks so much, the answer you provide was right on!


« previous next »
 

Did you know?

Patients who have been on total parenteral nutrition for more than a few days may need to have foods gradually reintroduced to give the digestive tract time to start working again.

Did you know?

Only 12 hours after an egg cell is fertilized by a sperm cell, the egg cell starts to divide. As it continues to divide, it moves along the fallopian tube toward the uterus at about 1 inch per day.

Did you know?

Alcohol acts as a diuretic. Eight ounces of water is needed to metabolize just 1 ounce of alcohol.

Did you know?

Computer programs are available that crosscheck a new drug's possible trade name with all other trade names currently available. These programs detect dangerous similarities between names and alert the manufacturer of the drug.

Did you know?

This year, an estimated 1.4 million Americans will have a new or recurrent heart attack.

Common invasive species in the Adelaide Hills: Olive, Artichoke thistle, Fennel and Bamboo Common invasive species in the Adelaide Hills: Olive, Artichoke thistle, Fennel and Bamboo
Primary School Attendance in World Regions Attending primary school is common but not universal, wo Primary School Attendance in World Regions Attending primary school is common but not universal, wo
By age 3, children develop scripts for common events such as eating at a restaurant. By age 3, children develop scripts for common events such as eating at a restaurant.
Examples of the most common X-ray positions and the images they produce. Examples of the most common X-ray positions and the images they produce.
The effect of a few days of early monocular deprivation on the structure of axons projecting from ... The effect of a few days of early monocular deprivation on the structure of axons projecting from ...
Added Sugar in Common Foods Added Sugar in Common Foods
Video: Energy inputs and release in glycolysis Animation

For a complete list of videos, visit our video library