Mammals appeared 220 MYA but did not begin to greatly diversify until 65 MYA - why? What will be an ideal response?
During the first 155 MYA of mammalian existence, they shared the Earth with dinosaurs. Mammals
were not able to directly compete, and thus stayed relatively small. After the extinction of the
dinosaurs, mammals evolved to fill the niches previously occupied by the dinosaurs.
You might also like to view...
The primary advantage of gills versus the body surface for gas exchange in aquatic animals is that ________.
A. gills are located near the mouth B. gills have a much greater diffusion surface area C. gills decrease resistance to movement D. all gills contain a countercurrent exchange system
What is genetic diversity? Why is it important to maintain genetic diversity?
What will be an ideal response?
Nematocysts are used for
a. reproduction. b. excretion. c. muscle action. d. circulation. e. defense.
Answer the following questions true (T) or false (F)
1. The number of chromosomes present in a human cell at anaphase of mitosis and anaphase of meiosis II is the same. 2. The number of chromosomes present in a cell in metaphase I and metaphase II is the same. 3. At the end of meiosis I, each of the sister chromatids is considered a full-fledged chromosome.