What percentage of animals on earth are vertebrates

a. 5

b. 25

c. 50

d. 90

Between the right ventricle and the left atrium blood goes through the lungs. based on the data you have collected, what happens in then lungs

Do flower bulbs bloom faster in the refrigerator or in the warm room

A plant grows in soil contaminated with toxins. Through which structure word the toxins first enter the plant? A. Paramecium B. Chloroplasts C. Phloem D. Xylem

How are the carbon, oxygen, and nitrogen cycles vital to sustaining life on Earth? a. Carbon, oxygen, and nitrogen are vital components of life on Earth. b.

Baby sea turtles hatch underground, automatically dig upward towards the sky, and scurry towards the waves. this is an example of what behavior

Tightly curled hair is caused by a dominant autosomal gene in humans. This trait is rare among northern Europeans.

The rapid depolarization phase of the action potentials of myocardial contractile cells is due primarily to which ion (s) ?

Echinoderm reproduction typically is a. sexual reproduction by budding. b. sexual reproduction with internal fertilization. c. by regeneraton. d. sexual reproduction with external fertilization.

Which is an abiotic factor of the boomslang's environment? A. the sun B. the tree C. the grass D. the people

A double-stranded molecule of DNA has 80 T nucleotides and 110 G nucleotides. What is the TOTAL number of nucleotides in this molecule of DNA?