Q: Coral reefs and tropical rainforests are ecosystems known for what, contributing greatly to the species in existence on earth? Choices: - commensalism - mass migrations - spontaneous mutation - biodiversity A:
biodiversity

(Question)
Q: What is the study of the vital statistics of populations and how they change over time? Choices: - sociology - ethnography - anthropology - demography A:
(Answer)
demography

Ques: Q: Elements below the second period, such as silicon, do not form what as readily as second-period elements, and when they do form, they are weaker than those formed by second-period elements? Choices: - covalent bonds - magnetic bonds - k. bonds - n bonds A:
Ans: n bonds

(Q).
Q: What is a segment of dna that carries a code for making a specific polypeptide chain called? Choices: - a protein - nucleotide - amino acid - a gene A:
(A).
a gene

Ques:Q: What is responsible for the physical changes of puberty? Choices: - nicotine - caffeine - adrenaline - testosterone A:

Ans:testosterone

Question: Q: What shape is the colony of a volvox cell? Choices: - pyramid - coil-shaped - tubular - hollow ball shaped A:
Answer:
hollow ball shaped