Wich microscope did Anton van Leeuwenhoek use to observe single-cell organisms?

What characteristic of water accounts for its properties of adhesion, cohesion, high specific heat, and nature as a solvent

What are neurotransmitters? What neurotransmitters are associated with depression? Schizophrenia? Pain reduction? Parkinson's disease? Brain arousal? Muscle contractions?

Bernice had leukemia as a child and had to undergo numerous bouts of chemotherapy. The chemotherapy always made her nauseated. During the year of treatment, the waiting room started to make her feel nauseated. The chemotherapy is:

Which molecules are involved in protein synthesis? A) Transfer RNA, introns, and mutagens B) messenger RNA, introns, and Ribosomal RNA C) Ribosomal RNA, transfer RNA, and mutagens D) messenger RNA, Ribosomal RNA and transfer RNA

Special proteins in living organisms that speed up a chemical reaction but aren't destroyed or used up are called

Which of the following do groups of different tissues form? A) organ B) organelle C) organ system D) organism

A gradual change in phenotype over a geographical area is called a?

Which of the following changes in deciduous forests occurs in the winter? a. Trees regain their leaves. b. Trees block the flow of water and nutrients to their leaves. c. The leaves of trees begin to lose their chlorophyll. d.

Which statement about somatic mutations is true

uring which period of prenatal development would exposure to teratogens most likely cause defects to major body structures? a. embryo b. implantation c. fetus d. zygote