As scientists began investigating living things and their cellular structure, they developed a set of principles that are now known as the cell theory. The statements below summarize cell theory.

• All living things are made up of cells.
• Cells are the basic units of structure and function in living things.
• New cells are produced from existing cells.

What was the role of microscopes in the development of cell theory?

A. Cell theory relied on the invention and improvements in the light microscope, which allowed scientists to identify cells.
B. Cell theory relied on the invention of electron microscopes, which allowed scientists to identify and describe cellular structures.
C. Cell theory was developed independently of microscopes, but scientists today use microscopes to confirm the theory.
D. Cell theory is unrelated to microscopes because cells can be observed and studied with the unaided eye.

The diagram shows a fossil of an ancient whale skull and a skull of a present-day whale. the ancient whale is extinct and is believed to be an ancestor of the present-day whale. what do these skulls most likely show that supports darwin’s theory of evolution? all populations can adapt and survive. only some organisms have a common ancestor. populations change slowly over time. populations rapidly become extinct.

In a hypothetical breed of dogs, coat color is controlled by two genes. there are six different coat colors in this breed: black, brown, cream, gray, silver, and tan. consider the following crosses. cross 1: black females from a lineage of all black dogs are crossed with brown males from a lineage of all brown dogs. f1 males and females are all black. when f1 are intercrossed, f2 males and females are black or brown. cross 2: black females from a lineage of all black dogs are crossed with tan males from a lineage where all males are tan and all females are cream. f1 males are black, f1 females are gray. when f1 are intercrossed, f2 males and females are black, brown, gray, or tan. cross 3: silver females from a lineage where all females are silver and all males are gray are crossed with brown males from a lineage of all brown dogs. f1 males and females are all gray. when f1 are intercrossed, f2 males are black, brown, gray, or tan, f2 females are cream, gray, silver, or tan. select the correct statements regarding the mode of inheritance of the coat color genes. a) both genes are x-linked. b) both genes are autosomal. c) one of the genes modifies the expression of the other gene. d) each gene has an additive effect on the intensity of coat color. e) each gene independently specifies three colors. f) one of the genes is autosomal, and the other is x-linked.

Development has provided electrically for less money but what may be considered a cause of nuclear power