Question

1. This is incorrect with respect to a DNA double helix:

	A.	purines pair with purines
	B.	thymine pairs with cytosine
	C.	the two DNA strands run in parallel (both 3' → 5')
	D.	All of the above

2.

1. Which statement is false?

	A.	In prokaryotes, translation occurs in the cytoplasm at the same time as transcription.
	B.	In prokaryotic cells, DNA is not contained in a true nucleus but in a region called the nucleoid.
	C.	Prokaryotic organisms produce monocistronic messenger RNA.
	D.	Some genes in prokaryotes are present in transcriptional units called operons.

3

1. Which of the following eukaryotic organelles originated by endosymbiosis of bacteria?

	A.	Golgi and smooth endoplasmic reticulum
	B.	Rough endoplasmic reticulum and nucleus
	C.	Chloroplasts and mitochondria
	D.	Vacuoles and lysosomes

4.

1. Organelles surrounded by bilipid bilayer membranes are characteristic of eukaryotic cells. Which pair is mismatched?

	A.	Nucleus — Animals, plants, fungi, bacteria
	B.	Mitochondria — Animals, plants, fungi
	C.	Cell wall — Plants, Fungi, bacteria
	D.	Golgi apparatus — Animals, plants, fungi

5.

1. Fill in the blanks. Cells can be very diverse: superficially, they come in various sizes, ranging from bacterial cells such as Lactobacillus, which is a few ___ in length, to larger cells such as a frog?s unfertilized egg, which has a diameter of about one ___.

	A.	nm (10-9 m), μm (10-6 m)
	B.	pm (10-12 m), nm (10-9 m)
	C.	µm (10-6 m), mm (10-3 m)
	D.	mm (10-3 m), cm (10-2 m)

Answer 1