Ch.5 - Biological MoleculesWorksheetSee all chapters
All Chapters
Ch.1 - Introduction to Biology
Ch.2 - Chemistry
Ch.3 - Water
Ch.4 - Carbon
Ch.5 - Biological Molecules
Ch.6 - Cells
Ch.7 - The Membrane
Ch.8 - Energy and Metabolism
Ch.9 - Respiration
Ch.10 - Photosynthesis
Ch.11 - Cell Signaling
Ch.12 - Cell Division
Ch.13 - Meiosis
Ch.14 - Mendelian Genetics
Ch.15 - Chromosomal Theory of Inheritance
Ch.16 - DNA Synthesis
Ch.17 - Gene Expression
Ch.18 - Regulation of Expression
Ch.19 - Viruses
Ch.20 - Biotechnology
Ch.21 - Genomics
Ch.22 - Development
Ch.23 - Evolution by Natural Selection
Ch.24 - Evolution of Populations
Ch.25 - Speciation
Ch.26 - History of Life on Earth
Ch.27 - Phylogeny
Ch.28 - Prokaryotes
Ch.29 - Protists
Ch.30 - Plants
Ch.31 - Fungi
Ch.32 - Overview of Animals
Ch.33 - Invertebrates
Ch.34 - Vertebrates
Ch.35 - Plant Anatomy
Ch.36 - Vascular Plant Transport
Ch.37 - Soil
Ch.38 - Plant Reproduction
Ch.39 - Plant Sensation and Response
Ch.40 - Animal Form and Function
Ch.41 - Digestive System
Ch.42 - Circulatory System
Ch.43 - Immune System
Ch.44 - Osmoregulation and Excretion
Ch.45 - Endocrine System
Ch.46 - Animal Reproduction
Ch.47 - Nervous System
Ch.48 - Sensory Systems
Ch.49 - Muscle Systems
Ch.50 - Ecology
Ch.51 - Animal Behavior
Ch.52 - Population Ecology
Ch.53 - Community Ecology
Ch.54 - Ecosystems
Ch.55 - Conservation Biology
Sections
Polymers
Carbohydrates
Proteins
Nucleic Acids
Lipids
Additional Practice
Cumulative Macromolecules

Solution: The base compositions of samples of genomic DNA from several different animals were given below. Which samples are likely to come from the same species? HINT: You should be able to identify 2 species

Problem

The base compositions of samples of genomic DNA from several different animals were given below. Which samples are likely to come from the same species? HINT: You should be able to identify 2 species (i.e. 2 pairs of samples) from the given data. Assume that only A, T G, and C are present in the DNA samples.

A. 27.3% T

B. 29.5% G

C. 13.1% C

D. 36.9% A

E. 22.7% C

F. 19.9% T

Solution

Deoxyribonucleic acid (DNA) is a polymer of nucleotides with deoxyribose as their sugar. Aside from its sugar, nucleotides are also composed of a nitrogenous base and an inorganic phosphate group. The nitrogenous baases of these polymers may be the purines, adenine (A), and guanine (G), or the pyrimidines, cytosine (C), and thymine (T). DNA is widely known to be used as storage of genetic material. Relatively large multicelluar organisms, such as animals have DNA in the form of a double-stranded helix. The double-stranded form of DNA is made through a purine-pyrimidine complementary base pairing: A pairs with T and G pairs with C. Thus, a double-stranded DNA will have equal number of As and Ts, and equal number of Gs and Cs.

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