Q: Answer the following question given this paragraph: Carl Woese and the Phylogenetic Tree In the past, biologists grouped living organisms into five kingdoms: animals, plants, fungi, protists, and bacteria. The organizational scheme was based mainly on physical features, as opposed to physiology, biochemistry, or molecular biology, all of which are used by modern systematics. The pioneering work of American microbiologist Carl Woese in the early 1970s has shown, however, that life on Earth has evolved along three lineages, now called domainsBacteria, Archaea, and Eukarya. The first two are prokaryotic cells with microbes that lack membrane-enclosed nuclei and organelles. The third domain contains the eukaryotes and includes unicellular microorganisms together with the four original kingdoms (excluding bacteria). Woese defined Archaea as a new domain, and this resulted in a new taxonomic tree (Figure 1.17). Many organisms belonging to the Archaea domain live under extreme conditions and are called extremophiles. To construct his tree, Woese used genetic relationships rather than similarities based on morphology (shape). Woese's tree was constructed from comparative sequencing of the genes that are universally distributed, present in every organism, and conserved (meaning that these genes have remained essentially unchanged throughout evolution). Woese's approach was revolutionary because comparisons of physical features are insufficient to differentiate between the prokaryotes that appear fairly similar in spite of their tremendous biochemical diversity and genetic variability (Figure 1.18). The comparison of homologous DNA and RNA sequences provided Woese with a sensitive device that revealed the extensive variability of prokaryotes, and which justified the separation of the prokaryotes into two domains: bacteria and archaea. Q: In the past, biologists grouped living organisms into five kingdoms: animals, plants, fungi, protists, and what? A:

OPTIONS:
- trees
- pathogens
- lizards
- bacteria

A: bacteria

Q: Answer the following question given this paragraph: Prenatal diagnosis refers to the diagnosis of a disease or condition before the baby is born. Q: What type of diagnosis happens before a baby is born? A:

OPTIONS:
- maternal
- fetal
- postnatal
- prenatal

A: prenatal

Q: Answer the following question given this paragraph: Q: What is another name for trisomy 21? A:

OPTIONS:
- cystic fibrosis
- Tay-Sachs Disease
- Fragile X
- down syndrome

A: down syndrome

Q: Answer the following question given this paragraph: Unsaturated hydrocarbons contain at least one double or triple bond between carbon atoms. As a result, the carbon atoms are unable to bond with as many hydrogen atoms as they would if they were joined only by single bonds. This makes them unsaturated with hydrogen. Unsaturated hydrocarbons are classified on the basis of their bonds as alkenes, alkynes, or aromatic hydrocarbons. Q: What type of hydrocarbons contain at least one double or triple bond between carbon atoms? A:

OPTIONS:
- ionic
- catalytic
- saturated
- unsaturated

A:
unsaturated