Question

1. Although most marine algae species are single-cell (unicellular), they are classified as members of the Domain Eukarya. What specific internal structures must algae cells possess in order to be considered eukaryotic?

2. Two domains include bacteria-like organisms, Archaea and Bacteria. What characteristics are common to these domains? How are they different?

I. Two Similarities:

II. Two Differences:

3. Place the words in the following word bank in the category where they belong: hypothesis or scientific theory

Word Bank: Confirmed – Thoroughly tested – Specific event – Needs testing – Broad explanation – Supported by evidence – Tentative explanation

            Hypothesis Category:                                                                                                                

            Scientific Theory Category:

Answer 1

1. Answer- Algae are eukaryotic organism the first and most important criteria for separation of algae from prokaryotes is the presence of a well defined nucleus in their cells. Because prokaryotes are characterized by absence of a well defined nucleus without nuclear membrane their genetic material lies freely in the cytoplasm and is called nucleoid. While algal cell contains well defined nucleus.

Moreover prokaryotes do not have membrane bound organelle is as mitochondria or chloroplast but algae contains such algae contains such organelles.

2. Answer- Similarities between bacteria and archaea-

• Both are prokaryotic organisms and did not have well defined nucleus.
• Both groups have cell wall and uses flagella to swim.

Differences between bacteria and archaea-

• Cell wall of bacteria is made up of peptidoglycan while cell wall of archaea is made up of pseudopeptidoglycan.
• Archaea do not follow the glycolysis and krebs cycle wile bacteria follows glycolysis and krebs cycle.
• Archaea are non pathogens while some bacteria are pathogens.

3. Answer-

Hypothesis-

Is an unproven statement or a mere assumption to be proved or disproved, about a factor, on which the researcher is interested, is called a hypothesis. It is a tentative statement, which is concerned with the relationship between two or more phenomena, as specified by the theoretical framework. The hypothesis has to go through a test, to determine its validity.

Scientific theory-

It is an idea or a broad range of ideas that are assumed to be true, which aims at explaining cause and effect relationship between multiple observed phenomena. It is based on hypothesis, which after a thorough analysis and continuous testing and confirmation through observation and experiments, becomes a theory. As it is backed by evidence, it is scientifically proven.

Therefore words are to be placed as-

Hypothesis category: needs testing and tentative explanation.

Scientific theory category: thoroughly tested, supported by evidence, broad explanation of a scientific phenomenon.

The term specific event can be placed in either or both category because is a scientific theory or a hypothesis can be placed at specific event when scientists get together.