bio midterm 1

Given that a newly discovered unicellular organism from acidic mine drainage possesses a cell wall, a plasma membrane, two flagella, and peroxisomes, what is the most likely classification of the organism?

• 1. Nonmotile prokaryote

• 1. Motile bacterium

• 1. Motile archaea

• 1. Nonmotile eukaryote

• 1. Motile eukaryote

A significant decrease in energy production (ATP) in eukaryotic cells would result from the malfunction of which specific organelle?

• 1. Lysosome

• 1. Mitochondrion

• Golgi apparatus

• Peroxisome

Whales can survive cold temperatures partly due to the composition of their membranes. Which of the following characteristics is associated with their membrane structure?

• 1. The membranes have a higher proportion of unsaturated phospholipids.

• 1. The membranes have a lower proportion of cholesterol molecules.

• 1. The membranes have a lower proportion of hydrophobic proteins.

• 1. The membranes have a higher proportion of glycolipids.

Carrot slices that are immersed in fresh water for several hours become firm. Similar slices left in a 0.15 M salt solution become soft. Which statement best explains the tonicity of the surroundings?

• Both fresh water and the salt solution are hypertonic to the cells of the carrot slices.

• 1. Fresh water is hypotonic, and the salt solution is hypertonic to the cells of the carrot slices.

• 1. Fresh water is hypertonic, and the salt solution is hypotonic to the cells of the carrot slices.

• 1. Fresh water is isotonic, and the salt solution is hypertonic to the cells of the carrot slices.

How do saturated fatty acids influence membrane packing and, consequently, membrane fluidity??

• 1. The absence of double bonds allows for a straight structure in the fatty acid tails, promoting tight packing with adjacent lipids.

• 1. Saturated fatty acids have a decreased cholesterol content, facilitating close packing with adjacent lipids.

• 1. Saturated fatty acids are less polar compared to unsaturated fatty acids.

• 1. The absence of double bonds facilitates interaction among the hydrophilic head groups of the lipids.

What's a significant difference between prokaryotic and eukaryotic cells?

• Prokaryotic cells have cell walls, while eukaryotic cells do not.

• 1. Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

• 1. Eukaryotic cells have flagella, while prokaryotic cells do not.

• 1. Prokaryotic cells are generally larger than eukaryotic cells.

What is a defining characteristic of integral membrane proteins among the following options?

• 1. They are hydrophilic.

• 1. They are hydrophobic.

• 1. They are amphipathic, containing at least one hydrophobic region.

• 1. They are situated on the interior surface of the membrane.

Why is 14C considered a radioisotope?

• It has 6 protons, 8 neutrons, and 6 electrons.

• 1. It has 6 protons, 7 neutrons, and 6 electrons.

• 1. It has 8 protons, 6 neutrons, and 8 electrons.

• 1. It has 7 protons, 6 neutrons, and 7 electrons

If you were to design a computer capable of storing information using a biological molecule as its foundation, which molecule would prove to be the most suitable choice?

• 1. DNA

• 1. Carbohydrate

• 1. Chitin

• 1. Saccharide

What propels simple diffusion, and what serves as the energy source for active transport?

• Pressure; ATP hydrolysis

• Temperature; facilitated diffusion

• 1. Concentration gradient; ATP hydrolysis

• 1. Osmotic pressure; facilitated diffusion