Biology Unit 1

Bacteria are grouped as either gram‑positive or gram‑negative. Which features are found in gram‑positive bacteria, and which are found in gram‑negative bacteria? Gram Positive Bacteria:

-Have thick cell walls -Have no membrane on outside walls -All found in one phylum

A cell uses many methods to transport solutes across the plasma membrane. Classify the descriptions as either simple diffusion, facilitated diffusion, active transport, or bulk transport.

Simple diffusion - movement of solutes into the cell directly through the plasma membraneFacilitated diffusion - movement of solutes into the cell down their concentration gradient using membrane proteinsActive transport - movement of solutes into the cell against their concentration gradient using membrane proteinsBulk transport - movement of contents of transport vesicles into the cell by endocytosis

Which statements are properties of protein‑based active transport?

Substances move from an area of lower concentration to an area of higher concentration; Substances cross the plasma membrane by being pumped through a protein using ATPATP .

Bacteria are grouped as either gram‑positive or gram‑negative. Which features are found in gram‑positive bacteria, and which are found in gram‑negative bacteria? Gram Negative Bacteria

-Have thin cell walls -have membranes of lipoproteins and lipopolysaccharides on the outer side of cell walls -Found in many phyla

Cells are categorized as either prokaryotic or eukaryotic. Classify the characteristics as being unique to prokaryotic cells, common to both cell types, or unique to eukaryotic cells. Move each description into the correct category.

Prokaryotic: -Relatively small- Lack membrane-bound organelles Both:- Contain DNA- Use ribosomes to synthesize proteins- Have cytoplasm Eukaryotic:- Complete copy of DNA stored in multiple chromosomes

Which of the statements are true of endosymbiotic theory?

explains why chloroplasts contain a double membrane; explains the origin of some eukaryotic organelles, such as mitochondria; states that an ancestral eukaryotic cell engulfed a photosynthetic protobacteria