Ap bio: unit 2 test

Which of the following describes the structure of cilia?

9+2 pattern of microtubule doublets

What is likely to have the greatest concentration of smooth endoplasmic reticulum (SER)?

A cell that makes steroid hormones.

What is a difference between prokaryotic and eukaryotic cells?

Both cells have cytoplasm, but prokaryotic cells lack a nucleus.

Mitochondria are observed in plant cells that contain chloroplasts. Why do you find mitochondria in photosynthetic tissues?

Mitochondria are required to break down sugars and other materials for energy.

Eukaryotic cells contain complex organelles that carry out their chemical reactions. Prokayotes lack many of these complex organelles although they have a variety of unique structures of their own. Most prokaryotic cells can exchange nutrients with the outside environment faster than most eukaryotic cells. Why is this so?

Most prokaryotic cells are smaller and have a higher surface-area-to-volume ratio than eukaryotic cells.

Name and describe the functions of two of the proteins found within the model.

One protein found in the model is integral proteins that transport larger molecules, like glucose. Another protein found in the model is peripheral proteins that bond with other proteins to provide support and structure to the membrane.

How do phospholipids contribute to cell membrane structure?

Phospholipids orient their heads toward the polar molecules and tails in the interior of the membrane, forming a bilayer.

What are the structural and functional similarities and differences between mitochondria and chloroplasts?

Similarities: double membrane, intermembrane space, ATP production, contain DNA. Differences: mitochondria have folds called cristae; chloroplast contains accessory pigments in thylakoids which form grana (stacks) and a stroma.

Which of the following statements describes what happens to the surface area-to-volume ratio of a cell that has the dimensions 1x1x1 um then triples in size to 3x3x3 um?

The SA:V ratio went from 6:1 to 2:1.

A spherical bacterial cell has a radium of 3 um. The human egg cell has a radius of 100 um. Which state correctly indicated the call that is able to more efficiently exchange materials with the external environment and provides a correct explanation?

The bacterial cell because it has the greatest surface area-to-volume ratio.

There is a lower limit to cell size, too. What determines how small a cell can be?

The cell should be able to accommodate all the structures and metabolic activities necessary for survival.

Individuals with an inherited autosomal recessive disorder called primary ciliary dyskenesia (PCD) often have severe respiratory problems due to defective cilian. Males with PCD are often sterile because they produce sperm with defective flagella. Which of the following most likely explains the effect of the recessive allele?

The cells do not produce functional motor proteins in flagella and cilia.

Is the nuclear membrane part of the endomembrane system? Why or why not?

The nuclear membrane is part of the endomembrane system, as it is continuous with the rough endoplasmic reticulum (RER).

Of what are phospholipids important components?

The plasma membrane of animal cells.

Explain why this is called the fluid mosaic model.

There are patterns of proteins and phospholipids form in the plasma membrane that give it the mosaic look. The carbohydrates in the model allow it to be fluid.

Name and describe the importance of the light green structures found inside the membrane (lower left and upper right parts of diagram).

They are glycolipids and carbohyhdrates. Glycolipids help maintain the stability of the plasma membrane and helps in cellular recognition. Carbohydrates form chains and helps in the fluidity of the model and helps recognize other harmful cells.

Organelles such as mitochondria and the endoplasmic reticulum have membranes that compartmentalize reactions and other metabolic processes. To function properly, the organelles must move stubstances across their membranes. Which of the following statements describes a feature shared by mitochondria and the endoplasmic reticulum that increases the efficiency of their basic functions?

They have highly folded membranes.

Which of the following will increase the rate at which glucose enters a cell?

a cell with lots of folds on its surface

The Golgi has a polarity or sidedness to its structure and function. Which of the following statements correctly describes this polarity?

all of these correctly describe polar characteristics of the Golgi function

What is the basic unit of life?

cell

Glycoproteins and glycolipids are important for

cell-to-cell recognition.

What is NOT found in both plant and animal cells?

centrosomes

Which structure is NOT found in prokaryotic cells?

chloroplast

Which of the following could increase the rate at which a cell could exchange nutrients and waste?

divide in half

Where is the largest amount of DNA found in a eukaryotic cell?

in the nucleus

Which organelle is the primary site of ATP synthesis in eukaryotic cells?

mitochondrion

n plant cells, what carries out the function of the lysosomes?

perioxisomes

Which sequence correctly lists in order the steps involved in the incorporation of a protein within a cell membrane?

synthesis of the protein on the ribosome; modification in the ER; tagging in the Golgi; distribution via the vesicle