Cell Structure and Function

Play an AI-generated podcast conversation about this lesson

What is the main function of the cell surface membrane?

to control the exchange of materials between the cell and its environment

What is the nucleus and where is it found?

a relatively large structure that is found in all eukaryotic cells

What is the difference between the cell surface membrane and the nuclear envelope?

the cell surface membrane surrounds the entire cell, while the nuclear envelope surrounds the nucleus

What is unique about the structure of the cell surface membrane?

it is partially permeable Signup and view all the answers

What is the diameter of the cell surface membrane?

about 7 nm Signup and view all the answers

What is the main difference between the structures found in animal and plant cells?

plant cells have additional structures not found in animal cells Signup and view all the answers

What is the term for all the living material outside the nucleus?

cytoplasm Signup and view all the answers

What is the definition of an organelle?

a functionally and structurally distinct part of a cell Signup and view all the answers

What is the main function of nucleoli?

to make ribosomes Signup and view all the answers

What is the term for the material of which chromosomes are made?

chromatin Signup and view all the answers

Why is it essential to organize cell activities in separate compartments?

for a structure as complex as an animal or plant cell to work efficiently Signup and view all the answers

What is the term for the combination of cytoplasm and nucleus?

protoplasm Signup and view all the answers

What is the minimum distance between two points that can be distinguished as separate using a light microscope?

200 nm Signup and view all the answers

Why does increasing the magnification of an image not reveal more detail?

Because the resolution remains the same, and increasing magnification only makes the image more blurred. Signup and view all the answers

What is the purpose of adding a drop of glycerine to the stain in the preparation of biological specimens?

To help prevent the specimen from drying out Signup and view all the answers

What is the purpose of the equation actual size, A = image size, I / magnification, M?

To calculate the actual length of an object from its magnified image. Signup and view all the answers

What is the effect of methylene blue on animal cells such as cheek cells?

It stains the cells Signup and view all the answers

What is the significance of the wavelength of 700 nm in the electromagnetic spectrum?

It corresponds to red light. Signup and view all the answers

What happens when two points are closer together than the resolution of a microscope?

They cannot be distinguished as separate. Signup and view all the answers

What is the purpose of using a cover slip in the preparation of biological specimens?

To protect the microscope lens and prevent the specimen from drying out Signup and view all the answers

What is the effect of iodine in potassium iodide solution on plant specimens?

It stains starch blue Signup and view all the answers

What is the advantage of using an electron micrograph, such as Figure 1.20, over a light microscope?

It can resolve smaller details, allowing for a higher resolution. Signup and view all the answers

Why are temporary preparations of fresh material useful in biology?

For quick preliminary investigations Signup and view all the answers

What is the purpose of macerating (chopping up) material in biology?

To examine the internal structure of the material, such as wood (xylem) Signup and view all the answers

What is the purpose of the spindle made of microtubules during nuclear division?

The spindle is used for the separation of chromatids or chromosomes. Signup and view all the answers

What is the difference between the size of cytoplasmic ribosomes and those found in mitochondria and chloroplasts?

Cytoplasmic ribosomes are 80S, while those of mitochondria and chloroplasts are 70S. Signup and view all the answers

What is the endosymbiont theory, and what does it suggest about the origin of mitochondria and chloroplasts?

The endosymbiont theory suggests that mitochondria and chloroplasts are, in effect, ancient bacteria that now live inside the larger cells of animals and plants. Signup and view all the answers

What is the role of the DNA and ribosomes found in mitochondria and chloroplasts?

The DNA and ribosomes are responsible for the coding and synthesis of certain vital proteins. Signup and view all the answers

What is the significance of the discovery of ribosomes in mitochondria and chloroplasts?

The discovery of ribosomes in mitochondria and chloroplasts suggests a similarity with bacterial ribosomes. Signup and view all the answers

What is the function of the mitochondrial matrix in relation to ribosomes?

The mitochondrial matrix is where the mitochondrial ribosomes are found. Signup and view all the answers