Nucleus - by Skye

NUCLEUS

:~ NATURE & OCCURRENCE ~:

• major, centrally located spherical cellular component.

• bounded by two nuclear membranes; "nuclear envelope".

• nuclear envelope encloses space between 2 nuclear membranes.

• nuclear envelope separates nucleus & cytoplasm.

• encloses nucleoplasm. (thick jelly like fluid in nucleus).

• contains nuclear pores

• nucleopores help in transfer of materials between cytoplasm and nucleoplasm.

(continued...)

• nucleoplasm contains nucleolus and chromatin material.

• nucleolus is rich in RNA. (ribonucleic acid)

• helps in formation of ribosomes

• rich in protein (factory of ribosomes)

Multiple Choice

thick jelly like fluid in nucleus

• cytoplasm

• nucleoplasm

• nucleolus

:~ CHROMATIN MATERIAL ~:

• thin, thread like mass of chromosome material

• composed of genetic material DNA (deoxyribonucleic acid) and proteins.

• formed by nucleosomes, each with a DNA molecule coiled around .

• DNA stores info for the cell to function, to grow, to reproduce

• distinct segments of DNA are called "genes"

• chromatin condenses and forms a thick ribbon like chromosome during cell division.

:~ FUNCTION OF NUCLEUS ~:

• controls all metabolic activities in a cell

• regulates the cell cycle

• transmits hereditary traits

Multiple Choice

Chromatin _____ to form chromosomes

• evaporater

• condenses

• freezes

• sublimates

Multiple Choice

Which of the following is not a function of nucleus?

• removes worn out and poorly working cellular organs

• control metabolic activities in a cell

• regulation of cell cycle

Study this diagram carefully and memorize each part of the nucleus properly. Next questions will be based upon this diagram.

Multiple Choice

Which part is also known as "factory of ribosomes" ?

• 1

• 2

• 3

• 4

• 5

Multiple Choice

Name part 4

• Nucleoplasm

• Nucleolus

• Nuclear pores

Multiple Choice

Chromatin material is a thread like structure composed of DNA. Which part from the previous diagram correctly identifies the chromatin material?

• 1

• 2

• 3

• 4

• 5

Here is the labeled diagram of nucleus :)

That's it for "nucleus" !! Hope this helped you. Thank you :)

Check out my other lessons and fun quizzes........Byeee!!!!!

-Skye C

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