The Nucleus

Do Now:

1. Take out last night’s homework

The nucleus is a small sphere that holds all of a cell’s DNA.

Structure & Function

• Structure: spherical lipid membrane (like cell membrane)

• Function: Stores DNA, controls cell activity

It is found ONLY in EUKARYOTIC cells.

Dolly the SheepDolly was the first clone of an adult mammal ever made.

Dolly was born in 1997, she died a few years later, younger than usual for a sheep.

So what does a cloned sheep have to do with a cell nucleus?

When adult animals are cloned, it is by adding a nucleus

from a cell to a new egg cell without a nucleus.

How to Make a Sheep.

The nucleus is surrounded by a lipid membrane called the

nuclear envelope, which is very similar

to the cell membrane. It has

openings called nuclear pores that allow things in and out of the nucleus.

Most of the inside of a nucleus is made up of chromatin, which is a mix of DNA and certain proteins.

The nucleolus is a small dark part inside a nucleus where ribosomes are

made.

Find those parts:

Nuclear Envelope

Nuclear Pores

Chromatin

Nucleolus

Homework… read all about it!

• “Nucleus” p. 81 , SR #3 p. 83

Cell City!

• You will be constructing a project during this unit.

• You will construct a city that is an analogy to a cell.

• Each part of the city should have a similar function to one of the cell parts we study.

• You will get more information soon, but start thinking: what part of a city is a cell membrane like? A nucleus?