Chapter 4: The nucleus controls the functions of life

Name: ____________________

In the diagram of the cell, which part refers to the place where hereditary information is stored? ________.

What is the name of this organelle? ____________________.

What is the function of the nucleus?________________________________________________________________________________________________________________________________________________________________________________________________

The nucleus controls the master set of instructions that determines:

1._______________________________________________

2._______________________________________________

3._______________________________________________

4._______________________________________________

Matching: Identify the term that best matches each of the descriptions that follow. Some terms may not be used at all.

a. gene e. traitb. chromosome f. mutagenc. heredity g. mutationd. nucleus

__________ a structure formed from coils of folded DNA

__________ a segment of DNA that codes for a specific protein

__________ the passing on of traits from parents to offspring

__________ a substance that can change DNA

__________ the control centre of a cell

__________ a characteristic of an individual of a species that can be passed on to offspring

__________ is a long, double-stranded molecule that carries the instructions in the nucleus

The sides of the DNA ladder are made of __________________ and __________________.

The steps are made up of four nitrogen bases

1. __________

2. __________

3. __________

4. __________

Modified True/False : Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.

Human body and organ cells each have 23 chromosomes.

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The DNA that directs all cell activities is contained in the cell cytoplasm.

________________________________________________

A section of the DNA molecule that codes for a specific protein is called a chromosome.

________________________________________________________________________________________________

All chromosomes found in a cell are located inside the nucleus of the cell.

________________________________________________________________________________________________

When a cell gets ready to divide, each strand of coiled DNA coils up and forms into a chromosome.

________________________________________________________________________________________________

The number of chromosomes in individuals within the same species will vary.

________________________________________________________________________________________________

Heredity refers to a feature that can vary in size or form from individual to individual.

________________________________________________________________________________________________

A mutagen is a change in the order of chemicals that make up a gene.

________________________________________________________________________________________________

Random changes to DNA are called mutagens.

________________________________________________________________________________________________

What is a mutation?________________________________________________

When a mutation occurs, the bases may be:

1._______________________________________________

2._______________________________________________

3._______________________________________________

What are the 3 effects of a mutation? Give an example of each.

1._______________________________________________

2._______________________________________________

3._______________________________________________

Give an example of a human activity that might result in a mutation?

________________________________________________

What is a mutagen?________________________________________________________________________________________________

Give an example of a mutagen found in nature.

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