Download Unit A Topic 3

Science 9|2012
Bly|Dhaliwal
Name: _____________
Date: _____________
Unit A: Topic 3 DNA
3.1 DNA-Transmitter of Genetic Code
1. Offspring of a sexually reproducing species are not _____________________ identical
to their parents.
2. Offspring resemble their parents because particular _____________________ are
passed on from generation to generation.
3. Every multicellular organism on Earth contains a ______________________ for making
a copy of itself in each of the body cells.
4. DNA is short for ________________________________.
5. Canadian scientist Oswald Avery confirmed that DNA was the material of
_____________________.
6. _______________________ and _____________________________ unraveled the
puzzle of the structure of DNA.
7. The arrangement of the four chemicals (G) ________________ , (C) _______________ ,
(A) _______________________ and (T) _________________________ form a code that
cells can read.
8. The __________________________ is based on arranging the four chemical ‘letters’
into instructions that describe how to make a particular organism.
9. DNA contains all the instructions for an organism’s _____________________________.
10. Organisms arrange their DNA into packages called ______________________________.
11. All of our nuclei, except for those in the _______________________, must have a
complete set of chromosomes.
12. In most organisms the chromosomes are arranged into ___________________.
13. Chromosome number ______________ from one species to another.
14. A single gene is an ____________________________________ of DNA, which contains
coded instructions.
15. Researchers found that:
 ____________________________________________________________________
 ____________________________________________________________________
 ____________________________________________________________________
 ____________________________________________________________________
 ____________________________________________________________________
 ____________________________________________________________________
16. Offspring inherit ___________________ from both parents.
17. Most genes exist in an array of possible forms called ___________________ that differ
as to their exact DNA sequence.
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Science 9|2012
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3.2 Cell Division
1. In binary fission, each cell divides __________________________.
2. In order to avoid each new cell having only half of the DNA, the cell must first
_______________________________________________________________________.
3. In multicellular organisms, the process that produces two new cells with the same
number of chromosomes is called _____________________________.
Draw a diagram to illustrate this type of cell division.
Parent cell
makes an exact
copy of its DNA
and each
chromosome
doubles.
The cell divides
and each cell
gets one copy of
the DNA.
4. ________________________ is a type of cell division that produces cells with only half
of the DNA of a normal cell.
Draw a diagram to illustrate this type of cell division.
Parent cell makes an
exact copy of its
DNA and each
chromosome
doubles
First cell division
occurs with the
result of 2 cells.
Second cell division
occurs with the
result of 4 cells with
½ of the
chromosomes of the
parent.
5. Meiosis involves __________ cell divisions to produce only one copy of each
chromosome.
6. Complete the Give it a Try activity on page 48.
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Science 9|2012
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3.3 Patterns of Inheritance
1. Characteristics are called ______________________.
2. The term _______________________________ refers to organisms which have lineages
all with the same form of a trait.
3. A _________________________ results when two individuals breed but they differ in a
trait.
4. A ________________________ trait is the outward form observed when two oppositeacting alleles are inherited.
5. The _______________________ trait appears in the offspring only if two of these alleles
are inherited.
6. _______________________________ occur when neither alleles is truly dominant or
recessive.
7. For hair color, eye color and skin color, many gene ___________________ and several
possible ___________________ may be involved.
8. While genes play a vital role in determining development, the action of the genes is
greatly influenced by the ______________________________ in which the offspring
develops.
9. We have a special chart called a Punnet Square that can help us to predict what trait the
offspring of the parents will have.
Example: Pure dominant male and a hybrid female
D
D
Male Gametes
D
D
DD
DD
Dd
Dd
Hybrid male and hybrid female
Male Gametes
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Science 9|2012
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10. Hamster’s color is represented by the letter, B. B is dominant and represents a brown
hamster; b is recessive and represents a white hamster. For each of the following
situation fill in the punnet square, and predict the number of brown and the number of
white hamsters.
 Cross between a hybrid father and a pure recessive mother.

Cross between a pure dominant father and a hybrid mother.

Cross between a hybrid mother and a hybrid father.

Cross between a pure dominant father and a pure recessive mother.
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