Name : ________________
Date : ___________
Unit One - Notes #4 :The Role Of Sexual Reproduction
In Variation And Evolution
A) Important Terms
- Phenotype: Appearance of a trait. Ex. ____________________________
- Genotype: _____________________________________________________________
- Asexual Reproduction: Reproduction that involves only one parent and produces a
new organism that is an exact copy of the parent.
- Diploid: ______________________________________________________________
- Sexual Reproduction: ____________________________________________________
________________________________________________________________________
________________________________________________________________________
- Haploid: One set of each chromosome. (Gametes)
- Mitosis: (Normal Cell Division) Type of cell division in which two daughter cells
receive the exact chromosome and genetic make-up of the parent cell. This occurs
during growth and repair.
- Meiosis: (Reduction division). ____________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________.
IT OCCURS ONLY IN THE
REPRODUCTIVE SYSTEM.
- Cross-over: ____________________________________________________________
________________________________________________________________________
________________________________________________________________________
- Population: A group of members of the _______________________living together
in the same area who can potentially and____________________________________.
B) Role of Sexual Reproduction
Sexual Reproduction 
_____________________
- If there was no sexual reproduction many organisms could still reproduce
asexually, but they would be identical to their parents.
- ______________________________________________________________________
- If mitosis were used instead of meiosis in sexual reproduction there would be too
many chromosomes in the new cells.
Diploid X
2n
Diploid = Tetraploid
2n
4n
(Abnormal)
Example : ______ + ________ = ___________
- ______________________________________________________________________
_______________________________________________________________________
Haploid X
n
Haploid
n
= Diploid
2n
(Normal)
Example : ______ + ______ = _________ ( ___________________)
- ______________________________________________________________________
_______________________________________________________________________
- Meiosis only results in Reshuffling of existing genes. It can only cause organisms
to evolve to some point.
- _________________________ (genes) also play an important role in changing the
____________________ phenotype.