Name ______________ Ch 10 Sexual Reproduction and Genetics
10.1 Meiosis Main Idea – Meiosis produces ___________ _________.
1. Human _________ cells have _______ chromosomes
2. Each parent contributes _______ chromosomes, resulting in ___pairs of
chromosomes.
3. The chromosomes that make up a pair, one chromosome from each parent,
are called ______________ ________________.
4. Homologous chromosomes in body cells have the same___________ and
the same ____________ ____________and they carry genes that
____________ the same inherited __________.
5. In order to maintain the same _______________ number from generation
to generation, an organism produces __________, which are sex cells that
have __________the number of chromosomes.
6. In humans each gamete contains _______ chromosomes.
7. A cell with n number of chromosomes is called a ___________ cell.
8. A cell that contains 2n chromosomes is called a _________ cell.
9. Gametes are formed during a process called _________, which is a type of
cell division that _______ the number of chromosomes; therefore, it is
referred to as _________ _________.
10. Meiosis occurs in the __________ structures of organisms that reproduce
_________.
11. Meiosis reduces the chromosome number by ________ through the
______________ of __________________ chromosomes.
12. A cell with ____ number of chromosomes will have gametes with ___
number of chromosomes after meiosis.
13. Meiosis involves ___________ consecutive cell divisions called
_________and_________.
14. Mitosis consists of only ______ set of division phases and produces
_______ identical diploid daughter cells. Meiosis consists of _______ sets of
divisions and produces _______
__________ daughter cells that are ______ _________.
15. Meiosis is important because it results in ____________
_________________.
16. Pairs of homologous chromosomes line up at the _______ during
metaphase I. How the chromosomes line up is a random process that results
in _______ with different ___________ of chromosomes.
17. Depending on how the chromosomes line up at the equator, ______
gametes with _____ different combinations of chromosomes can result.
18. Genetic variation also is produced during_____________ ________ and
_________________, when ____________ randomly combine.
19. During asexual reproduction, the organism inherits ______of its
chromosomes from a ________ parent. The new individual is genetically
________to its parent.
Ch 10.2 Mendelian Genetics pgs. 277-282
Main Idea – Mendel explained how a ___________ allele can mask (hide) the presence of
a ___________ allele.
1.The passing of traits to the next generation is called inheritance, or ____________.
2.Mendel chose to study ________ ___________.
3. True (pure) breeding means that the pea plant consistently __________ with only one
form of a __________.
4. Self-fertilization occurs when a ________ gamete within a flower combines with a
_______ gamete in the same flower.
5. Mendel performed __________ _______________ by transferring a male gamete from
the flower of one pea plant to the female reproductive organ in a flower of another pea
plant.
6. Genetics is the scientific study of _______________.
7. The parent generation is also known as the ____ _______________.
8. The offspring of this P cross are called the first filial (____) generation.
9. The second filial (____) generation is the offspring from the F1 cross.
10. F2 generation plants from these crosses showed a ________ ratio.
11. Mendel studied _______ different traits in the pea plants he bred.
12. Allele - An ____________ form of a ________ _______ passed from generation to
generation. Ex. Pod color in peas – ____________ or _________
13.______________– a form of trait that can mask or hide another form of same trait ex.
in peas the color yellow pod is dominant—represented by capital letter for allele
14.______________ – a form of trait that can be masked or hidden by the dominant form
– ex. in peas the color green pod is recessive—represented by lower case letter
15. An organism with ______ of the ________ alleles for a particular trait
is_______________. (ex. YY, yy or RR, rr)
16. An organism with ______ ___________ alleles for a particular trait
is___________________. (ex. Yy or Rr). When alleles are present in a heterozygous state,
the ___________ trait will be observed.
17. An organism’s __________ __________are called its ____________.
18. The _______________ ___________or outward expression of an allele pair is called
the__________________. An organism’s genotype can’t always be known by its
phenotype.
19. Mendel’s Law of Segregation states that two alleles for each trait ____________ during
meiosis.
20. During______________, two alleles for that trait__________.
21. Heterozygous organisms are called_______________.
22. Monohybrid Cross – Crosses that study a _______ trait. Genotypic ratio 1:2:1
phentoypic ration 3:1
23. Dihybrid Cross – Crosses that study _______ or more traits. These F1 generation
plants are called dihybrids because they are _____________ for each trait.
24. Law of Independent Assortment states that a __________ distribution of ________
occurs during _______ formation. This will result in four possible gametes.
25. Genes on _____________ chromosomes sort __________________ during meiosis
26. Each allele combination is ____________ likely to occur.
27. These results represent a ___________ phenotypic ratio.
28. Punnett Squares predict the ____________ ___________ or results of a cross between
two known genotypes. The gamete types are written along the sides of the Punnett
Square.
Dihybrid Crosses (FOIL method)
P = YYRR
x yyrr (pg. 282)
Phenotype ratio ___________________
P = YyRr
x
YyRr
Phenotype ratio ______________
______________
______________
______________
10.3 Gene Linkage and Polyploidy (pgs. 283-285)
Objectives:
Summarize how the process of meiosis produces genetic variation.
Explain how gene linkage can be used to create chromosome maps.
Analyze why polyploidy is important to the field of agriculture.
Main Idea – The crossing over of linked genes is a source of genetic variation.
1. Genetic Recombination is the new combination of genes are produced by
____________ _________ and ___________________ _________________
2. Combinations of genes due to independent assortment can be calculated using the
formula 2n, where n is the number of_________________ _____________.
Gene Linkage
3._______ that are located close to each other on the same____________ are said to
be ___________ and usually travel together during ________ formation.
4. The linkage of genes on a chromosome results in an exception to Mendel’s law of
independent assortment because _____________ __________ usually do not
____________ ________________.
Chromosome Maps
5. Crossing over occurs more frequently between genes that are ____ _______than
those that are close together.
6. 1st chromosome maps were constructed on data from______ ______ crosses.
7. Chromosome map percentages represent ____________ positions of the genes
8. The___________ the crossover frequency, the farther apart the two genes are.
Polyploidy
1. Polyploidy is the occurrence of ________ or _________ extra _______ of all
chromosomes in an organism.
2. A triploid organism, for instance, would be designated 3n, which means that it has
______ ____________ _______ of chromosomes.
3. Polyploidy ________ occurs in animals. In humans, polyploidy is always ________.
4. Roughly one in three species of known flowering plants are ________. Often, they
have increased _______ and size.