biology- chapter 11
Anaphase II
Chromatids separate
Metaphase II
Chromosomes line up along equator, not in homologous pairs
Prophase I
Crossing-over occurs with tetrads
Telophase/cytokinesis I
Cytoplasm divides, 2 daughter cells are formed
Metaphase I
Homologous chromosomes line up along equator
Prophase I
Homologous chromosomes pair up and form tetrad
Telophase/cytokinesis II
Nuclear membrane reforms, cytoplasm divides, 4 daughter cells formed
Codominance
One allele is not completely dominant over another allele but both alleles show up in the phenotype
Incomplete Dominance
One allele is not completely dominant over another allele; neither one shows up in the phenotype on their own but they blend
Multiple Alleles
One gene for a trait has more than two alleles
Polygenic Traits
One trait is controlled by more than one gene
Anaphase I
Spindle fibers move homologous chromosomes to opposite sides
No (If a homozygous dominant organism is crossed with a homozygous recessive organism, all the F1 generation will be heterozygous and will all show the dominant trait (so the recessive trait will not appear in that generation). If the F1 generation is crossed, the F2 generation will show 1 homozygous dominant, 2 heterozygous, and 1 homozygous recessive—so the recessive traits shows up again.)
do all phenotypes (traits) show up in every generation?
Black & white speckled chickens
example of codominance?
Four o'clock flowers
example of incomplete dominance?
Coat color in rabbits, blood type in humans
example of multiple alleles?
Skin color in humans
example of polygenic traits?
co-dominance=they both show, incomplete dominance=they blend
explain the difference between co-dominance and incomplete dominance
linked gene
genes for certain traits are almost always inherited together and only rarely become separated from each other; they are located close together on the same chromosome
can be seen when observing an organism
how can you determine someone's phenotype?
heterozygous
if an offspring was to inherit the alleles Dd, what would you call its genotype?
crossing over
this process is called?
prophase of meiosis 1
this process occurs during what phase in what process?
chromosomes that contain the same genes
what are homologous chromosomes?
MmRr X MmRr
what are the genotypes of the parents?
Traits are passed down from parents to offspring
what did gregor mendel discover in his experiments with pea plants?
frequency of crossing over between genes
what frequency is looked at to determine the location of genes on a chromosome?
the physical characteristics of an organism
what is a phenotype?
first generation offspring from crossing the P generation
what is the F1 generation?
second generation offspring from crossing the F1 generation
what is the F2 generation?
parent generation
what is the P generation?
3 tall : 1 short
what is the phenotypic ratio?
9:3:3:1
what is the phenotypic ratio?
dominant
what phenotype will show in a heterozygous (Bb) genotype?
dominant
what phenotype will show in a homozygous dominant (BB) genotype?
recessive
what phenotype will show in a homozygous recessive (bb) gemotype?
9:3:3:1
what phenotypic ratio will you always get when you cross two traits of two organisms that both have heterozygous genotypes for both traits?
principle of Independent Assortment
what principle did Mendel use to explain the results of his dihybrid cross?
Principle of Segregation
what principle did mendel come up with when he examined the F2 generation?
multiple alleles
what type of inheritance controls the human traits of eye color?
polygenic
what type of inheritance controls the human traits of skin color?
same chromosome
where are linked genes located?
