Studied by 5 peopleIndependent assortment
________ helps explain the many genetic variations we see in all living things.
new combinations of alleles
Crossing- over produces ________ on each chromatid.
Environmental conditions
________ can change gene expression and influence genetically controlled traits.
Biological characteristics
________ are inherited through units called genes, which are passed from parents to offspring.
Telophase
________ I and Cytokinesis: Nuclear membranes form and the cell separates into two cells.
F1
When doing genetic crosses, we call each original pair of plants the P, or parental, generation, and their offspring are called the ________ generation.
Interphase
________: Cells undergo a round of DNA replication, forming duplicate chromosomes.
Punnett squares
Use probability to predict combinations of alleles in a genetic cross
Mitosis
________ can be a form of asexual reproduction.
Anaphase I
________: The fibers pull the homologous chromosomes to opposite ends of the cell.
Meiosis
________ makes two identical diploid cells.
Diploid
________ is the term used to refer to a cell that contains two sets of homologous chromosomes.
TT
The tall () plants are homozygous because they have two identical alleles () for a gene; the short plants are also homozygous because they have two identical alleles (________) for a gene.
physical traits
Mendel noticed that all of the tall pea plants had the same phenotype, or ________, but they did not, however, have the same genotype, or genetic makeup.
Alleles
________ for different genes usually segregate independently of each other.
Metaphase I
________: Spindle fibers attach to the chromosomes.
Mendel
________ used garden pea plants in his studies partly because peas are small, easy to grow, can make hundreds of offspring, and have many traits that are easy to see.
zygote undergoes
The ________ cell division by mitosis and grows into an organism.
self pollination
A plant grown from a seed made by ________ has just one parent because both reproductive cells came from the same plant.
Prophase II
________: Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original cell.
Homologous
The term used to refer to chromosomes in which one set comes from the male parent and one set comes from the female parent
gene
A(n) ________ with more than two alleles is said to have multiple alleles.
recessive allele
An organism with a(n) ________ for a form of a trait will show that form only when the dominant allele for the trait is not there.
Mitosis
________ does not change the number of chromosomes.
Meiosis
________ cuts the chromosome number in half.
Chromosomes
________ are made of many genes linked together; gene maps show how far apart these genes are from each other.
Independent assortment
One of Mendel's principles that states that genes for different traits can segregate independently during the formation of gametes
Meiosis
The process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell
Meiosis
________ makes four genetically different haploid cells.
Meiosis
________ is a step in sexual reproduction.
Meiosis
________ involves two rounds of cell division, called ________ I and ________ II.
For example, when flipping a coin, there are only two possible outcomes
the coin can land either heads up or tails up
Although three different combinations of the alleles t and T are possible
Tt, TT, and tt, only two different forms of the plant are possible
Interphase
Cells undergo a round of DNA replication, forming duplicate chromosomes
Prophase I
Each chromosome pairs with its corresponding homologous chromosome to form a tetrad, which has four chromosomes
Metaphase I
Spindle fibers attach to the chromosomes
Anaphase I
The fibers pull the homologous chromosomes to opposite ends of the cell
Telophase I and Cytokinesis
Nuclear membranes form and the cell separates into two cells
Prophase II
Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original cell
Metaphase II
The chromosomes line up in a similar way to the metaphase stage of mitosis
Anaphase II
The sister chromatids separate and move toward opposite ends of the cell
Telophase II and Cytokinesis
Meiosis II results in four haploid daughter cells
Genetics
The scientific study of heredity
Fertilization
The process in sexual reproduction in which male and female reproductive cells join to form a new cell
Trait
A specific characteristic of an individual
Gene
A factor that is passed from parent to offspring
Allele
One of a number of different forms of a gene
Principle of dominance
States that some alleles are dominant and others are recessive
Segregation
The separation of alleles
Gametes
Sex cells
Probability
The likelihood that a particular event will occur
Homozygous
Having two identical alleles for a particular gene
Heterozygous
Having two different alleles for a particular gene
Phenotype
The physical characteristics of an organism
Geneotype
The genetic makeup of an organism
Codominance
A situation in which the phenotypes produced by both alleles are completely expressed
Incomplete dominance
A situation in which one allele is not completely dominant over another allele
Multiple alleles
A gene that has more than two alleles
Polygenic trait
A trait controlled by two or more genes
Diploid
The term used to refer to a cell that contains two sets of homologous chromosomes
Haploid
The term used to refer to a cell that contains only a single set of genes
Crossing-over
The process in which homologous chromosomes exchange portions of their chromatids during meiosis
Zygote
A fertilized egg
Note
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