Chapter 11 Flashcards
Cross polynation
Reproduction of one plant with another plant
Hybrids
The offspring of crosses between parents with different traits
Cross pollination is allowing…
One plant to reproduce with another
Mendel prevented self pollination by
Snipping off anther and filament (Male parts) (Polen = sperm)
Parent =
Filial =
P1
F1
Principal of dominance
Some alleles are dominant and others are recessive
An individuals characteristics are determined by factors that are passed from one parental generation to the next. Today we call those factors
Genes
Alleles
Different forms of a gene
A single gene has two contrasting varieties
Gene =
Allele =
Height
Short or tall
Laws of segregation (2)
- Organisms inherit 2 copies of each gene, one form each parent
- Organisms donate only one copy of eac gene, thus 2 copies of each gene segregate or separate during meiosis
Each gamete only donates
One allele for each gene
Phenotype
Physical traits (tall, short, round, wrinkled)
Genotype
Genetic make up or type of alleles
The genotype is inherited and the phenotype is determined
Primarily by the genotype
Independent assortment
Genes for different traits can segregate independently during gamete formation
Incomplete dominance
Red flower (RR) and white flower (WW) end result pink flower
Codominance
Red flower and white flower make white and red flower
A trait is a…
Specific characteristic such as color or height. Pea plants have 7 traits
Traits controlled by two or more genes are said to be
Polygenic traits
A process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell
MEIOSIS
At the end of prophase 1 a spindle forms and attaches to each
Tetrad - trade (crossing over of) alleles
A pairing of chromosomes creates a structure called a
Tetrad.
A tetrad contains 4 chromatids
Metaphase - homologous chromosomes…
Line up across the center of the cell
Anaphase 1
Spindle fibers pull each homologous chromosome pair toward opposite ends of the cell
Telophase
A nuclear membrane forms around each cluster of chromosomes
Meiosis 1 results
Results in 2 daughter cells. The two cells that have been produced by Meiosis 1 have sets of chromosomes and alleles that are different from each other and from the diploid cell that entered meiosis 1
Meiosis 2
Neither cell goes through a round of chromosome replication
What is the main difference between haploid and diploid cells?
The number of chromosome sets found in the nucleus
Diploid
A cell with two complete and identical chromosome sets
Haploid
These are cels with only one chromosome set
Result of Meiosis 2
The result is 4 Haploid daughter cells
At the end of mitosis, you get two daughter cells with..
The same amount of DNA or chromosomes as the parent cells called diploid cells - represented by 2n
At the end of meiosis, you get
4 daughter cells, half the chromosomes, haploid cells
Genetic linkage
The tendency of all alleles of different genes that are closely together on a chromosome to be inherited together during the meiosis phase of sexual reproduction
