2chapter11

Chapter 11

Introduction to Genetics

Gregor Mendel’s WorkMendel worked with garden peas,

which used parts of their flowers to reproduce by self-pollination.

These peas were true-breeding, meaning that they would produce more peas that would be more identical to themselves.

B.H.

Genes & Dominance Mendel studied the traits of pea plants. Traits are

specific characteristics that determine an individual.

Parents with different traits had hybrid offspring. Mendel came up with two conclusions:

factors that determine biological inheritance, are past from one generation to the next otherwise known as genes.

the principle of dominance shows that some alleles are dominant and others recessive

D.C.

Genetics and Probability Probability is the likelihood that a

particular event will occur.It can predict genetic outcome of

genetic crosses.

B.H

Punnett Squares Gene combinations that form a genetic cross

can be determined by drawing a punnett square.

Organisms with identical alleles are homozygous(true-breeding)

Organisms with different alleles are heterozygous(hybrids)

Phenotypes determine physical characteristics

Genotype determines genetic makeup

D.C

Dominant Alleles

If one allele is not completely dominant over another, its called incomplete dominance.

Organisms with dominant alleles for a particular trait will always have that form.

B.H.

Recessive Alleles

Organisms with recessive alleles will always have that trait only if the dominant allele is eliminated

D.C

Meiosis There are two stages in meiosis; Meiosis I

and Meiosis II. There are also eight phases.

Meiosis is the process of reduction division. The chromosomes in each cell is cut in half.

B.H

Comparing Mitosis & Meiosis

Mitosis is the creation of diploid cells

Meiosis produces haploid cells

D.C

Gene Linkage

Thomas Morgan did research on fruit flies and found that they were linked.

Gene linkage are traits that are inherited together.

Each chromosome is a group of linked genes.

B.H

Gene Maps. Alfred Sturtevant came up with the idea that

the rate of crossing-over separated linked genes.

Gene maps show relative locations of genes on a chromosome.

His idea has been used to construct genetic maps

D.C.

THE END…

BY:BY:Brenda Huynh Brenda Huynh

&& Deanna Deanna

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