Mendel and Meiosis and Basic Genetics

Mendel and Meiosis and Basic Genetics

Mendel and Meiosis and Basic Genetics

______is the scientific study of heredity.

Gregor Mendel is called the Father of ______

He worked with ______. He found these plants to be ______. They reproduced quickly, which made them easy to study.

Gregor Mendel developed several of the principles of Genetics

  1. Principle of dominance: Some alleles are dominant and others are recessive.
  1. Principle of Segregation: The 2 alleles are segregated from each other so that each gamete carries only a single copy of each gene.

The principles of probability can be used to predict the outcomes of genetic crosses.

A punnett square is used for predicting probabilities in genetics.

Capital Letters represent ______

Lower case letters represent ______

Homozygous ______


Genotype ______

Phenotype ______

Segregation of gametes is supported by ratios of offspring

Probabilities of offspring predict averages in large sample sizes

Mendels principle of independent assortment states that genes for different traits can segregate independently during the formation of ganetes.

The 2 factor cross demonstrates independent assortment.

R =




Mendel’s principles form the base on which genetics is built

  • The inheritance of characteristics is determined by units known as gene. These are passed from parents to offspring.
  • Some forms of the gene may be dominant and others may be recessive
  • Each adult has 2 copies of each gene—one from each parent, they are segregated from each other when gametes are formed
  • The alleles for different genes usually segregate independently of each other.

Beyond Mendel

Some alleles are neither dominant nor recessive, and many traits are controlled by multiple alleles or multiple genes

Incomplete Dominance:

2 colors mix to make a third color (red + white = pink)


Both colors show up at the same time

Speckles, White body, black feet

holsteins (black and white)

Multiple alleles

More than 2 possible alleles for the same trait

Rabbit coat color

Polygenic traits More than 1 gene determines the trait

Mendel’s principles of genetics require at least two things. First, each organism must inherit a single copy of every gene from both its “______” Because each pea plant has two “______,” each plant must carry two complete sets of genes. Second, when an organism produces its own______, those two sets of genes must be separated from each other so that each gamete contains just one set of genes. This means that when gametes are formed, there must be a process that separates the two sets of genes so that each gamete ends up with just one set.

All body(soma) cells of an organism have the same number of chromosomes

They are paired in ______pairs

This is called the ______number(2n)

Gametes or sex cell have half this Number of chromosomes and are said to be ______(n)

Meiosis is a ______division in which the chromosome number is cut in ______

There are 2 phases of meiosis.

Phase 1 is where ______form and ______can occur

Meiosis II is where the chromosome # is reduced to half

There is NO duplication of chromosomes just a second division of the cells

Gene linkage

Chromosmes sort independently, not ______.

Genes that are on the ______chromosome are inherited together, unless ______happens. The further apart on the chromosome the better the chances of ______happening.

A gene map like below, lets us determine if ______will happen.