S. 2. 3.-Apply concepts underlying Mendel’s law of inheritance

Inheritance

(transmission of characteristics to offspring) refers to the principle regarding how traits are passed on to offspring

Mendel's three Laws of Heredity

This refer to Gregor Mendel's generalizations about how traits are inherited.

Gregor Mendel

This man was a 19th century monk who grew and studied pea plants to determine how their characteristics were passed onto the next generation of plants. By crossing pea plants with different characteristics, he was able to discern patterns in the inheritance of traits

Punnet Square

a square diagram used to determine the various genotype combinations that may be passed from parent to offspring and their likelihood of occurring) to make predictions about the likelihood of a trait being passed from parent to offspring

Traits

One of Mendel's observations was that there are differences in the prevalence of these. This means that some of these are more likely to be passed on than others

Genes

He hypothesized that offspring inherited factors from heir parents. Today we know that Mendel's factors are what

Alleles

Each gene for a trait comes in varieties called these(a specific copy of a gene)

Dominant

the gene for seed color in pea plants has an allele for green and another for yellow. Mendel found that fro two alleles for a gene, this(refers to the most powerful trait or the allele for that trait) trait is always expressed or shown by the organism if it is present

Recessive

(refers to traits that are masked if dominant alleles are also present; also refers to the allele for that trait) allele. This allele is only expressed when both alleles are this- this is Mendel's third law, The Law of Dominance

Mendelian inheritance

inheritance of traits that follow Gregor Mendel's two laws and the principle of dominance

Each Parent

Most living things inherit one of each pair of chromosomes from who

46 chromosomes

each parent contributes 23 chromosomes therefore offspring inherited factors two copies of each gene, one from each parent= . They have two alleles for each gene

Genotype

This combination of two alleles is called this(the genetic makeup of an individual)

Homozygous

If a chromosome contains two alleles that are the same, that genotype is called this(the state of carrying a pair of identical alleles for a gene: AA or aa)

Heterozygous

If a chromosome contains two different alleles, that genotype is called this(the state of carrying different alleles: Aa)

Phenotype

The alleles that are present in an organism determine the this(physical appearance of a trait formed by genetics and environment) of an organism; it's an expression of the genes for that trait. These are visible traits such as seed color and unseen traits such as blood type

Offspring

This express either a dominant or recessive phenotype based on the two alleles inherited for a trait

Inherited traits

These are passed from parents to offspring through gametes(egg/sperm). Each gamete carries 1 chromosome of the chromosome pair(and only one copy of each gene)

Chromosome

human gametes contain 23 chromosomes. When an egg and sperm fuse together(fertilization), a cell with two copies of each of these(and two copies of each gene) results

Zygote

For humans, this contains the 46 chromosomes

Traits

These such as culturally influenced behavior, are not inherited as part of the genome. These are non heritable these not coded for in genes. Mendel's Laws of Heredity focus on inherited these

Punnet square

One way to predict the likelihood of traits in offspring is to use this which can be used to determine the ratios of the genotypes of offspring from a reproductive cross. Genotypes are represented by two letters: capital letters are dominant alleles and lowercase letters are recessive alleles

Dominant allele

When these two parents are crossed, each parent contributes one allele. This pp parent can only contribute a p or recessive allele. All offspring of this cross will have the heterozygous genotype Pp. They will all have the phenotype of purple because they contain what type of allele

75; 25

a cross between two heterozygous flowers: the genotype of the sperm(pollen) from one plant, Pp, is placed at the top of the square. The genotype of an egg(ovules) from another plant, Pp, is placed on the side. These F2 genotypes can then be calculated. The Punnet Square helps us to predict that 25% of offspring will be PP, 50% of offspring will be Pp, and 25% will be pp. this means that it is likely that what% of the offspring will have purple flowers and what% will be homozygous recessive and have white flowers

Haploid gametes

The punnet square results hold true only if parental genes for a trait must segregate or separate equally and randomly into these(sperm/eggs) during meiosis. That way offspring have an equal chance of inheriting either allele

Mendel's Law of Segregation

Offspring inherit one allele from each parent for a trait and no allele is favored or has an advantage over the others. This is what

Dihybrid cross

The inheritance of two traits can also be studied using a Punnet Square. This is called what(a cross between parents heterozygous at two specific genes) and illustrates Mendel's Law of Independent Assortment- it shows that alleles are not inherited together

Meiosis

The gametes that a produced from meiosis are all slightly different from one another and from the starting cell that went through this. No two are identical, and each has a unique combination of genetic material

Crossing over and random assortment of homologous chromosomes

both helps to bring about the shuffling of genetic material during the formation of gametes

Non-Mendelian Inheritance

(inheritance of traits that do not follow Mendelian patterns of inheritance) occurs when there are factors other than dominant and recessive alleles in play

mendelian ratios

These occur when a simple dominant recessive relationship exists between two alleles

Non-Mendelian Inheritance

This results from factors such as multiple alleles(blood groups: A, B, and O), incomplete dominant-recessive relationships that lead to an intermediate(red and white alleles making pink flowers), co-dominance(AB blood group expression both A and B proteins), interaction between genes called epistasis, and when the gene is carried on one of the sex chromosomes, X or Y, differential expression is seen in males(XY) versus females(XX)

Non-Mendelian Inheritance

If 3:1 or 9:3:3:1 relationship is not obtained when the F2 phenotypes are analyzed, it is indicative of non-Mendelian inheritance