Anchor Summary
The combination of alleles in an organism’s cells is its genotype. Remember that a gamete contains only one chromosome of each pair. But therefore it contains one o f the two alleles making up the organism's genotype.
Punnett squares show the probability that each offspring will have a given genotype. A pedigree chart can be used to trace inheritance of a trait through multiple generations of related individuals. Not all genes have one dominant and one recessive allele.
Alleles show codominance meaning that heterozygotes express both the dominant and recessive phenotypes rather than a blend of the two. Some genes have more than two possible alleles. In humans and many other animals have a single pair of chromosomes called sex chromosomes that determines an individual sec. Human sex chromosomes are the X chromosomes and the Y chromosome. An XX individual is female while XY individual is male. The X chromosome is much larger than Y.
Hemophilia, a blood clotting disorder and is determined by a single gene on the X chromosome. A father with hemophilia will pass the recessive allele to all of his daughters. Assuming that the mother is homozygous dominant the daughters will be carriers of disorders.
Essential Questions
What is genetics?
Why is understanding genetics important for scientist?
How can probability be used to predict genetic traits?
The combination of alleles in an organism’s cells is its genotype. Remember that a gamete contains only one chromosome of each pair. But therefore it contains one o f the two alleles making up the organism's genotype.
Punnett squares show the probability that each offspring will have a given genotype. A pedigree chart can be used to trace inheritance of a trait through multiple generations of related individuals. Not all genes have one dominant and one recessive allele.
Alleles show codominance meaning that heterozygotes express both the dominant and recessive phenotypes rather than a blend of the two. Some genes have more than two possible alleles. In humans and many other animals have a single pair of chromosomes called sex chromosomes that determines an individual sec. Human sex chromosomes are the X chromosomes and the Y chromosome. An XX individual is female while XY individual is male. The X chromosome is much larger than Y.
Hemophilia, a blood clotting disorder and is determined by a single gene on the X chromosome. A father with hemophilia will pass the recessive allele to all of his daughters. Assuming that the mother is homozygous dominant the daughters will be carriers of disorders.
Essential Questions
What is genetics?
Why is understanding genetics important for scientist?
How can probability be used to predict genetic traits?
Objectives
- Describe and/or predict observed patterns of inheritance (i.e., dominant, recessive, co-dominance, incomplete dominance, sex-linked, polygenic, and multiple alleles).
- Describe processes that can alter composition or number of chromosomes
- Describe how the processes of transcription and translation are similar in all organisms.
Vocabulary!
A gene- a dna sequence that specifies a protein
An allele- is a version of a gene. Each sexually reproducing organism inherits two alleles of each gene.
A polygenic trait-is determined by many genes
A genotype- is the combination of alleles of a particular gene
A phenotype- is the appearance of a trait
A dominant- allele is expressed if the individual inherits just a single copy of the allele
A recessive- allele is expressed only if the individual inherits two copies of the allele
Incomplete dominance- the heterozygous phenotype is “in between” the homozygous phenotypes.
Co-dominant alleles- show that heterozygotes express both the dominant and recessive phenotypes, rather than a blend of the two.
Multiple alleles- in the population even though each individual still carries only two alleles
Sex- linked trait- is determined by genes on either the X or Y chromosome.
An allele- is a version of a gene. Each sexually reproducing organism inherits two alleles of each gene.
A polygenic trait-is determined by many genes
A genotype- is the combination of alleles of a particular gene
A phenotype- is the appearance of a trait
A dominant- allele is expressed if the individual inherits just a single copy of the allele
A recessive- allele is expressed only if the individual inherits two copies of the allele
Incomplete dominance- the heterozygous phenotype is “in between” the homozygous phenotypes.
Co-dominant alleles- show that heterozygotes express both the dominant and recessive phenotypes, rather than a blend of the two.
Multiple alleles- in the population even though each individual still carries only two alleles
Sex- linked trait- is determined by genes on either the X or Y chromosome.