Biology Unit 6 Part 1 Genetics Review

Based off of Review Sheet

Genotype

Alleles inherit for a gene, expressed in either a lowercase or uppercase letter

Phenotype

Trait that results from the combination of the genotype; the trait that’s expressed

Allele

Variation of a gene

Punnett Square

A diagram to predict the combination of alleles in an offspring based on the genotype of parents

Pedigree Chart

a family tree chart showing the inheritance pattern across generations

Sex Chromosomes

Pair of chromosomes that determine gender, there are two sex chromosomes, X and Y

Autosomes

All chromosomes except the sex chromosomes

Example: There are 22 pairs of autosomes in human, and 1 pair of sex chromosomes

50%

What do you inherit from your biological father and mother in terms of genetic material?

No, just means you have one copy

If you’re a carrier does that mean you have the disorder?

Law of segregation

Two chromosomes of each homologous pair separate, moving into different gametes from during meiosis

Law of independent assortment

Alleles separates independently during meiosis, separating randomly

Homozygous

Same type of alleles of a gene, aka purebred/pure

Heterozygous

Two different types of alleles of a gene, aka hybrid

Test Cross

Carried out when you want to know the genotype of an individual with a dominant phenotype. To carry it out you mate the individual with the recessive phenotype many times, and if there is an offspring that carries the recessive phenotype, the individual with be heterozygous, otherwise, it’s homozygous dominant

Complete Dominance

When the dominant allele is present it displays dominant trait

Incomplete Dominance

Neither alleles are completely dominate over the other, creates a trait that’s a mixture of both

Codominance

Both traits are equally dominant, causing both traits to be displayed at once

Gene and Allele Relationship

Alleles are different versions of the same genes