Genetics Study Guide

Passing of traits from parent to offpsring What is Heredity?

Different forms of a characteristic What is a trait?

Forms of a gene What is an allele?

Traits are controlled by define example Single Genes 2 alleles Freckles Multiple Alleles 2 or more alleles control a single trait Blood type Many Genes 2 or more genes control a trait Skin color Sex-Linked Alleles for a trait are on the sex chromosomes Color blindness Incomplete Dominance Blend together Pink flower Co-dominance Alleles work together; both appear AB blood type

Compare genotype and phenotype Genotype: 2 or more alleles control a trait Ex. TT, Tt,tt Phenotype: physical appearance of a trait Ex. Blond hair, green eyes Compare genotype and phenotype

Homozygous/purebred: 2 same alleles Heterozygous/hybrid: 2 different alleles Compare homozygous and heterozygous genotypes. Include purebred and hybrid

What is a Punnett Square? A tool used to predict the outcome of a genetic cross What is a Punnett Square?

Complete the following genetic crosses

List the genotypes and phenotypes for the crosses above: Tt: tall 100% TT: tall 50% Tt: tall 50% TT: 25% Tt: 50% tt: 25% List the genotypes and phenotypes for the crosses above:

A diagram that shows the inheritance of a trait through a family What is a pedigree?

Given the genotypes, describe the phenotypes: AA=normal Aa=normal aa= albino Given the genotypes, describe the phenotypes:

1. aa 2. Aa 3. Aa 4. Aa 5. aa Fill out the pedigree

3 children All female How many children does the family have? What are the sexes of the children?

How many males are albino? Females?

What is a genetic disorder? A disease caused by an abnormality in DNA What is a genetic disorder?

What causes a genetic disorder? A mutation or change in DNA What causes a genetic disorder?

What makes a mutation harmful? If it decreases the chances of an organism surviving and/or reproducing. What makes a mutation harmful?

What is a karyotype? What is it used for? A picture of a person’s chromosomes. It is used to diagnose some genetic disorders. What is a karyotype? What is it used for?

How many chromosomes do human have in each cell? 46 in body cells, 23 in sex cells How many chromosomes do human have in each cell?

The division of sex cells What is meiosis

What are the results of meiosis? 4 cells with half the number of chromosomes What are the results of meiosis?

What are the sex chromosomes for males? Females? Males: XY Females: XX What are the sex chromosomes for males? Females?

A twisted double helix (ladder) that contains the genetic information for an organism What is DNA?

Where is DNA found in a eukaryotic cell? In the nucleus Where is DNA found in a eukaryotic cell?

A twisted ladder What does DNA look like?

TTGACAT What would the complimentary nucleic acids be for AACTGTA in a strand of DNA?

How do selective breeding and genetic engineering differ?