GENETICS AND HEREDITY TEST STUDY GUIDE Flashcards
(25 cards)
What is a trait?
A characteristic determined by one’s genes like eye/hair color.
What is genetics?
The study of heredity, passing of traits from parent to offspring.
What is an allele?
Each gene in a pair of chromosomes is called an allele.
What is heredity?
The passing of traits from parent to offspring.
What does purebred mean?
Homozygous.
What is a dominant trait?
A trait that shows up.
What is a recessive trait?
The trait that does not show when paired with a dominant trait.
What is a Punnett square?
A tool used to predict the outcome of a genetic cross.
What is a phenotype?
The physical trait that shows.
What is a genotype?
The pairs of letters that represent the genetic makeup.
What is homozygous?
Two alleles that are exactly the same for a trait (e.g., RR, rr).
What is heterozygous?
Two different alleles for a trait (e.g., Rr).
What is selective breeding?
Humans choose a trait and breed two organisms for the trait.
How do we distinguish a dominant trait from a recessive trait?
The dominant trait is represented with a capital letter (e.g., RR, TT) and the recessive trait with a lower case letter (e.g., rr, tt).
What is the difference between an allele and a gene?
An allele is one version of a trait that makes a gene.
Explain the difference between homozygous and heterozygous with examples.
Homozygous is a purebred trait (e.g., RR or rr). Heterozygous is a hybrid trait (e.g., Rr or Ss).
Describe the difference between genotype and phenotype with examples.
Genotype is the allele combination (e.g., TT, Tt, tt). Phenotype is the observable trait (e.g., tall, brown, round).
What do the offspring look like if you cross a dominant homozygous parent and a recessive homozygous parent?
The genotype is Tt and the phenotype is Tall. 100%
What are the genotypes and phenotypes of the offspring when two heterozygous pea plants are crossed?
Genotypes are RR, Rr, and rr. Phenotypes are 75% round and 25% wrinkled.
Name the four blood types.
A, B, AB, and O.
Cross a person with the blood type BO and a person with AA. What percentage of the offspring would be type A blood?
50% of offspring is A.
Which chromosomes are affected by sex-linked disorders?
The X chromosome is affected by sex-linked disorders.
Name the recessive genetic disorders and sex-linked disorders discussed in class.
Genetic – sickle cell anemia and cystic fibrosis. Sex-linked – color blindness and hemophilia.
Define mitosis and meiosis. State the stages for each and compare and contrast the two processes.
Mitosis is the division of cells to make body cells with a complete set of chromosomes. Meiosis is the division of cells to create sex cells with ½ a set of chromosomes.
Mitosis stages: Prophase, Metaphase, Anaphase, Telophase. Meiosis stages: Prophase 1, Metaphase 1, Anaphase 1, Telophase 1, Prophase 2, Metaphase 2, Anaphase 2, Telophase 2.
