Principles of Genetics Chapter 3- Calista Velasquez

Who formed the foundational work on genetics?

Gregor Mendel

What did Mendel’s experiment show?

Showed traits are inherited through genes.

What did Mendel’s P1 generation show?

True breeding parents with contrasting traits

What happened when Mendel crossed yellow and green peas?

All yellow (yellow dominant)

What is Mendel’s Law of Segregation?

Alleles separate during gamete formation

What is a punnett square?

Chart predicting genetic outcomes.

How are punnett squares used in biotechnology?

Predict traits, disease risks, breeding results.

What is the Law of Independent Assortment?

Genes for traits sort independently

Why is the Law of Independent Assortment important in biotechnology?

Explains genetic variation for research/reproduction.

What is a testcross?

Cross unknown genotype with recessive one.

What is homozygous?

Two identical alleles

What is heterozygous?

Two different allelles

Why are testcrosses important in biotechnology?

Identifies genotypes for genetic analysis.

What is incomplete dominance?

Neither allele fully dominates; blend appears

What does incomplete dominance show in biotechnology?

Helps study gene expression and blending traits.

What is codominance?

Both alleles fully expressed equally

What is an example of a trait determined by codominance?

Human blood type AB

Why is codominance important in biotechnology?

Used in genetic mapping and genetic research

What is polygenic inheritance?

Trait controlled by many genes

What is a classic example of polygenic inheritance?

Skin color, height.

What type of results does polygenic inheritance produce?

Wide range of variations.

How is sex determined?

By XY chromosomes (XX= female, YY= male)

Why is sex determination important in biotechnology?

Affects reproduction, genetics, and medical research.

How are sex linked traits determined?

Determined by genes on sex chromosomes (X or Y)

Why are males more likely to express X-linked disorders?

Only one X, so one recessive allele causes disorders.

How do females express sex-linked disorders?

Need two recessive alleles to express it

Why is it important to understand sex-linked inheritance in biotechnology?

Helps in gene therapy, genetic testing, and disease research

What are chromosomal alterations?

Changes in chromosome structure or number.

What is deletion?

Missing chromosome segment

What is inversion?

Segment flips direction

What is translocation?

Segment moves to another chromosome

What is duplication?

Segment repeats 

What is crossing over?

Exchange of DNA between homologous chromosomes

Why is crossing over important in science and biotechnology?

Increases genetic diversity, aids genetic mapping

When does crossing over occur?

During prophase 1 of meiosis

What is nondisjunction?

Chromosomes fail to separate in meiosis

What is the result of nondisjunction?

Abnormal chromosome numbers

What diseases does nondisjunction help explain?

Down, Turner, Klinefelter syndrome

What is Down’s syndrome?

Extra chromosome 21

What is Turner syndrome?

Missing one X (XO).

What is Klinfelter syndrome?

Extra X in males (XXY)