Genetics, Cancer & Chromosome Abnormalities

What is a tetrad?

Two homologous chromosomes containing four chromatids.

What is fertilization?

Fusion of two haploid gametes to form a diploid zygote.

What equation calculates chromosome combinations?

2^n, where n is the haploid chromosome number.

How many chromosome combinations can humans produce?

2^23 = 8,388,608.

What is nondisjunction?

Failure of chromosomes or chromatids to separate properly.

What is aneuploidy vs. polyploidy?

Aneuploidy: extra or missing individual chromosomes. Polyploidy: extra complete chromosome sets.

What is monosomy?

Missing one chromosome (2n-1).

What is trisomy?

Having one extra chromosome (2n+1).

Give an example of monosomy and trisomy.

Monosomy: Turner syndrome (45,X). Trisomy: Down syndrome (trisomy 21).

What are deletion and duplication?

Deletion: chromosome segment lost. Duplication: chromosome segment copied.

What are inversion and translocation?

Inversion: segment reverses. Translocation: segment moves to another chromosome.

What is a tumor?

An abnormal mass of cells.

What is the difference between benign and malignant tumors?

Benign: noncancerous. Malignant: cancerous and can spread.

What is the difference between tumor suppressors and proto-oncogenes?

Tumor suppressors slow growth; proto-oncogenes promote normal growth.

Name four cancer treatments.

Chemotherapy, radiation, surgery, immunotherapy.