Geoff Has Begun Uttering One-Word Holophrases (E

question 51

Multiple Choice

Geoff has begun uttering one-word holophrases (e.g., "Dada!") . About how old is Geoff likely to be?

• A) 3 months
• B) 6 months
• C) 1 year
• D) 2 years

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Definitions:

Chromosome

A long, continuous thread of DNA that contains numerous genes and regulatory information, present in the nucleus of most living cells.

BRCA1 Gene

A gene that produces a protein playing a key role in repairing damaged DNA; mutations in BRCA1 can significantly increase the risk of breast and ovarian cancer.

Variant

An individual or group that exhibits differences in physical traits, behavior, or genetic composition from the typical or expected form.

Tumor-Suppressor Gene

A tumor-suppressor gene is a gene that suppresses cell growth and proliferation. Many tumor-suppressor genes are transcription factors activated by stress or DNA damage that arrest mitosis until DNA can be repaired. Mutations interfering with their expression can lead to excessive proliferation and cancer.