Explain how to determine if a nondisjunction occurred during meiosis I or meiosis II and what the genetic
consequences are for the resulting fertilized gametes.What will be an ideal response?
ANSWER: If nondisjunction occurs in meiosis I, all gametes will be abnormal and carry either both
members of a chromosomal pair or neither member of the pair. Nondisjunction in meiosis II
produces 50% normal haploid cells and 50% abnormal cells, one with an extra copy of a
chromosome and one missing a chromosome. Fertilization between gametes with an extra
copy of a chromosome and a haploid gamete will result in trisomy; fusion of a haploid
gamete and one missing a copy of a specific chromosome will result in monosomy. The
phenotypic effects of aneuploidy range from minor physical symptoms to devastating and
lethal conditions. Among survivors, phenotypic effects often include behavioral deficits and
intellectual disability.
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A template strand of DNA is read in the ____________ direction in order to direct synthesis of RNA in the ____________ direction
A. 3'-5'; 3'-5' B. 5'-3'; 3'-5' C. 3'-5'; 5'-3' D. 5'-3'; 5'-3'
_____ is defined as a decrease in the response to an ongoing stimulus
a. Perception c. Sensory adaptation b. Visual accommodation d. Somatic sensation
An hypothesis currently getting a lot of attention
concerning the origin of biological molecules is that they originated a. in hot springs. b. near volcanoes. c. near hydrothermal oceanic vents. d. in salt lakes. e. in tidal pools.
Membranous areas in the infant skull that join bones and function to allow for rapid growth of the brain are known as ________
A) fibrous membrane B) osteocytes C) fontanels D) lacunae