Based on the classic experiments of Creighton and McClintock with maize, crossing over involves a physical exchange between chromatids. What particular chromosomal characteristic allowed their experiments to succeed?
A) colored bands along the lengths of a chromosome
B) a chromosome with a unique cytological marker
C) a missing chromosome
D) an extra chromosome
E) three chromosomes with identical structure
Answer: B
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Genomic studies of Neanderthals, modern humans, and chimpanzees have confirmed that ____
a. humans evolved from Denisovans b. humans and Neanderthals interbred c. humans and Neanderthals are 98.8% genetically identical d. humans are direct descendants of Neanderthals e. there is a 5% difference in the coding regions of the human genome vs. the chimpanzee genome
Under which of the following taxonomic levels does E. coli fall?
a. species b. order c. class d. kingdom
Matching. Choose the one most appropriate answer
for each. 1. ___ nephron 2. ___ aldosterone 3. ___ tubular secretion 4. ___ ADH 5. ___ conduction 6. ___ convection 7. ___ pilomotor response 8. ___ ectothermic 9. ___ evaporation 10. ___ glomerular filtration 11. ___ hemodialysis 12. ___ hypothermia 13. ___ heterothermic 14. ___ radiation 15. ___ tubular reabsorption A. do not maintain the same body temperature at all times; are capable of internal heat production B. heat energy is released to the air when liquid water converts to gaseous form C. bulk flow of protein-free plasma from capillaries into Bowman’s capsule D. animals with more or less constant body temperature E. emission of heat from body surface when environmental temperature is lower than the body temperature F. movement of ions from peritubular capillaries into nephron tubules G. loss of too much body heat H. heat next to the body’s surface undergoes mass transport by air or water currents I. active and passive transport of solutes from peritubular capillaries into the glomerular capillaries J. a long, slender, tubular unit in the vertebrate kidney that forms urine K. body temperatures rise and fall with environmental changes L. secreted by adrenal glands; influences sodium reabsorption M. passive transport of water; active and passive transport of solutes out of the nephron into peritubular capillaries N. heat energy is transferred from high to low temperature regions due to collisions between adjacent molecules O. released from the posterior lobe of the pituitary in response to hypothalamic signals P. toxic substances are extracted from blood circulating in cellophane tubes suspended in a warm-water bath Q. erection of hairs and feathers by smooth muscles in the skin
A rare genetic disorder called Gaucher disease may strike as many as one in 450 people of ____ descent
a. Middle Eastern
b. Western European c. African American d. British e. Eastern European