In Pasteur's swan-neck flask experiment, the importance of the S-shaped curves in the flasks was twofold. The curves allowed entry of air but excluded __________.
a. airborne microorganisms
b. nutrients
c. heat
d. viruses
e. oxygen
Ans: a. airborne microorganisms
You might also like to view...
Of the subphases of prophase I of meiosis, the phase at which mammalian egg cells are arrested for years during oogenesis is
A) leptotene. B) zygotene. C) pachytene. D) diplotene. E) diakinesis.
Commercial canning processes
A. are geared to destroy Clostridium botulinum spores. B. kill all endospores. C. are especially needed on low acid foods. D. are 12D processes (designed to kill 1012 endospores). E. are geared to destroy Clostridium botulinum spores, are especially needed on low acid foods, AND are 12D (designed to kill 1012 endospores) processes.
In Drosophila, an individual female fly was observed to be of the XXY chromosome complement (normal autosomal complement) and to have white eyes as contrasted with the normal red eye color of wild type. The female's mother and father had red eyes
The mother, however, was heterozygous for the gene for white eyes. Knowing that white eyes are X-linked and recessive, present an explanation for the genetic and chromosomal constitution of the XXY, white-eyed individual. It is important that you state in which parent and at what stage the chromosomal event occurred that caused the genetic and cytogenetic abnormality.
What is the correct order of steps of morphogenesis in Drosophila melanogaster?a. Gap genes divide the body into broad regionsb. Establishment of anterior / posterior axesc. Homeotic genes determine which body parts arise from each regiond. Pair-rule genes are activated in order to develop a preliminary segmentation pattern
A. a - b - c - d B. a - d - c - b C. a - d - b - c D. b - a - d - c E. b - a - c - d