Which of the following statements about membrane-enclosed organelles is true?
(a) In a typical cell, the area of the endoplasmic reticulum membrane far exceeds the area of plasma membrane.
(b) The nucleus is the only organelle that is surrounded by a double membrane.
(c) Other than the nucleus, most organelles are small and thus, in a typical cell, only about 10% of a cell's volume is occupied by membrane-enclosed organelles; the other 90% of the cell volume is the cytosol.
(d) The nucleus is the only organelle that contains DNA.
Choice (a) is true; the area of the endoplasmic reticulum membrane is 20–30 times that of the plasma membrane in a typical cell. Chloroplasts and mitochondria are also surrounded by a double membrane [choice (b)]. The cytosol is about half the volume of a typical eukaryotic cell, with membrane-enclosed organelles making up the other half of the volume [choice (c)]. Chloroplasts and mitochondria also carry their own genome, whereas the nucleus carries the genome of the organism [choice (d)].
You might also like to view...
Which of the following statements about single nucleotide polymorphisms (SNPs) is correct? (Choose all that apply)
A. For some disorders, multiple SNPs plus environmental factors are necessary in order for the disorder to present itself. B. Genotyping SNPs instead of sequencing entire genomes allows researchers to find correlations between genetic risk factors and disease. C. SNPs are useful in the diagnosis of a disease but not in the prediction of an individual's risk for acquiring that disease. D. Individuals who are heterozygous for the S allele in the ?-globin gene are more likely to develop sickle-cell anemia than individuals who are homozygous for the S allele in the ?- globin gene. E. The presence of an SNP in an organism's genome when compared to the "standard" genome of that organism means that a disease condition will develop.
Minerals differ from nutrients because minerals __________
a. do not contain carbon b. are organic c. are only required in small quantities d. are essential to the diet
Which of the following conclusions was a results of Mendel's observations?
A.) Organisms that give rise to purebreds are genetically superior. B.) Organisms that have intermediate feature are self-pollinating. C.) Organisms inherit two copies of each gene, one from each parent. D.) Organisms that self-pollinate do not have "either-or" features.
An example of a modern-day jawless fish (agnathan) is a
A. angelfish. B. shark. C. perch. D. lamprey.