Question

this section describes how dna is packaged in form chromosomes. it also tells how the cell duplicates its dna before cell division. dna and chromosomes 1. circle the letter of the location of dna in prokaryotic cells. a. nucleus b. mitochondria c. cytoplasm d. vacuole 2. is the following sentence true or false? most prokaryotes contain a single, circular dna molecule. 3. eukaryotic dna is generally located in the cell ______ in the form of a number of chromosomes. 4. is the following sentence true or false? all organisms have the same number of chromosomes. 5. is the following sentence true or false? the e. coli chromosome is longer than the diameter of an individual e. coli bacterium. 6. circle the letter of each sentence that is true about chromosome structure. a. the dna in eukaryotic cells is very loosely packed. b. prokaryotic cells contain more dna than eukaryotic cells. c. a human cell contains more than 1 meter of dna. d. the dna of the smallest human chromosome is nearly 10 times as long as most bacterial chromosomes. 7. eukaryotic chromosomes contain both dna and protein, packed together to form. 8. what are histones? 9. why are individual chromosomes visible only during mitosis? 10. is the following sentence true or false? changes in chromatin structure and histone - dna binding are associated with changes in gene activity. 11. what do nucleosomes do?

Explanation:

1. Prokaryotic cells lack a nucleus and their DNA is in the cytoplasm.
2. Most prokaryotes have a single, circular DNA molecule.
3. Eukaryotic DNA is in the nucleus as chromosomes.
4. Different organisms have different chromosome numbers.
5. The E. coli chromosome is much longer than the cell diameter.
6. Eukaryotic DNA is tightly - packed, eukaryotes have more DNA than prokaryotes, a human cell has over 1 meter of DNA, and human chromosomes are much longer than bacterial ones.
7. Eukaryotic chromosomes are a combination of DNA and protein.
8. Histones are proteins that DNA wraps around in eukaryotic cells for packaging.
9. During mitosis, chromatin condenses into visible chromosomes.
10. Changes in chromatin and histone - DNA binding affect gene activity.
11. Nucleosomes are the basic units of DNA packaging in eukaryotes, formed by DNA wrapped around histone proteins.

Answer:

1. c. cytoplasm
2. True
3. nucleus
4. False
5. True
6. c. A human cell contains more than 1 meter of DNA; d. The DNA of the smallest human chromosome is nearly 10 times as long as most bacterial chromosomes
7. True
8. Histones are proteins around which DNA wraps in eukaryotic cells for packaging.
9. During mitosis, chromatin condenses into tightly - coiled structures called chromosomes, making them visible under a microscope.
10. True
11. Nucleosomes are the basic structural units of DNA packaging in eukaryotes. They consist of DNA wrapped around a core of histone proteins, helping to compact DNA and regulate gene expression.