chapter 11 genetics

most of the centromere and telomere structures consist of ___.

heterochromatin

when a circular DNA gets under rotated by the action of cellular enzymes, the DNA is said to exhibit ___.

negative supercoiling

eukaryotic DNA consists of ___

unique sequences of DNA, highly repetitive DNA sequences, moderately repetitive DNA sequences

T or F? The C value, which indicates the amount of DNA in a haploid genome, always correlates to the complexity of the organism

False

the eukaryotic protein critical for organizing chromatin structure is histone. which of the following histone proteins is not included in the histone core that is often described as the beads?

H1

a distinct clump of prokaryotic DNA observed via electron microscopy is referred to as a ___.

nucleoid

one example of non-mendelian inheritance is uniparental inheritance. Choose the definition of uniparental inheritance. Select the examples of genetic material that are uniparentally inherited in sexually reproducing eukaryotes

one parent transmits all genetic information to all offspring mitochrondial DNA, plastid DNA

select the function of the centromere in the transmission of genetic information

the attachment point of sister chromatids

T or F? mtDNA and cpDNA contain rRNA and tRNA genes of there own for their organelle specific functions

true

which of the following statements about euchromatin and heterochromatin are correct? a. euchromatin undergoes condensation and decondensation throughout the cell cycle b. the majority of transcription takes place on euchromatin c. heterochromatin is less condensed than euchromatin d. most genes are present in heterochromatin e. euchromatin largely consists of repeated sequences

a. euchromatin undergoes condensation and decondensation throughout the cell cycle b. the majority of transcription takes place on euchromatin

complete the sentence. Histone portions ...

associate with DNA and compact DNA within the nucleus

arrange the features of eukaryotic chromosome packing in order from smallest unit to the largest unit genome, nucleosome, chromosome, coiled fiber, base pairs

base pairs nucleosome coiled fiber chromosome genome

which statement about cellular DNA is incorrect? a. supercoiling of cellular DNA is controlled by topoisomerases b. supercoiling makes the separation of the two strands of DNA easier for replication and transcription c. DNA exists in the cell as very long, tightly packed molecules d. most cellular DNA is positively supercoiled e. supercoiling allows cellular DNA to be packed into a small space

d. most cellular DNA is positively supercoiled

when a solution containing double-stranded DNA is heated, the hydrogen bonds that hold the two strands can be weakened and eventually broken, separating the strands completely. this process is called ___.

denaturation

which of the following two molecules has the lower melting temperature?

the one with lower percentage of G-C base pairs that stabilize DNA duplexes

Gunter Korge examined several proteins that are secreted from the salivary glands of Drosophila melanogaster during larval development. One protein, called protein fraction four, was encoded by a gene found by deletion mapping to be located on the X chromosome at position 3C. (G. Korge. 1975. Proceedings of the National Academy of Sciences of the United States of America 72:45504554). Korge observed that, about five hours before the first synthesis of protein fraction four, an expanded and puffed-out region formed on the X chromosome at position 3C. This chromosome puff disappeared before the end of the third larval instar stage, when the synthesis of protein fraction four ceased. He observed that there was no puff at position 3C in a special strain of flies that lacked secretion of protein fraction four. 1. what is the chromosome puff at position 3C? 2. why does the disappearance of the puff at position 3C roughly coincide with lack the secretion of protein fraction 4?

1. a region of active transportation 2. the disappearance of the puff at region 3C indicates a lack of transcription from the region with gene for protein fraction 4

classify each statement as euchromatin, heterochromatin, or both. 1. is loosely packed 2. has a high level of transcription 3. is found in prokaryotes 4. is the major state of most genes 5. is a state of DNA organization 6. is tightly packed 7. has a low level of transcription 8. is the major state of inactive X chromosome

1. euchromatin 2. euchromatin 3. euchromatin 4. euchromatin 5.both 6. heterochromatin 7. heterochromatin 8. heterochromatin

complete the following sentences about DNA packaging. 1. the less condensed form of chromatin is ___ 2. the inactive form of chromatin is ___ 3. a core composed of eight ___ proteins interacts with DNA through hydrogen bonding and ionic bonds 4. if DNA structure is described as "beads-on-a-string" a bead is a ___ 5. the more darkly staining form of chromatin is ___ 6. if DNA structure is described as "beads on a string," the "string" is the ___ 7. a ___ is a DNA-protein complex

1. euchromatin 2. heterochromatin 3. histone 4. nucleosome 5. heterochromatin 6. DNA molecule 7. nucleosome

classify each of the descriptions below as a characteristic of mitochondria, chloroplasts, or both. 1. perform cellular respiration 2. contain cristae 3. perform photosynthesis 4. contain grana 5. contain DNA 6. produce energy 7. found in plants

1. mitochondria 2. mitochondria 3. chloroplast 4. chloroplast 5. both 6. both 7. both

In a circular bacterial chromosome, the structure of DNA is a _1_ double helix. If DNA is twisted in the _2_ direction, it becomes overwound. Overwinding results in _3_ supercoiling. If DNA is twisted in the _4_ direction, it becomes underwound. Underwinding results in _5_ supercoiling. One effect of _6_ supercoiling in bacterial chromosomes is to promote separation of the two strands of DNA in the double helix.

1. right-handed 2. right-handed 3. positive 4. left-handed 5. negative 6. negative

which of the following are true of endosymbiotic theory? a. explains the origin of some eukaryotic organelles, such as mitochondria b. provides insight about why chloroplasts can survive outside of a eukaryotic cell c. explains why chloroplasts contain circular DNA similar to bacteria d. states that an ancestral eukaryotic cell engulfed a photosynthetic photo bacteria e. explains the origin of all organelles found within a eukaryotic cell

a. explains the origin of some eukaryotic organelles, such as mitochondria c. explains why chloroplasts contain circular DNA similar to bacteria d. states that an ancestral eukaryotic cell engulfed a photosynthetic photo bacteria e. explains the origin of all organelles found within a eukaryotic cell

besides the nuclear DNA, certain organelles contain DNA of their own. Which of the following organelle(s) contain DNA of their own? a. mitochondria b. golgi apparatus c. endoplasmic reticulum d. chloroplasts

a. mitochondria d. chloroplasts

select the statements that accurately describe the structure or function of mitochondria a. mitochondrial DNA is packaged with histones b. the synthesis of adenosine triphosphate (ATP) occurs inside the mitochondria c. mitochondria are included in the endomembrane system d. mitochondria regular apoptosis e. mitochondria have a permeable inner membrane and an impermeable outer membrane f. the configuration of mitochondria does not change

b. the synthesis of adenosine triphosphate (ATP) occurs inside the mitochondria d. mitochondria regular apoptosis

how does chromosome compaction differ during metaphase and interphase in eukaryotes

chromosomes are more compacted in metaphase than in interphase

which of the following terms describes the tertiary structural organization of chromosomal DNA that allows the long strand to be packed and fit into the cytoplasm?

supercoiling