BCHM 4360 Exam 1 WITH VERRIFIED
ANSWERS 2025 |2026
Genetic information is packaged into at least one very long DNA molecule -- a __________. - answ-
chromosome
Each chromosome contains ___ double-stranded DNA molecule - answ-one
Each chromosome has many _____ and other regions of DNA within a single molecule. Regions between
genes are __________. - answ-genes, intergenic
Eukaryotes have ______ chromosomes, most bacteria and archaea have ________ chromosomes. -
answ-linear, circular
____ complex organisms tend to have more _______ arranged genes. Example is _____. - answ-less,
densely, yeast
Humans have __ chromosomes while the kingfisher has ___ and fission yeast have _. - answ-46, 132, 6
Ploidy refers to - answ-how many sets of identical chromosomes an organism has
What is ploidy of humans and human sex cells? - answ-diploid, haploid
Each individual chromosome is __________ between the mother and the father. - answ-homologous
_________ cells have multiple sets of chromosomes and are common in some plants. However, some
human cells such as _____ cells are also _________. - answ-Polyploid, liver, polyploid
,Eukaryotic cells can have __________ DNA to the chromosomal DNA found in the _______. - answ-
additional, nucleus
____________ have their own, usually ________, chromosomes. - answ-Mitochondria, circular
____________ also have their own chromosomes. - answ-Chloroplasts
____________ and ____________ are thought to have derived from ancestral free-living bacteria that
were absorbed and maintained by other single-celled organisms. - answ-Mitochondria, chloroplasts
Bacterial cells often have additional DNA within their cells -- small circular molecules known as
________. - answ-plasmids
Viruses are infectious agents and carry genetic information as small ___ or ___ chromosomes. These
chromosomes can be ______ or _______, and ______ or ______ stranded. - answ-DNA, RNA, linear,
circular, double, single
Chromosomes must be ______ and ___________ to the next generation of cells faithfully. - answ-
copied, transferred
Cells must copy DNA and separate the chromosomes ______ they can divide. - answ-before
In somatic cells, the sequence of events of cell division is called what? - answ-the cell cycle
The chromosome cycle is ___________ with the cell cycle. - answ-coordinated
What are the four main phases to the cell cycle? - answ-G1, S, G2, M
Describe what happens in G1. - answ-Cells grow to a minimum size required for the next stage
,Describe what happens in S. - answ-DNA is copied, duplicating the chromosomes. The two sister
chromatids remain associated with one another.
Describe what happens in G2. - answ-The cell prepares for mitosis
Describe what happens in M. - answ-Sister chromatids are separated and a full set of chromosomes is
moved to each pole of the cell.
On entry to which cell cycle phase does the nuclear envelope break down? - answ-M
In condensed chromosomes, DNA appears as large _____ anchored near the middle of the chromosome.
- answ-loops
Chromosomes consist of ___ plus __________ proteins that help condense the DNA into a smaller space
and _______ the genome. - answ-DNA, packaging, protect
The DNA-protein complex that makes up chromosomes is called _________. - answ-chromatin
What occurs in the first packing stage of the chromatin? - answ-Small positively-charged proteins bind to
counteract the negative charges on DNA backbone
In bacteria, the first packing stage of chromatin _____ the DNA forming the _________, and the bending
induces ____________. - answ-bends, nucleoid, supercoiling
In eukaryotes, the basic binding proteins are called ________. - answ-histones
How many core histones are there and what are they called? - answ-4, H2A, H2B, H3, H4
Which two amino acids are histones rich in and why? - answ-lysine and arginine due to positive charges
, DNA wraps around a histone complex in a ____-handed manner to form a __________. - answ-left,
nucleosome
Which two histone dimers associate with DNA first? - answ-H3, H4
Which two histone dimers associate last to form the octamer? - answ-H2A, H2B
About how many base pairs of DNA wrap around the histone octamer to form the nucleosome? - answ-
146
Removing the histone octamer leaves what kind of supercoiled DNA? - answ-negative
Each core histone has a(n) _-terminal tail that extends outward between the DNA and coils. - answ-N
The histone tails are up to __ amino acids long and have an _________ structure. - answ-25, undefined
Why do the histone tails interact with other nucleosomes? - answ-to help compact DNA further
What are the five mutant variations of histone H2A? - answ-H2A.X, H2A.Z, MacroH2A1, MacroH2A2,
H2A-Bbd
What is the proposed function for H2A.X? - answ-DNA damage signaling
What is the proposed function for H2A.Z? - answ-transcriptional silencing
What is the proposed function for MacroH2A1 and MacroH2A2? - answ-binds inactive X chromosome
What is the variant histone for H2B? - answ-H2B.1
What are the four variant histones for H3? - answ-CENP-A, H3FA3, H3.3B, H3FT
ANSWERS 2025 |2026
Genetic information is packaged into at least one very long DNA molecule -- a __________. - answ-
chromosome
Each chromosome contains ___ double-stranded DNA molecule - answ-one
Each chromosome has many _____ and other regions of DNA within a single molecule. Regions between
genes are __________. - answ-genes, intergenic
Eukaryotes have ______ chromosomes, most bacteria and archaea have ________ chromosomes. -
answ-linear, circular
____ complex organisms tend to have more _______ arranged genes. Example is _____. - answ-less,
densely, yeast
Humans have __ chromosomes while the kingfisher has ___ and fission yeast have _. - answ-46, 132, 6
Ploidy refers to - answ-how many sets of identical chromosomes an organism has
What is ploidy of humans and human sex cells? - answ-diploid, haploid
Each individual chromosome is __________ between the mother and the father. - answ-homologous
_________ cells have multiple sets of chromosomes and are common in some plants. However, some
human cells such as _____ cells are also _________. - answ-Polyploid, liver, polyploid
,Eukaryotic cells can have __________ DNA to the chromosomal DNA found in the _______. - answ-
additional, nucleus
____________ have their own, usually ________, chromosomes. - answ-Mitochondria, circular
____________ also have their own chromosomes. - answ-Chloroplasts
____________ and ____________ are thought to have derived from ancestral free-living bacteria that
were absorbed and maintained by other single-celled organisms. - answ-Mitochondria, chloroplasts
Bacterial cells often have additional DNA within their cells -- small circular molecules known as
________. - answ-plasmids
Viruses are infectious agents and carry genetic information as small ___ or ___ chromosomes. These
chromosomes can be ______ or _______, and ______ or ______ stranded. - answ-DNA, RNA, linear,
circular, double, single
Chromosomes must be ______ and ___________ to the next generation of cells faithfully. - answ-
copied, transferred
Cells must copy DNA and separate the chromosomes ______ they can divide. - answ-before
In somatic cells, the sequence of events of cell division is called what? - answ-the cell cycle
The chromosome cycle is ___________ with the cell cycle. - answ-coordinated
What are the four main phases to the cell cycle? - answ-G1, S, G2, M
Describe what happens in G1. - answ-Cells grow to a minimum size required for the next stage
,Describe what happens in S. - answ-DNA is copied, duplicating the chromosomes. The two sister
chromatids remain associated with one another.
Describe what happens in G2. - answ-The cell prepares for mitosis
Describe what happens in M. - answ-Sister chromatids are separated and a full set of chromosomes is
moved to each pole of the cell.
On entry to which cell cycle phase does the nuclear envelope break down? - answ-M
In condensed chromosomes, DNA appears as large _____ anchored near the middle of the chromosome.
- answ-loops
Chromosomes consist of ___ plus __________ proteins that help condense the DNA into a smaller space
and _______ the genome. - answ-DNA, packaging, protect
The DNA-protein complex that makes up chromosomes is called _________. - answ-chromatin
What occurs in the first packing stage of the chromatin? - answ-Small positively-charged proteins bind to
counteract the negative charges on DNA backbone
In bacteria, the first packing stage of chromatin _____ the DNA forming the _________, and the bending
induces ____________. - answ-bends, nucleoid, supercoiling
In eukaryotes, the basic binding proteins are called ________. - answ-histones
How many core histones are there and what are they called? - answ-4, H2A, H2B, H3, H4
Which two amino acids are histones rich in and why? - answ-lysine and arginine due to positive charges
, DNA wraps around a histone complex in a ____-handed manner to form a __________. - answ-left,
nucleosome
Which two histone dimers associate with DNA first? - answ-H3, H4
Which two histone dimers associate last to form the octamer? - answ-H2A, H2B
About how many base pairs of DNA wrap around the histone octamer to form the nucleosome? - answ-
146
Removing the histone octamer leaves what kind of supercoiled DNA? - answ-negative
Each core histone has a(n) _-terminal tail that extends outward between the DNA and coils. - answ-N
The histone tails are up to __ amino acids long and have an _________ structure. - answ-25, undefined
Why do the histone tails interact with other nucleosomes? - answ-to help compact DNA further
What are the five mutant variations of histone H2A? - answ-H2A.X, H2A.Z, MacroH2A1, MacroH2A2,
H2A-Bbd
What is the proposed function for H2A.X? - answ-DNA damage signaling
What is the proposed function for H2A.Z? - answ-transcriptional silencing
What is the proposed function for MacroH2A1 and MacroH2A2? - answ-binds inactive X chromosome
What is the variant histone for H2B? - answ-H2B.1
What are the four variant histones for H3? - answ-CENP-A, H3FA3, H3.3B, H3FT
