Notes in Chapter 4: Chromsome Structure and Function

To Subscribe, use this Key

Status	Last Update	Fields
Published	01/18/2025	{{c1::Chromosomes}} must be copied and transferred to the next generation of cells {{c2::faithfully}}
Published	01/18/2025	Genetic information is packaged into at least one very long DNA molecule – a {{c1::chromosome}}, which contains one {{c2::double-stranded}} DNA m…
Published	01/18/2025	Cells must copy {{c1::DNA}} and separate {{c1::the chromosomes}} before they can divide.
Published	01/18/2025	Each chromosome has many genes and other regions of DNA (introns, regulatory regions, etc.) within a single molecule. The regions between genes a…
Published	01/18/2025	In somatic cells, the sequence of events of cell division is called {{c1::the cell cycle}}. The {{c2::chromosome cycle}} is coordinated with this.
Published	01/18/2025	Eukaryotes have {{c1::linear}} chromosomes; most bacteria and archaea have {{c2::circular}} chromosomes
Published	01/18/2025	In the {{c1::G1 (gap phase 1):: cell cycle phase}} – cells grow to a minimum size required for the next stage
Published	01/18/2025	In the {{c1::S (synthesis phase):: cell cycle phase}} – DNA is copied, duplicating the chromosomes.  The two copies (sister chromatids) remain as…
Published	01/18/2025	Gene distribution varies widely among organisms – less complex organisms like yeast tend to have {{c1::more densely}} arranged genes. Gene density {{c…
Published	01/18/2025	In the {{c1::G2 (gap phase 2):: cell cycle phase}} – the cell prepares for mitosis.
Published	01/18/2025	In the {{c1::M (mitotic phase): cell cycle phase}} – sister chromatids are separated and a full set of chromosomes is moved to each pole of the cell (…
Published	01/18/2025	What is the set number of chromosomes of the following species?- Humans: {{c1::46 (23 from each parent)}}- Kingfisher: {{c1::132}}- Dogs:&nb…
Published	01/18/2025	{{c1::Ploidy}} refers to how many sets of identical chromosomes an organism has.
Published	01/18/2025	Humans are {{c1::diploid}} – two copies of chromosomes 1-22 and either two X chromosomes or one X and one Y.Human egg and sperm cells are {{c1::haploi…
Published	01/18/2025	On entry to M phase:The nuclear membrane {{c1::breaks down}}. Chromosomes {{c1::condense}}, but sister chromatids are still associatedCentromeres…
Published	01/18/2025	Condensed chromosomes have characteristic lengths and banding patterns. A {{c1::karyotype}} is a display of the chromosomes from an individu…
Published	01/18/2025	In {{c1::condensed chromosomes}}, DNA appears as {{c2::large loops}} anchored near the middle of the chromosome.
Published	01/18/2025	When the chromosomes from two parents are combined in a singlenucleus, there are {{c1::two copies (1 from each parent):: # copy/copies}} of each chrom…
Published	01/18/2025	Chromosome 1 from the mother is homologous to chromosome 1 fromthe father - this means the chromosomes have the same {{c1::genes}} and {{c1::gene orde…
Published	01/18/2025	▪ Chromosomes consist of DNA plus {{c1::packaging proteins}} that help condense the DNA into a smaller space and protect the genome▪ Th…
Published	01/18/2025	{{c1::Polyploid}} cells have multiple sets of chromosomes and are found at certain life-stages in some organisms. {{c1::Polyploidy}} is particula…
Published	01/18/2025	The first packing stage of DNA into chromosomes is the binding of {{c1::small positively charged proteins}} along DNA, counteracting the negative…
Published	01/18/2025	Eukaryotic cells {{c1::can:: can/cannot}} have additional DNA to the chromosomal DNA found in the nucleus.
Published	01/18/2025	▪ In eukaryotes, the basic binding proteins for DNA are called {{c1::histones}}
Published	01/18/2025	Histones are rich in {{c1::lysine:: AA}} and {{c1::arginine: AA}} which have positive charges and stabilize the DNA- histone interaction
Published	01/18/2025	▪ DNA wraps around a histone complex in a left handed manner to form a {{c1::nucleosome}}. The histone complex at the center is the {{c2::histone octa…
Published	01/18/2025	▪ The {{c1::H3-H4 heterotetramer:: part of the histone octamer}} associates with DNA▪ The two {{c1::H2A-H2B dimers}} then associate to form the octame…
Published	01/18/2025	▪ About {{c1::146:: #}} bp of DNA wraps around the octamer to form the {{c1::nucleosome}}.
Published	01/18/2025	▪ The DNA is wound around the histone octamer in a {{c2::left:: left or right}} handed direction – when the octamer is removed, this leaves {{c1::nega…
Published	01/18/2025	{{c1::Viruses}} are infectious agents and carry genetic information as small DNA or RNA chromosomes.  {{c1::Viral}} chromosomes can be {{c2::line…
Published	01/18/2025	Bacterial cells often have additional DNA within their cells – small circular DNA molecules known as {{c1::plasmids}}.  They typically encode a f…
Status	Last Update	Fields