#6 Take Home Exam Flashcards
Chromatin
When a chromosome is in its diffuse form, the DNA/histone complex is called a chromatin
Chromosome
A threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes
Binary fusion
Asexual reproduction of singled celled organisms results in two genetically identical offspring
Kinetochore
A complex of proteins associated with the centromere of a chromosome during cell division, to which the microtubules of the spindle attach
Centrioles
The centrioleshelp intheformation ofthespindle fibers that separatethechromosomes during cell division (mitosis)
Spindle fibers
in regards to cell division
They form a protein structure that divides the genetic material in acell. Thespindleis necessary to equallydividethe chromosomes in a parentalcellinto two daughtercellsduring both types of nucleardivision:mitosisand meiosis
Diploid cell
Any cell with paired sets of homologous chromosomes
Homologous pair
in regards chromosomes
Two chromosomes composing a pair, because they share the same gene locations along their length
Haploid cell
Any cell with only one of each chromosome type
Gamete
A mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote
(DNA) What is euchromatin?
Euchromatin is a lightly packed form of chromatin that is enriched in genes, and is often under active transcription
(DNA) What is heterochromatin?
chromosome material of different density from normal (usually greater), in which the activity of the genes is modified or suppressed
(DNA) What are histone proteins and what is a nucleosome?
highly alkaline proteins found in eukaryotic cell nuclei that package and order the DNA into structural units called nucleosomes
(DNA) What is a gene?
A unit of DNA that is usually located on a chromosome and that controls the development of one or more traits and is the basic unit by which genetic information is passed from parent to offspring
(DNA) What is an allele?
different versions of the same gene
(DNA) What are sister chromatids?
identical copies formed by the DNA replication of a chromosome, with both copies joined together by a common centromere. In other words, a sister chromatid may also be said to be ‘one-half’ of the duplicated chromosome
(DNA) What is a centromere?
The region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, during cell division.Different versions of the same gene
(interphase) describe what happens during G1
In G1 (first gap) : the cell grows and carries out normal functions
(interphase) describe what happens during S
In S : Chromosomes are duplicated (synthesized)
(interphase) describe what happens during G2
In G2 (second gap) : cell grows in final preparation for cell division
What are the four phases of mitosis and cytokinesis?
Prophase
Metaphase
Anaphase
Telophase
What is the end product of mitosis?
The end result of mitosis is two identical daughter cells
What does it mean that DNA replication is semiconservative.
Semi-conservative replication meansthat duringDNA replication, the two strands of nucleotides separate. Hence each daughter strand has half of theDNAfrom the original strand and half newly-formedDNA
What is the end product of mitosis in regards to number of daughter cells and their
genetics?
The result of mitosis is two identical daughter cells, genetically identical to the original cell, all having 2N chromosomes
What is the end product of meiosis in regards to number of daughter cells and their
genetics?
Meiosis produces four, genetically unique, haploid gametes in diploid organisms
Cytokinesis
Cytokinesis, the division of the cytoplasm to form two new cells, overlaps with the final stages of mitosis.
In animal cells, the pinch crease is known as the cleavage furrow.
