Chapter 15 Flashcards
Human body has how many cells
10-50 trillion
Mitosis ensures 2 daughter cells
Receive the same amount of genetic material as the mother cell that produced them
Meiosis is when
A diploid cell produces a daughter cell that has a single set of chromosomes(haploid)
The cell cycle is defined as
The series of events that lead to cell division
Bacterial cells produce most cells via
Binary fisson
Cytogenetics
Field of genetics that involves the microscopic examination OF chromosomes
Karyotype
What have they let scientists discover about eukaryotic chromosomes
A photograph of chromosomes
That they occur in sets & that each set has 23 different chromosomes
Chromosomes are labeled by
Their size, with the largest ones having the lowest number
Sex chromosomes are designated by what instead of numbers.
Females=
Makes=
X or Y
XX
YY
Autosome, how many do we have?
Any chromosome that’s not a sex chromosome. We have 22 different autosomes
Most eukaryotic cells have ______ sets of chromosomes with ______ different chromosomes in each set for a total of ______ chromosomes per cell
2,23,46 per cell
Why do we have two sets of chromosomes
So we can inherit one set from
Mum and one from dad
Gametes are also called the ______ &_____ cells. They are ____ which means they have. ____ set of chromosome S
The sex cells, haploid , 1 set of chromosomes
In diploid cells the members of the pair of chromosomes are called —–. Which refers to ——- due to ——
Homologs.similarities due to common ancestry
Pairs of homologous chromosomes are evolutionarily derived from ——— so there are many similarities but they’re not identical due to ————
The same chromosomes, identical due to genetic changes over generations
Because each homologs is recieved from each parent, the 2 homologs might
Vary in the way that a gene affects a trait
Sequence of bases on one homolog differs from the other —–% of the time . So the DNA sequence on chromosome 1 that you got from mum is ——% likely to be——//
1%, 99% likely to be the same as the DNA sequence you got from dad
The slight difference in DNA sequence provide variation in
Gene function
A cell with 3 pairs of chromosomes is a —– and has
Diploid and has 3 chromosomes per set
Interphase account for what 3 stages?
G2, S, G2
Why would a cell leave the cell cycle and go into G zero phase
As an alternative to continuing through g1, it does this to postpone division, or in the case of terminally ill differentiated cells it does it because the cell is done dividing forever
G1 phase decides what
Depending on what
If it does decide to move forward it will
If the cell should divide, depending on cell environment and presence or lack of signaling molecules,make molecular changes to help progress through cell cycle
S phase
G1 has how many chromosomes
S phase has how many pairs of chromatids
Each chromosome is replicated to form a pair of sister chromatids 46,46
dna is synthesized
G 2 phase
Cell synthesizes the proteins necessary for chromosome sorting and cell division
M phase/ mitosis
Each cell nucleus is divided into 2 nuclei. The duplicated chromosomes are distributed so thy each new cell has the same complement of chromosomes
Cytokinesis
Usually follows mitosis, it’s the division of the cytoplasm to form 2 distinct daughter cells
Longest cycle to shortest cycle
G1, S phase, G2, m
Cyclins and cyclin dependent kinases are proteins responsible for what
Advancing a celll through the phases of the cell cycle. Kinases must bind to cyclins to be active
cyclins do what
Increases due to sufficient nutrients and growth factors. Binding to a CDK makes it Active and then it acts like a protein kinases&phosphorylatss proteins needed to advance cell cycle
There are 3 checkpoints in the cell cycle of eukaryotes in which proteins —-
Sense if the cells are in the proper condition to divide
G1 checkpoint; restriction point
Determines if conditions are good for division and check if the DNA is damaged. If damage is present proteins prevent formation of active cyclin/CDK complexes
G2 checkpoint
Checks for DNA damage again and checks that all the DNA has replicated
Metaphase checkpoint
Senses integrity of spindle apparatus and makes sure all chromosomes are attached to the spindle, which ensures chromosomes will stay correctly sorted during division
MPF
MaturTiok promoting factor, made of mitotic cyclin and a CDK
Mitotic cell division
When a cell divides to make 3 new indentical cells. Involves mitosis which divides nucleus into two nucli and involves cytokinesis, cytoplasm division
Mitotic cell division is important for —-/ which is a process where —— —— off spring are produced from. Unicellular organisms like —– and —– reproduce this way
A sexual reproduction, genetically identical , a single parent.bakers yeast and Amoeba
In preparation for cell division eukaryotic chromosomes are ——- and —— to —— —– called —- —-
Replicated and compacted, to produce pairs called sister chromatids
Sister chromatids are associated at a regional called the
Centromere
Centromeres serve as an —-/ —- for a group of —– that form the —–, which is essential for —–
Attachment site/ proteins/ kinetchore/ sorting each chromosome
The mitotic spindle is responsible for
Organizing and sorting the chromosomes during cell division
The mitotic spindle is made of
Microtubules, protein fibers that are components of the cytoskeleton in animals microtubules growth and organization starts at each centromere b
The central one in some Animal cells has ——// which are each made of
A pair of centrioles, 9 sets of triplet microtubules
Centrosomes make microtubules
By rapidly polymerizing tumbling proteins
Diploid
Haploid
2 homologous sets of chromosomes
Contains a single set of chromosomes
