Why do cells reproduce themselves?
for acquisition of new resources and protection of their obtained resources
Cells and organisms are in constant state of renewal to..
produce greater numbers of themselves
create variation within the population
How many chromosomes do human cells have?
46
How many chromosomes do eukaryotes have?
10-50
Chromosomes
strands of DNA in a cell or organism along with proteins that organize and regulate the activity of genes
Gene
sequence of DNA that encodes the information to produce one protein
How is DNA replicated?
the two strands need to be separated/opened
What is the enzyme that replicates DNA called?
DNA polymerase
DNA is synthesized using what template?
synthesized 5' to 3' using the template that is 3' to 5'
Replisome
A number of enzymes that act together to replicate DNA
Ultraviolet Light UV causes
Thymidines next to eachother to form covalent bonds
cancer
excision repair
one way to repair DNA lesions
Xeroderma pigmentosum
Genetic disease that makes the effected individual more sensitive to UV damage due to a defect in one of the seven genes
chromosome condensation
keep the chromosome organized and make it compact and easy to handle during cell division
S (interphase)
The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.
G1 of interphase
Cell growth
G2 of interphase
Cell prepares to divide
Interphase
chromosomes not condensed
Prophase
chromosomes condense
Centrioles separate
Early Metaphase
Nuclear membrane breaks apart
Spindle is produced form centrioles
kinetochore connects microtubules to centromers
Metaphase
Chromosomes line up in the middle
spindle- kinetochore microtubules fully connected to centromeres
Anaphase
Spindle microtubules contract taking one sister chromatid of each chromosome to each daughter cell
Telophase
Cytokinesis
Cytokinesis
division of the cytoplasm
end goal of mitosis
2 daughter cells identical to mother cell
can you have mitosis without cytokinesis?
Yes
mitotic regulation
regulatory proteins at cell cycle 'check points' stop progress unless they get the appropriate signal
mitosis
division of the nucleus
Cytokines
division of the cytoplasm
asexual reproduction
identical offspring
slow evolutionary changes
Sexual reproduction
offspring genetic remixes
fast evolutionary changes
Meiosis
Process of cell division which produces haploid gametes
Homologous
similar but not identical
haploid number (n)
indicates the number of distinct types of chromosomes present
Ploidy
indicates the number of each type of chromosome present
meiosis I (reduction division)
homologous chromosomes pair in prophase I and one of each pair is pulled into each daughter cell
Each daughter has half the chromosome number of parent
Meiosis II
Each daughter cell from meiosis II has same # of chromosomes as parent cell. Each daughter cell has half test DNA as the sister chromatids for each chromosome seperate
Crossing over
when chromosomes are lined up in metaphase I and regions of one chromosome swap with the similar region on the homologous chromosome
crossing over is also known as
two chiasma or X spots
Downs syndrome
result of an extra chromosome
Principle of Independent Assortment
states that genes are distributed to the next generation independently of eachother
Mendels laws
1. Law of Segregation
2. Law of independent assortment
3. Law of dominance
A trait is produced by
the expression of a gene or a number of genes
Alleles
Different versions of a gene located at the same spot on different homologous chromosomes
Dominant
An allele that is always expressed
Recessive
An allele that is masked when a dominant allele is present
beak
Morphological trait
Heredity
patterns of how traits are passed on to the next generation
Traits
determined by the DNA they contain
controlled by presence of a single allele
BB and bb are..
homozygous
Bb is..
heterozygous
Law of Segregation
during the formation of gametes, alleles responsible for a trait separate one to each gamete; this allows for recombination during fertilization
Law #2- The Law of Segregation
If you follow the inheritance of more than one gene they assort independently
incomplete dominance
one allele is not completely dominant over the other
quantitative traits
Traits do not behave as predicted by the sorting of a single or even two or three genes