Chapter 8 9 Flashcards
asexual reproduction
DNA is a single, circular chromosome attached to the membrane
parent cell divides in half
offspring are genetic replicas of the parent cell because all chromosomes come from a single parent.
sexual
requires fertilization of an egg by a sperm
somatic
any cell except the egg and sperm cell
cells are produced by mitosis for growth and maintenance
gametes
egg and sperm cells
produced by meiosis
histones
proteins
nucleosomes
eukaryotic DNA wrapped around histones
telomeres
end tips of DNA
interphase
cell growth and preparation to divide
G1 (gap 1)
cell growth and maintenance
takes 12 hours
neurons and heart cells spend most of their time here
G1 (gap 1)
cell growth and maintenance
takes 12 hours
neurons and heart cells spend most of their time here
synthesis (S)
every chromosome is copied by replication
before replication chromosomes are long and linear
takes about 6 hours
DNA polymerase
adds complementary nucleotides to each template
proofreads
corrects mistakes
G2 (gap 2)
growth continues preparation for division
shorter than G1
takes 6 hours
mitotic phase
cell division: nucleus of parent cell duplicates followed by the cytoplasm and plasma membrane
cytokinesis
separation and duplication of organelles,cytoplasm, cell membrane
takes 30 minutes including the other parts of the mitotic phase
cell splits in two
Apoptosis
programmed cell death
prophase
preparation
nuclear membrane breaks down, sister chromatids condense, spindle fibers form
metaphase
middle
sister chromatids line up in the middle of the cell
anaphase
apart
sister chromatid pairs are pulled apart by spindle fibers
telophase
two nuclei
chromosomes uncoil as nuclear membrane is reassembled
cancer cells
unrestrained cell growth and division caused by disruption on DNA to regulate division
second cause of death
how does cancer cause cell death?
pressure on neighboring cells and disruption of vital processes
benign
cell mass that does not spread
malignant
cells spread through circulatory system
cancer cell treatmen
surgical removement or kill/slow down cell division
cancer cell treatmen
surgical removement or kill/slow down cell division
side effects of cencer
reduced red blood cells shortness of breath and fatigue reduced platelets and white blood cells increased bruising and infection hair loss
diploid cells
have two copies of each chromosome
haploid
only one copy of each chromosome
benefits of sexual reproduction
genetic variation through:
- crossing over
- random re-assortment of homologues
- alleles come from two parents
- random fertilization
down syndrome
syndrome caused by non-disjunction of chromosome 21`
abnormal number of sex chromosomes
Turner Syndrome
Klinefelter Syndrome
“Super Males”
“Meta Females”
Heredity
refers to the greater resemblance of offspring to parents than to others in the population as a consequence of passing over of traits from parents to offspring through their genes
genetics
the study of the mechanisms of heredity
single-gene traits or Mendelian inheritance
traits carried in one gene
Law of Segregation
during the formation of gametes, the 2 alleles for a gene separate from each other during meiosis
homozygous
same 2 alleles for a gene
heterozygous
different alleles for a gene
Mendel’s Law of Independent Assortment
homologous chromosomes separate independently from each other during meiotic division
dihybrid cross
parental variteties based on 2 characteristics or traits, rather than one
human disorders controlled by a single gene
autosomal genetic disorders
x linked genetic disorders
autosomal genetic disorders
Tay-Sachs disease
Huntington’s disease
x linked genetic disorders
red green colorblindness
hypertrichosis
pedigrees
tools used by geneticists to decipher and predict the inheritance patterns of genes
incomplete dominance
heterozygous looks intermediate between 2 homozygous
codominance
heterozygous shows both traits
multiple allelism
a single gene has more than two alleles
polygenic inheritance
one trait influenced by many genes
pleiotropy
one gene influences many traits
sex-linked traits
gene responsible for producing proteins that distinguish red and green wavelength in the sex chromosome
enviornmeental effects
genes interact with the environment to produce physical characteristic and thus environment variation influences the expression of genes
amniocentesis
test of amniotic acid fluid using a needle and ultrasound
chorionic villus sampling
transcervical or transabdominal sampling of vili
