Biology Flashcards
What is connective tissue?
Provide support/framework for epithelial cells; blood, bone, cartilage, tendons, ligaments, adipose tissues
What are the three main parts of Darwin’s Theory of natural selection?
- Organisms produce offspring of few survive. Chance variations within populations are heritable.
- If the variation increases an organism’s survival chances, the variation is termed favorable.
- These individuals will have greater fitness (reproductive success) and fitness is directly correlated to organism’s genetic contribution to the next generation.
What are the layers of the skin?
Epidermis, dermis, hypodermis
What are the layers of the epidermis?
Corneum (dead skin cells, protection
Lucidum (thick, hairless, hells of palms)
Granulosum (keratonocytes die)
Spinosum (langerhancells, macrophages, present antigens to T- cells)
Basale (stem cells=> keratinocytes; melanocytes –> skin color)
What are the layers of the dermis?
Papillary- loose connectice tissue
Reticular- hair follicles, sweat glands, blood vessels
What does the hypodermis contain?
Fat = connective tissue
What are the sensory receptors of dermis?
Merkel- deep pressure + tecture
Pacinian- deep pressure + vibration
Meissner’s - light touch
Ruffini- stretch
Where is the electron transport chain located in prokaryotes?
Plasma membrane
What is the molecular weight of an amino acid?
110 Da
What is commensalism?
one benefits; the other doesn’t but doesn’t harmed either
What is mutualism?
mutually dependent
What is parasitism?
one benefits; the other is harmed
What is senescence?
biological aging in which cells no longer replicate (shortened telomeres)
What does the ectoderm form?
epidermis, NS, adrenal medulla
What does the mesoderm form?
dermis, musculoskeletal system, circulatory system, adrenal cortex
What does the endoderm form?
epithelial lining of GI and resp systems
What is induction?
The release of factors that promote differentiation in other tissues (can be reciprocal)
What cells produce myelin in the CNS?
oligodendrocytes
What cells produce myelin in the ONS?
Shwann cells
upstream and downstream a gene
upstream is before the gene; downstream is after the gene
osteoblast
bone-forming cells (build)
osteoclasts
bone-resorbing cells (breakdown)
vasoconstriction
increases blood pressure but decreases oxygen delivery to those tissues
perfusion
the movement of fluid through the circulatory or lymphatic system, specifically the delivery of blood to capillary beds in tissues
Myosins
hydrolyze ATP to power sarcomere contract
Microtubules
Kinesins and Dynenin; motor proteins involved in intracellular transport; deliver vesicles along MT’s (kinesins towards + and dyneins toward -)
Eukaryotic cell membranes only have fatty acids with
1) and even number of Carbons
2) only CIS double bonds (NO TRANS AT ALL)
each cytochrome c molecule carries
1 electron for it’s one heme molecule
Primers suitable for PCR have
a high GC content and G and C base pairs at the ends
Nondisjunction
failure of homolog chromosomes to separate in Anaphase I or sister chromatids to separate in Anaphase 2
Microfilaments
actin
Intermediate filaments
keratin, lamins, cell-cell adhesion, anchors
What is convergent evolution?
When distantly related organisms independently evolve similar traits to adapt to similar needs.
Gene operons in prokaryotic cells
are transcribed from a single promoter upstream the operon and DON’T undergo splicing
Imprinted gene
genes expressed in a parent-specific manner
What is a silent mutation?
Has no effect on protein
What is a missense mutation?
Amino acid substitution
What is a nonsense mutation?
Early stop codon
What is the start codon?
AUG = Methionine
What are the stop codons?
UAA, UGA, UAG
What is a chromosomal duplication mutation?
A segment of DNA is copied multiple times
What is a chromosomal deletion mutation?
large segment of DNA is lost
What is penetrance?
The proportion of population with a certain genotype who actually express the phenotype.
What is expressivity?
The diff phenotypic manifestations of a genotype across the population.
Fecundity
How easily and frequently and organism can produce offspring.
Natural Selection vs Group Selection
natural is selection until reproduction where as group is selection after reproduction (grandparents help raise grandkids)
Genetic Drift
composition of gene pool changes due to random chance small populations
Bottleneck effect
major disaster or event that kills off a large part of the population (extreme form of genetic drift)
Founder effect
results from bottlenecks that suddenly isolate a small population, leading to inbreeding and increased prevalence of certain homozygous genotypes and less variation in the genotype
Divergent evolution
occurs when two species share a common ancestor become more different
Parallel evolution
occurs when two species share a common ancestor evolve the same way
Convergent evolution
occurs when two species not sharing a recent ancestor evolve to become more similar due to analogous selection pressure
Punctuated Equilibrium
considers evolution to be a slow process with intermittent rapid bursts of evolutionary activity
recombinant frequency
the likelihood of two allele being separated during crossing over in meiosis
Hardy-Weinberg principle
if a population meets certain criteria (aimed at lack of evolution) then the allele frequencies will remain constant
Reproductive isolation of species: prezygotic mechanisms
temporal (mating season) ecological (different niches) behavioral (lack of attraction) reproductive (parts don't match up) gametic (intercourse but no fertilization)
