Studied by 49 peopleGlobal climate change
local changes in average weather conditions occurring all over the world
Global Warming
the progressive increase of earth's average temperature over the last century
Anthropogenic global warming
Human caused global warming
greenhouse gasses
gasses that absorb and emit thermal energy
The greenhouse effect
atmospheric greenhouse gasses trap energy from the sun
Earth's atmosphere
insulating blanket of gasses including water vapor and carbon dioxide surrounding the earth
Mars
thin atmosphere of mostly CO2,(-58) degrees fahrenheit average temp at earth's south pole
Venus
super dense atmosphere, mostly CO2, (788) degrees fahrenheit, above melting temperature of lead
Earth
intermediate density 0/04% CO2, (59) degrees fahrenheit just right for us
What role does water vapor play in our current climate?
It helps keep the earth warm and habitable, and it responds to global warming caused by other factors
What are the contributors of the greenhouse affect?
water vapor, co2,ozone,methane,etc
Hydrogen bonds
attraction between neighboring water molecules
Heat
the total amount of energy associated with movement of atoms and molecules
temperature
measures the intensity of heat; how fast molecules move
Carbon Cycle
carbon flows between living organisms, the atmosphere, bodies of water, and rock
Carbon dioxide
absorbed by plants, algae and some bacteria, converted to carbohydrates with sunlight energy
What do bodies of water do with heat?
absorb and store it, resists temperature changes
9(humans)=4(atmosphere)+3(land plants)+2(oceans)
CO2 movement
Fossil Fuels
highly concentrated energy sources, made of ancient buried organisms (plants and microbes mostly)
How does fossil fuel use contribute to accumulation of atmospheric carbon dioxide?
petroleum, coal, and natural gas are burned for energy, releasing CO2
How do they measure CO2?
analyzing air samples, measuring PPM(parts per million) of CO2
Asexual Reproduction
one parent, offspring genetically identical to parent (in most cases)
Sexual Reproduction
genetic material from two parents combine, offspring are genetically different from one another and from the parents
DNA(deoxynucleic acid)
carries genes, section of DNA that codes for a particular trait
Genes
a basic unit of hereditary information
Chromosomes
made of DNA wrapped around proteins
Sister chromatids
copied chromosomes with the same genes
Where are sister chromatids attached?
attached at the centromere
When does DNA replication occur?
before cell division
semiconservative replications
how DNA replicates itself, a newly formed DNA strand, one half daughter
DNA Polymerase
enzyme that assists DNA replication
What do dark bands on chromosomes mean?
more DNA concentrated
During which phase of the cell cycle does chromosomal DNA replicate?
Interphase
Mitosis
asexual cell division produces two daughter cells that are identical to each other and the parent cell
What cells does mitosis occur in?
somatic (non sex cells)
Microtubules
tube shaped, provide structure and shape to eukaryotic cells, used for movement of chromosomes in mitosis
Centrioles
cylindrical organelle made of protein, involved in arranging microtubules
Poles
opposite ends of dividing cell
Nuclear envelope
membrane surrounding the nucleus is a phospholipid bilayer
Centromere
region (composed of a DNA sequence) that links a pair of sister chromatids
Interphase
DNA replicates
Mitosis
copied chromosomes moved into daughter nuclei
Cytokinesis
parental cell
Three phases of interphase
G1 (first gap or growth, cell grows), S (chromosomal DNA replicates), G2 (cell grows and prepares for mitosis
What is the order of mitosis? and what happens after?
prophase, metaphase, anaphase, telophase, end of mitosis , (cytokinesis), (Please Make Another Tiny (cell))
End of interphase
DNA has replicated but has not yet condensed into chromosomes
Prophase
chromosomes condense (into sister chromatids)
Metaphase
chromosomes align across middle of cell, moved by microtubules
Anaphase
centromeres split
Metaphase
nuclear envelopes reform around chromosomes in nuclei
Cytokinesis
NOT a stage of mitosis, division of cytoplasm
A cell undergoes mitosis and divides into two cells. One cell ends up with an extra chromosome, and the other cell has one less chromosome. At what stage would this error most likely have happened?
Metaphase and Anaphase
Cytokinesis in animal cells
band of proteins encircle cell at equator, proteins contract (like tightening a belt) and pinch apart the original cell into two daughter cells
Cytokinesis in plant cells
vesicles deliver materials for cell wall inflexible structure surrounding plant cells
Cellulose
fibrous carbohydrate proteins (used in cell wall), think plant cells/cell plate
Binary Fission
division of a single entity into two parts, a form of asexual reproduction
What performs binary fission instead of mitosis?
bacteria and archaea
Gametogenesis
production of gametes (genesis=production)
Gametes
specialized male and female reproduction cells
Meiosis
specialized cell division in sexually-reproducing organisms used to make gametes, occurs in gonads
Gonad
sex organ
Testes
in male
Ovaries
in female
How many chromosomes does a human somatic body cell have?
46 chromosomes
How many chromosomes do human gametes have?
23 chromosomes
Do homologous chromosomes always contain exactly the same genetic information?
No
What always contains the same genetic information?
Sister chromatids (exact copies of each other)
alleles
different versions of a gene
Tetrad
two sets of chromosomes that have been replicated into their sister chromatids
Human Chromosomes
displayed in magnified photograph arranged in 23 pairs by size
Autosomes
22 are non sex chromosomes
Haploid(n) cells:
contain one number of each homologous pair ex. gametes
Diploid(2n) cells
contain two sets of chromosomes, ex. zygote
Zygote
fertilized egg
Meiosis 1
separates the homologous chromosomes into two separate cells
Meiosis 2
separates the sister chromatids in each cell
Prophase 1
nuclear envelope breaks down, microtubules begin to assemble, chromosomes condense
Crossing over
exchange of information between homologous chromosomes, gametes can contain individual chromosomes with genetic information from both parents
Would crossing over create new combinations of alleles if it occurred between sister chromatids?
No, you’d get the exact same result on both sides
Metaphase 1
homologous pairs line up at equator, random alignment
random alignment:
members of homologous pairs are arbitrarily arranged go face a pole, results in genetically diverse gametes
Anaphase 1
Microtubules shorten, homologous pairs separate
Telophase 1
Nuclear envelope reforms around chromosomes
Cytokinesis
DNA is partitioned into each daughter cell, haploid cells
Is meiosis 2 the same as mitosis?
true
Prophase 2
Microtubules lengthen again
Metaphase 2
Chromosomes align at equator
Anaphase 2
Sister chromatids separate and move to opposite poles
Telophase 2
nuclei enclose each set of separated chromosomes
Cancer
disease that occurs when cells divide when they shouldn’t
How are cancer cells different from normal tumors?
Cancer cells invade surrounding tissues.
Tumor
a solid mass of cells with no apparent functions
Benign tumor
does not affect surrounding tissue
Malignant tumor
invades surrounding tissue; cancerous
Metastasis
a malignant cell breaks away and start new cancers at other locations
Cyst
fluid filled lump with no function, not cancerous
Henrietta Lacks
died of metastasized cervical cancer, cells from a tumor biopsy were used and cultured without consent,HeLa cells
HeLa Cells
one of the most important cell lines in medical research, immortal, reproduce indefinitely, recognition and consent to use the cells took a long time
Metastatic cancer cells
travel through body using circulatory(blood) or lymphatic system (lymph node)
Risk Factors for Cancer
behavior or conditions that increase the chance of developing a disease, inherited is carried in genes, environmental exposure can also impact
Note
Flashcard