This site is 100% ad supported. Please add an exception to adblock for this site.

rj biol - set#2

Terms

undefined, object
copy deck
main features that define life
organization of cells within organism, assimilation of carbon compounds through metabolism to gain energy, growth and reproduction of organisms, and, most essential, hereditary transfer of genetic material from one generation to the next during reproduction.
plasmodesmata
cell communication between plant cells
what is assessed at G1 checkpoint?
before entry into S phase (synthesis phase) cell growth is assessed at the G1 checkpoint. Here the cell decides whether it will divide or not.
Locus
Position of a gene on a chromosome - measured in centimorgans
what is multicellularity?
occurs in eukaryotes
evolution from single to multiple celled organisms. Allows for division of labour and specialized functions, enables organism to adapt to elements, mate, move around etc. allows for increased growth in size of organism. Contributes to enabling organism to better survive in environment.
mutation - frame shift
insertions or deletions, alter reading frame of DNA, effect: none, little, or drastic.
path of glycoprotein in a cell. Begin with synthesis and conclude with secretion
Free ribosome in cytoplasm. receives signal sequence. Docks on rough ER, manufactures the protein, transported through ER to golgi body, in golgi body, short sugar chains attach to protein to make it glycoprotein, gather in cisternae of golgi bodies, golgi contracts occassionally, pinches off capsule transport packages that are excreted from cell.
Importance of compartments in cell and example?
Lysosomes - organelles can contain enzymes which could kill the cell if not contained. Lysosomes are active in cells that destroy other cells, and active in cells that are in metamorphosis. Implicated in auto-immune disorders and aging.
what is an autosome?
the pair of chromosomes that make up the majority of the genetic code of an individual, whether male or female. Chromosomes that are not autosomes are the sex chromosomes, that determine gender of an organism.
prokaryotes versus eukaryotes - five differences
1. cell wall carbohydrate not plasma membrane 2. no organelles 3. rotating singular flagella - not 9+2 4. single circular DNA chromosome 5. very small compared to eukaryotes.
how does mitosis ensure the production of identical daughter cells?
no cross-over, centromeres divide.
syngamy
fertilization
what is parallel adaptation?
Adaptation is the process of developing features that increase an organisms ability to survive within a given environment. When two given environments are very similar but are geographically isolated and distant from one another, organisms within these environments often develop similar adaptations, because they are dealing with similar environmental conditions. This process is called parallel adaptation. The end result is similar organisms with similar adaptations, but who may be only distantly related.
How does the movement of chromosomes satisfy the requirements of mitosis and meiosis?
Mitosis: identical to parent, functions in repair and growth

Meiosis: independent assortmane and crossing over = genetic variation. Genetic repair - two chromosomes = template
how does meiosis ensure the production of haploid gametes?
only one homologue of each pair connected to microtubules in Meiosis I.
cell wall
Rigid structure outside plasma membrane in some plant and bacterial cells.
how do the consequences of mutations in germline cells and somatic cells differ?
Mutations in germline cells can be passed on to a subsequent generation; mutations in somatic cells cannot.
Why did Mendel's research succeed in clarifying the features of gene segregation among offspring where others had failed?
He used the same species, but he counted the numbers of offspring in succeeding generations.
why is crossing over important?
mixes parental alleles.
types of eukaryotes with chloroplasts?
algae and plant photosynthetic cells. Perform photosynthesis.
what are lysosomes an illustration of?
compartmentalization into organelles is crucial to maintaining cell function. (Enzymes could destroy cell if allowed to escape from lysosome.)
mitochondrion
tubular organelles, smooth outer structure, inside many folded layers - cristae, divide the mitochondria into two compartments inside:matrix, outside - intermembrane space where proteins reside, carry out oxidative metabolism - stores energy in macromolecules. (Adenosine Tri-Phosphate or ATP)
why is sexual reproduction such an important evolutionary advantage?
allows for inclusive fitness, rapid recombinations of genetic material so great that some of the variations produced in a changing environment will be likely to survive. Also, DNA reparation made possible, by use of homologous chromosomes as templates.
Dihybrid cross
Follows the inheritance of two genetic traits through three generations
about how many genes are there that can be mutated to cause cancer? why do most cancers require mutations in multiple genes?
Mutations in very few genes actually cause cancer, but it is the mutation in those genes that regulate cell-cycle check points that can be devastating in any kind of cancer. Since there are usually several check points regulating cell division, however, development of cancer would require mutations in the genes for each check point, or mutation of multiple genes.
mutation - how cells protected?
avoidance of mutagens
2 genetic copies (backup and repair)
many cells in an organism
what is assessed at M1 checkpoint?
where mitosis is assessed at metaphase. Passing the M checkpoit indicates an exit from mitosis and beginning of G1 major growth cycle.
haploid
one set of chromosomes
adaptive radiation
divergence of species from a common ancestor through the occupation of different habitats in a given area. Physical, physiological or behavioural adaptation to the different environmental habitats within the area eventually causes the speciation.
Nucleosomes made of? Participate in DNA coiling how?
complex of eight positively charged histone proteins, making a form that strongly attracts negatively charged DNA phosphate groups, causing them to coil tightly around the nucleosomes. These then coil further into supercoils.
gene
sequence of nucleotides that codes for a particular protein to pass along genetic information from one generation to the next, and define the physical traits of an individual.
Phenotype
Outward expression of genotype
cellular products of meiosis?
Haploid or diploid?
Haploid daughter cells
Cilia -difference from flagella?
More numerous. Not just for locomotion - also move fluids over tissue surfaces and aid in sensory input.
what is incomplete dominance?
not all alternative alleles are fully dominant or recessive in heterozygotes. Sometimes heterozygous individuals do not resemble one parent precisely. Some pairs of alleles instead produce a heterozygous phenotype that is either intermediate between the parents (incomplete dominance), or representative of both parental phenotypes (co-dominance).
DNA=
Chain of chemical units called nucleotides
what is genetic recombination? what three mechanisms are responsible for producing it? which of these mechanisms occur in prokaryotes and which occur in eukaryotes?
Genetic recombination is the change in the chromosomal position of a gene or a fragment of a gene. The three kinds are (1) reciprocal recombination, wherein two chromosomes trade segments; (2) gene transfer, wherein one chromosome donates a piece to another; and (3) chromosome assortment in meiosis. All occur in eukaryotes, but only reciprocal recombination also occurs in prokaryotes.
Nucleolus - does what?
manufactures ribosomal sub-units and holds genetic material
what is a mutation? What is a point mutation?
A mutation is a change in the genetic message, usually involving the alteration of DNA. If one or a few nucleotides are altered, it is called a point mutation.
RNA bond
C-G (triple bond)
A-U (uracil - double bond)
(Instead of thyamine as in DNA)
what is a polymorphism?
occurrence of two or more distinct forms within a species. i.e. males and females, eye colour in humans, Polymorphism is illustrated in bees, as workers, drones, and queen bees are distinct forms within the same species. These occur more frequently than could by mutation alone.
golgi complex - function
delivery system for eukaryotic cell, collects, packages, modifies and distributes molecules synthesized at one location to be used in another.
what is transfection? What has it revealed about the genetic basis of cancer?
In transfection, DNA is removed from a cancer cell and chopped up into pieces. Each piece is then inserted into a cell to see which piece is actually responsible for causing the disease. This technique has shown that genes involving regulation of cell division (mitosis) are responsible for the development of tumors.
3 binding sites in RNA
A-Aminoacyl tRNA binding site
P-Peptidyl tRNA binding site
E-exit site
how do proto oncogenes differ from tumor-suppressor genes in the mechanisms by which they lead to excessive cell proliferation and cancer?
Proto-oncogenes are normal genes that code for frequent cell division and as such, if mutated, could become overexpressed and code unchecked for cellular duplication leading to cancer. Tumor-suppressor genes are also normal genes that code for suppression of cell division. Should a tumor-supressor gene become mutated, unchecked cellular division may result.
What is autosomal linkage?
When two or more alleles occur on the same chromosome, they are said to be linked. If the chromosome that these alleles occur on is an autosome, they are said to be autosomally linked. If alleles occur on a sex chromosome, they are sex-linked. Colour blindness is an example of a sex-linked trait.
cytoskeleton
structural support and cell movement
why would some organisms capable of sexual reproduction still use asexual reproduction?
organisms living in harsh environments have adapted ways of surviving within those environments. Creating progeny that is genetically identical using successful gene combinations through asexual reproduction may help to ensure the survival of the species.

Conversely, if an organism capable also of asexual reproduction chose only to reproduce sexually, there would be no guarantees that the progeny produced would survive. The random, and thus unpredictable, genetic combinations produced by sexual reproduction would produce random predictability of survival within the harsh environment.
diploid
two sets of chromosomes
bottleneck effect
random genetic sample of population drastically decreased in size by an event
cell structure?
cytoplasm - semi fluid matrix
bounded by membrane - plasma membrane (separates them from environment). Contain genetic information, encoded in DNA molecule, which directs activities. In prokaryotes, DNA is in central portion of cells. In eukaryotes, in nucleus (subcellular organelle) surrounded by double membrane called nuclear envelope.
mutation - causes
radiation, smoking, xray, uvlight, asbestos, formaldehyde, etc...
Alleles
Different forms of a particular gene
nuclear envelope
surrounds hereditary apparatus
microbodies
contain catalase, an enzyme which breaks down hydrogen peroxide into water and oxygen. (Sometimes called peroxisomes.)
mutation - base substitution
replacement of one nucleotide with another. effect depends on nucleotide: none, little, or drastic.
gametes
eggs and sperm
Cellular product of syngamy? Haploid or diploid?
Diploid Zygote.
somatic
non reproductive cells
what types of organisms capable of asexual reproduction? How do they differ from those produced via sexual reproduction with respect to parental similarity?
bacteria, prokaryotic cells, some lizards, and plants. All are genetically identical to parents.
Monohybrid cross
Follows pattern of inheritance of a single characteristic through three generations.
DNA bonds
C-G (triple bond)
T-A double bond
How is cytokinesis different in animal and plant cells?
In animal cells, cytokinesis occurs via an actin filament drawing inwards like a drawstring to pinch the daughter cells apart. In plants, a cell plate forms from the inside out, eventually dividing the daughter cells. Plant cells can't use an actin filament because the cell walls are too rigid.
Mitochondrion replication
impossible without nuclear participation: cells don't produce new mitochondria when cell divides, so mitochondria divide, thus doubling, and are then divided equally between daughter cells.
Parthenogenesis - define. How does it differ from other forms of sexual reproduction?
development of an adult from an unfertilized egg, common in arthropods. In bees, fertilized eggs become diploid female queens, but unfertilized eggs are haploid male drones. Lizards, some fish and amphibians also produce progeny via parthenogenesis. The eggs undergo mitotic division as if they were a diploid zygote.
Shapes of prokaryotes? 3
cocci - round
baccilli - ovoid
spirilla - spirally.
Genotype
actual genetic complement
chromatin
"loose" chromosomes
start codon?
AUG
ribosomes
site of protein synthesis
phylogeny
evolutionary history of a species as a whole
pili
hair like surface appendage, functions in adherence and transfer of DNA during conjugation.
Genetic disorders: Klinefelter syndrome. genotype and symptoms.
XXY zygote
- develops into sterile male
- many female body characteristics
- diminished mental capacity
- 1/500 male births.
heterozygous advantage
When a heterozygote is able to cope with a given condition better than a homozygous dominant individual for a given homozygous recessive condition)
Muellerian Mimicry - what is it and what are the most common strategies?
In Mullerian mimicry, several unrelated but usually dangerous or unpalatable organisms come to resemble each other, such as wasps and other stinging wasplike insects, gaining "safety in numbers" when the intelligent predators avoid them all as a group. These groups of organisms are typically equipped with bright warning colors, such as red or yellow.
DNA vs. RNA
Deoxyribose versus ribose sugar

RNA =one strand, DNA = two.

Base pairing different (RNA A:U, not T)
tumour supressor genes
normally stop cell division, but if mutated can cause cancer.
nucleotide comprised of:
sugar molecule (deoxyribose) + phosphate + a nitrogenous base (adenine, thyamine, cytosine or guanine)
What is Pleitropic effect?
Where an allele can have more than one effect on an individual's phenotype, e.g. the recessive allele that causes cystic fibrosis produces diverse pleiotropic effecs such as thick mucous that clogs the lungs, liver, and pancreas, as well as salty skin.
TRNA
interpreter,
translates mRNA,
unpaired bases are at bottom in anticodon region,
unique shape
sustainable development - problem solving
The goals at environmental science are operational ones-to solve the problems created by modern society's impact on the environment. Eliminating pollution, conserving biodiversity, protecting groundwater and topsoil-these are but a few specific goals. The tools environmental scientists use are Ecology, Geology, Political Science, and Economics; environmental problems typically impact a broad range of scientific and social issues. The five components to solving environmental problems are assessment, risk analysis, public education, political action, and follow-through.
capsule
protective outer layer that aids bacteria in remaining hidden/antibiotic resistance.
Law of independent assortment
Individual gene pairs are inherited independently of each other (i.e. corn kernel colour vs. texture.)
ribosomes do what, and come from where?
direct protein synthesis by reading an mRNA copy of gene. Individual small and large sub-units of ribosomes synthesized in nucleolus and move through nuclear poles to cytoplasm and assemble there.
autosomal vs. sex-linked
autosomal traits can express on any chromosome, vs. sex linked - sex determined traits on Y chromosome
how are chromosomes distinguished from one another in a chromosome?
size and position of centromere and composition.
3 stages of Amino Acid Construction
1. INITIATION -
mRNA joins small subunit of ribosome
initiator tRNA base-pairs with start codon AUG
large ribosomal subunit comes along
tRNA vacates A site, moves to P site

2. ELONGATION -
ribosome moves along chemical chain, tRNA adding amino acids to chain via peptide bonds

3. TRANSLOCATION -
ribosome moves along until termination at UUA, UAG or UGA
Epistasis
Interactions of the products of different genes. (clover producing cyanide).
What barriers exist to the formation of hybrids? Which are prezygotic and which are postzygotic isolating mechanisms?
Geographical, ecological, temporal, behavioral, and mechanical isolations exist to the formation of hybrids. Prezygotic mechanisms prevent gamete fusion; postzygotic mechanisms involve embryo developmental failure or abnormalities. explanations on p504-505
microevolution
the progressive evolutionary change taking place within populations
Three examples of natural selection
1. sickle cell anaemia: where lots of malaria, more of this gene as it allows individuals to survive when they are heterozygous for the gene. They also don't exhibit symptoms.
2. British Peppered moth - were light coloured before industrial revolution, but are now dark coloured to adapt to changed tree colour. (Camoflage for moths, trees darker due to soot from industry.)

3. Bent grass in Wales - individuals tolerant of high concentrations of lead lived, passing on this trait such that now the only individuals living on the mine tailings are lead tolerant.
ecology
study of relationships of organisms to their environment
Six pieces of evidence that support the idea that some organelles of eukaryotes were once free-living prokaryotic cells.
1. Mitochondria and plastids contain DNA like prokaryote chromosomes
2. Mitochondria and plastids divide independently of their "host" cells
3. Mitochondria and chloroplasts contain their own ribosomes
4. symbiosis does occur between bacteria and eukaryotes
5. Electron transport chains in chloroplasts are identical to photosynthetic bacteria
6. the double membrane of chloroplasts and mitochondria could have arisen by one cell engulfing another cell.
hardy weinberg -
equation and conditions
P2+2pq+2q2=1
1.Must be random mating (not based on genotype - no eugenics!)
2. Isolation - allele frequencies not changing because of migration in or out
3. Large population - reduces genetic drift
4. No mutation
5. No selection - individuals should be equally well-equipped to cope with environment, and equally fertile.
sustainable development - why is loss of biodiversity important?
First, we have no ethical, moral, or aesthetic right to decimate such valuable communities. Second, the organisms comprising diverse ecosystems give us everything we have: food, medicines, clothing, shelter. It is stupid to eliminate the source of many of our needs. Third, the biotic and abiotic components of an ecosystem interact. Without the biotic (living, organismal) component, the abiotic (nonliving: water, rocks, soil, nutrients, etc.) will become inexorably altered as their biotic components are decimated to consequences we can't even predict in some cases.
biological magnification
The process by which concentrations of chemicals which can't be broken down, such as DDT, are transferred from one trophic level to another, concentrating within the tissues of the organisms at each level.
thermocline
abrupt zone where change in temperature occurs in lakes in the summer, between the warmer upper epilimnion and the cooler low down hyponlimnion.
ratio given by a monohybrid cross?
1:2:1
oncogenes
tumor inducing genes. Normally turned on during development, but off as differentiation begins. Carcinogens can turn oncogenes on and cause cells to become cancerous.
Type of cells that form gametes?
Germline cells
karyotype
array of chromosomes that an individual possesses
macroevolution
appearance and disappearance of whole groups of living organisms over long periods of time
Genetic disorders: cystic fibrosis
- thickened mucal secretions
- clogging of lungs, pancreas, & liver.
1/1800 children
- caused by faulty regulatory system for chloride ions across membranes.
- salty skin is characteristic.
darwins finches are an example of what kind of reproductive isolation mechanisms?
ecological, bahavioral, and probably mechanical and prevention of gamete fusion. Probably also post-zygotic mechanisms acting...
Batesian mimicry - what is it and what purpose does it serve?
Batesian mimicry describes the situation when an unprotected species evolves to resemble a chemically protected species. The purpose for the possessor is that it will not be preyed upon by those predators familiar with the model.
what is the primary mechanism that maintains the integrity of the species clusters in the of Drosophila in the hawaiian islands?
Behavioral isolation
epilimnon
warm surface layer of lakes in summer
Law of segregation
During meiosis, homologous pairs of chromosomes separate into different cells.
How did endoplasmic reticulum and Golgi apparatus evolve:?
Invagination of plasma membrane of prokaryote.
Hierarchy of Classification system?
Kingdom
Phylum
Class
Order
Family
Genus
Species
organism (in evolutionary terms)
Is the result of the environments experienced by its ancestors.
What are biogeochemical cycles, what are the primary reservoirs for the chemicals in these cycles, is there a greater amount of life-sustaining chemicals in these reservoirs or in the whole of the earths living organisms?
Biogeochemical cycles are geological cycles that involve the biologically controlled cycling of chemicals. Chemicals are generally stored in the atmosphere, water, and rocks in these cycles. There is much more of the life-sustaining chemicals in these reservoirs than in organisms.

Deck Info

112

permalink