midterm 1 Flashcards
What is science
The observation, identification, experimental investigation, and theoretical explanation of natural phenomena
What is the “scientific method”
standard approach practiced by scientists
Define “Evolution”
Heritable change in a population of organisms from generation to generation
Define “Structure and function”
Structure determines function
Define “Energy and Matter”
Energy is acquired from the environment and used to make molecules & maintain an organisms body
Define “Systems”
Interactions between parts create novel structure or fun actions, leading to emergent properties
What is the process of doing biology
Observations Hypothesis Experimentation The Data Conclusion
What is a hypothesis
A proposed explanation for a natural phenomenon. Based on previous observation, testable, falsifiable, not something you can prove
What is a theory
A broad explanation of some aspect of the natural world, backed by extensive evidence
What is the peer- review process
Scientist, Journal editor, reviewer
What Job does the journal editor have in a peer review process
He will either reject or accept it
What job does the reviewer have in Peer review process
To find any. gaps in reasoning and to ensure that nothing has been overlooked
Who was Charles Darwin
Proposed that all species of life descended from a common ancestor, and developed the theory of natural selection
What is natural selection
Existing species result from modifications. Traits that favour reproductive success become more common in a population over time
What is “Variation in traits”
Heritable traits passed from parent to offspring
What is a mutation
Heritable change in genetic
Where is most of the DNA in the cell
the nucleus
What is vertical descent
Genetic material (DNA) passed down across generation, Occurs within lineage
What is horizontal gene transfer
Genes transferred between organism. E.G antibiotic resistance
What are cells
simplest functional unit of a living organism
What was the cell theory (mid 1800s)
All living organism are composed of one or more cells. Cells are the smallest unit of life. New cells come from pre-existing cells by cell division
What is the difference between RNA and DNA
RNA is single stranded and has a single nucleobase
What are the cell types (general)
Prokaryotic, animal. plant, eukaryotic
What is chromatin
DNA + histones
What are histones
Proteins that support the DNA
What is the difference between prokaryotic and eukaryotic cells
Prokaryotic cells lack internal compartmentalization, does not have a membrane enclosed nucleus
What does the Rough ER
Proteins packaged into membrane vesicles
What type of proteins are synthesized through the RER
Ribosomes/RNA
What does the Smooth ER do
Detoxification, calcium storage
What does the Golgi Complex do
Processing, modification, sorting and secreting molecules produced in that cell. Passed out of the cell at the cell membrane
What does the cell membrane do
Transports proteins, gasses, and mechanisms in and out of the cell. Semi permiable
what is ACE-2 receptor
A protein complex in the plasma membrane
How does a virus first enter the cell
Binds to ACE-2 receptors, flows together with the plasma membrane and welcomes it to the host cell
What does the mitochondria do
Supplies the cell with ATP
What does a chloroplast do
Photosynthesis< captures light energy and makes glucose
What is cytosol
Site of many metabolic pathways, breaks down complex molecules like proteins, lipids, carbohydrates
What does the cytoskeleton do
Protein filaments that provide shape and aid in movement
What Is chromatin
A complex of protein and DNA
What does the nucleolus do
Site for ribosome subunit assembly
Where is the DNA located in a prokaryotic cell
Nucleoid region
What is “cytogenetics”
The cytological approach to genetics, mainly involving microscopic studies of chromosome
What is Transmission Genetics
The study of the mechanisms involved in the passages of genes from one generation to the next
What is Population Genetics
The study of variation at the genetic level among a group of individuals
What is quantitive trait genetics
A quantitive trait is a measurable trait that shows continuous variation and cannot be classified into a few discrete classes
What is molecular genetics
The study of the molecular processes underlying gene structure and function
What is Epigenetics
The study of changes in organisms caused by modifications of gene expression rather that alteration of the genetic code itself
What are the four criteria necessary for genetic material
Information
replication
transmission
variation
What are nucleotides
The building blocks of DNA and RNA
What is a double helix
Th two strands of DNA
What is a genome
the complete complement of genetic material in an organism
What is central dogma
Replication(DNA)
Transcription(DNA to RNA)
Translation (RNA to proteins)
What do the other 22 pairs of chromosomes determine and what are these pairs called
Autosomes, and the determine Things like hair and colour or our eye colour
What are chromosomes made out of
Genes that carry genetic information, which are made of a sections of long molecule called DNA
What are diploid pairs
Humans have 23 pairs
What are haploids
gametes have One copy of each chromosome
What are the three phases of interphase of mitosis
G1, S phase and G2 Phase
What happens in G1 phase
G1: Cell growth occurs. if the cell passes the restriction point (G1 checkpoint) it is committed to enter S phase
What happens in S phase
Chromosome replicates, Two copies stay joined to each other and are called sister chromatids
What happens during G2 phase
Cell synthesizes proteins needed during mitosis is and cytokinesis
What makes a cell decide to divide
Environmental conditions, signalling molecules
Cell cycle control molecules
checkpoints
What are checkpoint proteins called
cyclins or cyclin dependant kinases
What are cyclins or (cdks) do
They are responsible for advancing a cell through the phases of the cell cycle
What are the three checkpoints in Eukaryotes
G1,G2,metaphase checkpoint
What are chromatids
Identical copies of DNA associated proteins
Where are chromatids associated (location)
nucleus
What is the kinetochore
the location where the two chromatids attach making the centromere of the chromosome
What does the mitotic spindle do
Ensures that each daughter cell will obtain the correct number and types of chromosomes
What is a mitotic spindle responsible for
for organizing and sorting the chromosomes and is composed of microtubles
How is a spindle formed
by microtubules
What are the three types of microtubules
Astral microtubules-position spindle in cell
Polar microtubules- separate two poles
Kinetochore microtubules-Attached to kinetochore bound to centromeres
What is Interphase
Phase of cell cycle during which the chromosomes are decondensed and found in the nucleus (G1, S, G2)
What are the phases in Mitosis
Prophase Prometaphase Metaphase Anaphase telophase
What is cytokinesis
After the mitosis cell cycle, it is the division into the two daughter cells
What happens during prophase
Chromosomes have already replicated and are joined as pairs of sister chromatids. Chromatids condense into highly compacted structures
What happens during prometaphase
Nuclear envolope completely fragments
Mitotic spindle forms
What happens during Metaphase
Pairs of sister chromatids are aligned along a plane halfway between the poles called the metaphase plate
What happens during Anaphase
Connections broken between sister chromatids. Each individual chromatid is linked to only one pole by kinetochore microtubules
What happens in telophase
Chromosomes have reached their respective poles and decondense. Nuclear membranes now re form to produce two separate nuclei
What is mitosis always followed by
Cytokinesis
What is the cytokinesis process called for an animal cell
Cleavage furrow
what is the cytokinesis process called for a plant cell
Cell plate awl forms
What is Meiosis
The process by which haploid cells are produced from a cell that was originally diploid
What are the two differences in Meiosis and Mitosis
Homologous pairs from bivalent or tetrad
Crossing over
What happens when bivalent forms
When two pairs of sister chromatids stick together, this happens before crossing over occurs
What are the phases of meiosis
Prophase 1 Prometaphase 1 Metaphase 1 Anaphase 1 Telophase 1 Cytokinesis End of meiosis 1: two haploid cells All of the above but round two
What happens in prophase 1
Chromosomes condens, bivalents form
What happens in pro metaphase 1
Spindle apparatus complete, chromatids attach to kinetochore microtubles
What happens in metaphase 1
Bivalents organized along metaphase plate as a double row
What happens in anaphase 1
Segregation of homologs occur, chromatids migrate to one poles, while homologous pair moves to opposite pole
What happens in Telophase 1 an cytokinesis
The chromosomes decondense and the nuclear envelope reforms.
What happens in prophase 2
Sister chromatids condense, and the spindle starts to form. the nuclear envelope begins to dissociate into vesicles
What happens in pro metaphase 2
The nuclear envelope completely dissociates into vesicles. Sister chromatids attach to the spindle
What happens in Metaphase 2
Sister chromatids align along the metaphase plate, each pair of sister chromatids is attached to both poles
What happens in anaphase 2
Sister chromatids separate and individual chromosome move toward the poles as kinetochore
What happens in telophase 2
Chromosomes decondense, and the nuclear, envelope re forms. cleavage furrows separate the 2 cells into 4 cells
What are the differences between mitosis and meiosis
Mitosis produces two diploid daughter cells that are genetically identical
Meiosis produces four haploid daughter cells
What is a a centrosome, centriole, centromere
Centrosome- Pairs of centrioles
centriole- organizing microtubles
centromere_ where the two chromatid strands attach
what is a zygote
two haploid gametes unite
What is the normal number of chromosomes called (2 sets)
Euploid
What is polyploid
3 or more sets of chromosomes
What is aneuploidy
Abnormal number of a particular chromosome
What is Nondisjunction
Chromosomes do not sort properly during cell division and can produce aneuploid gametes during meiosis
What is Mendels 1st important idea
traits are dominant and recessive
What is Mendels 2nd idea
A gene has two variant forms or alleles
What was menders 3rd idea
two copies of a gene segregate from each other during the transmission from parent to offspring
What is a genotype
The genetic composition of an individual
What is a Phenotype
Physical or behavioural characteristics that are the result of gene expression
What is the Law of Assortment
Alleles of different genes assort independently of each other during gamete formation
In humans which chromosome is larger and carries more
the X chromosome
What is simple mendelian Inheritance
Alleles are dominant and recessive
What is Pleiotropy
A mutation in a single gene can have multiple effects on an individuals phenotype
What is incomplete dominance
Heterozygote shows intermediate phenotype, where neither allele is dominant
what is Codominance
Multiple alleles
What plays a vital role on a phenotype
the environment
What is Gene interaction
A single trait is controlled by two or more genes, each of which has two or more alleles
What are the two types of traits
Discrete and quaantative
What is a discrete trait
Clearly defined phenotype variants
What is a quantitive traits
Majority of traits
what is “probability” in genetics
The change that an event will have a particular
How do you calculate the probability
of times an event occurs/ Total number of possible outcomes
What is DNA methylation
Methyl marks added to certain DNA bases repress gene activity. it silences gene expression
What is Histone modifications
A combination of different molecules can attach to the “tails” of proteins called histones
What is epigenetic 1
genomic imprinting- Offspring express either mom or dads copy of the gene but not both
e.g insulin growth factor
What is epigenetics 2
X-Chromosome inactivation- in embryonic development, one X chromosome is randomly inactivated in each cell
What is epigenetic 3
Effects of the environment– agouti mice
BPA- disrupted methylation patterns
What is mendelian inheritance
Genes are passed unaltered from cell to cell and across generation. The genes obey menders laws of segregation. For crosses involving two or more genes.
What is Non mendelian inheritance
Epigenetic- Genes passed to offspring are altered not as a change in gene sequence but as a change in gene expression
What are two mechanisms for genomic imprinting
DNA methylation, histone modifications
What is linkage
When two genes that are close together on a chromosome are transmitted as a unit
What is a linkage group
Genes that usually stay together during meiosis
What is genetic mapping
The study of the arrangement of genes in a species genome
