Chapter 1 &2 Flashcards
What is Classical genetics
All genetics before the discovery of DNA
What does Medelian genetics deal with?
DNA and chromosomes
What is population genetics?
genes inheritated within a population
What is molecular genetics?
deals with DNA, RNA, and proteins
What are model genetic organisms
species chosen for research
What is an example of model genetic species?
fruit flies
What is the difference between domesticated and cultivated plants?
domesticated:
- undergo the shattering process (cant shed seeds)
- humans control the population
- can’t survive on their own
Cultivated:
- ability to shed seeds
- survive on their own
What are the 7 critical ideas of inheritance?
- pagenesis
- inheritance of acquired characteristics (Lamarck)
- blending inheritance
- particulate inheritance
- cell theory
- germ-plasma theory
- Medelian inheritance
Which of the 7 critical ideas of inheritance of correct?
- particulate inheritance
- cell theory
- germ-plasma theory
- mendelian inheritance
What took place in 1859?
Darwin: “On the Origin of Species.” embraced pangenesis
What took place in 1900?
rediscovery of Mendel against a background of cytogenetics
What took place in 1930?
population genetics
- populations evolve, not individuals
What took place in 1953?
Watson and Crick discover of DNA structure
What took place in 1973?
first true recombinant DNA technology
What took place in 1977?
DNA sequencing: Sanger method
What took place in 1983?
polymerase chain reaction (PCR)
- ability to reduce DNA in a lab
What took place in 2000
draft human genomic sequence
Are viruses only RNA stranded?
no, DNA and RNA
prokaryotes have circular or linear chromosomes?
circular
prokaryotes have how many:
- circular chromosomes?
- origin of replication?
1
Which cell division process involves the division of somatic cells?
mitosis
Which cell division processes involve the division of gametes?
meiosis
Which cell division prosess involves the division of the cells
cytokinesis
What happens if mitosis or cytokinesis occur without the other?
a cell with contain more than one nuclei
What cell division process do prokaryotes undergo?
binary fission
Describe an eukaryotic chromosome
- double, antiparellel DNA molecules bound to histone proteins
- histone proteins coil the DNA
Where are these located on a chromatid?
- centromere?
- telomere
- the center
- at both ends
When two chromatids are joined what are they called?
At what location are they joined at?
- sister chromatids
- the centromere
The joined centromeres of sister chromatids becomes a site for what?
What is it attached to?
- kinetochore
- spindle apparatus
How are chromosomes classified?
What are the types of classifications?
- centromere position
- telocentric (little-no top legs)
- acrocentric (small top legs)
- submetacentric (medium top legs)
- metacentric (long top legs)
What stages take place during interphase?
- G1 (gap)
- S (synthesis)
- G2 (gap)
Interphase:
What takes place during G1?
- cell growth
Interphase:
What takes place during S phase?
DNA replication
Interphase:
What takes place during the G2 phase?
further growth of the cell
What are the 3 checkpoints of the Mitosis cycle?
What are they checking?
- G1/S
- confirm everything is properly functioning
- G2/M
- confirming the DNA was fully replicated
- M
- confirm that all chromosomes are attached to the spindles (protruding from the spindle apparatus) and correctly positions in the middle of the cell
Interphase:
What is the G0 phase?
Where does it take place
- may interrupt G1 before proceeding to the G1/S checkpoint if chromosomes didnt grow properly
What takes place during prophase?
- condensing of chromosomes
- spindles begin to form
- microtubles are reconfigured
- cytoskeleton is dissolved
Microtubles are made of what type of protein?
tubulin
What takes place during prometaphase?
- nuclear envelope disintegrates
- chromosomes attatch to two microtubles
- chromosomes pulled to equater
During Mitosis, the cell equator is also called what?
metaphase plate
What takes place during metaphase?
- all chromosomes reach metaphase plate
- M checkpoint
Aligned along the metaphase plate, why do the chromosomes twitch?
both poles of the cell pull the chromosomes in opposite direction
- spindles are attached to both side of the sister chromatid’s centromere, and pulled in opposite directions, causing tension
What takes place during anaphase?
- sister chromatids seperate
- both chromatids are pulled by spindles to seperate poles
What is separase’s function?
cuts the fused centromere of the sister chromatids into two separate centromeres
What occurs during telophase?
- chromosomes reach the poles and stop moving
- the reverse process of prophase and prometaphase begins
- nuclear envelope re-forms
- spindle apparatus dissolves
- chromosome de-condense
What occurs during cytokinesis?
- Animalia?
- Plantae?
- Fungi?
Animalia
- cleavage furrow (pinch of cells)
Plantae
- cellulose based cell wall
- cell plate forms (from inside out)
Fungi
- chitin based cell wall
- cell plate forms (from outside in)
If biological variation doesn’t produce new alleles, what does?
mutations
Meiosis:
What phases occur during prophase 1?
- leptotene
- zygotene
- pachytene
- diplotene
- diakinesis
Meiosis : Prophase 1
What occurs during leptotene?
chromosomes condense
Meiosis : Prophase 1
What occurs during zygotene?
- synapsis pairs homologous chromosomes
- crossing over begins
What is the structure called when crossing over occurs between homologous chromosomes?
What are they also called?
- tetrads
- bivalents
Meiosis : Prophase 1
What occurs during pachytene?
- crossing over continues
- synaptonemal complex forms between homologous chromosomes
Meiosis : Prophase 1
What occurs during diplotene?
- completion of crossing over
- synaptonemal complex is lost
- chromatids are looser
Meiosis : Prophase 1: diplotene
What holds homologous chromosomes together?
I is requires in every case?
- chiasmata
- no
Meiosis : Prophase 1
What occurs during diakinesis?
- chiasmata slips to the ends of chromatids
- chromosomes slowly condense
- spindle apparatus forms
- nuclear envelope disappears
What is the result of meiosis?
four haploid nucei
What occurs during crossing over?
When does it occur?
- always during prophase 1
- DNA breakage and repair joins chromatids from homologous chromosomes
What is Independent assortment?
random separation of homologous chromosomes
What attaches sister chromatids as they are formed during S phase?
cohesion
Mitosis:
What breaks all of the cohesion at once at the beginning of anaphase?
separase
After the cohesion arm is cut of during anaphase 1, the molecules at the centromere are protected by what type of protein?
shugoshin
Plants and Animals:
Describe the cell division of sperm
- one diploid cell makes four haploid cells through meiosis
- cytokinesis is equal both times, producing four sperm cells
Plants and Animals:
Describe the cell division of ovum
- one diploid cell undergoes unequal cytokinesis stages
- all cytoplasm goes to one product and the remaining 3/4th become small cells and die off
Plants and Animals:
The cell division of ovum is called?
oogamy
Cell division of ovum:
The remaining 3/4th of chromatids result in small cells called what?
polar bodies
How do the cellular division of ovum and sperm differ between plant and animals?
Animals
- oogamy process is homologous
Plants
- oogamy process is analogous
- haploid cells undergo mitosis before fertilization
How do fungi fertilization differ from plants and animals?
they don’t contain specialized gamete (only +/-)
