Exam 1 Flashcards
Transmission genetics
- very early concept (meiosis and mitosis)
- early theory of heredity transmission that states specific particles (gemmules) carry information from the body to reproductive organs which are passed to the embryo at conception
Molecular genetics
- replication
- how DNA is maintained … Zooming in
Population genetics
- look across an entire population and observe natural selection
- how population changes through time
Why are Model organisms important
- easy to grow and maintain in a lab, organisms used to study human diseases
Give an example of a model organism
- bacteria
Early theories of heredity
- domestication
- artificial fertilization (Assyrians)
- Hindu writings said they avoided spouses with undesirable traits
1) Pangenesis
2) acquired inheritance
3) preformation
4) blending
Pangenesis
- specific particles (gemmules) carry information from the body to reproductive organs which are passed to embryo at conception
- very early concept of hereditary transmission
- slide 18
Inheritance of acquired characteristics
- early theory of hereditary transmission
- Greeks proposed traits acquired in life incorporated into heredity info and passed on
Ex: an artist would pass his art skills that he acquired during life onto their offspring
Robert Hooke
- discovered the cell using a microscope
Preformationism
- early theory of hereditary transmission
- inside the egg or sperm is a tiny version of an adult (homunculus)
Blending inheritance
- early theory of hereditary transmission
- offspring are a blend of their parents
Schwann and Schleiden
- proposed the cell theory
- > stated that cells are the basic unit of all living things
- > cells arise from preexisting cells
The cell theory
- cells are the basic unit of all living things
- cells arise from preexisting cells
Charles Darwin
- theory of evolution through natural selection
- also wrote the origin of species
- > said that heredity was the fundamental unit of evolution
Origin of species
- heredity was the fundamental of evolution
Gregor Mendel
- discovered basic principles of heredity
- crossed pea plans and analyzed patterns of transmission
Walter Flemming
- first person to observe the division of chromosomes during mitosis
- discovered hereditary information was contained in the nucleus of a cell
August Weismann
- cut the tails off of 22 mice for 22 generations and the tail length of the descendants never changed .. This proved the acquired characteristic theory to be wrong
- purposed the germ plasm theory that said the cells of the reproductive system carry an already complete set of information to be passed down to the next generation
Germ plasm theory
- the cells of the reproductive system carry an already complete set of information
- slide 24
The three major groups of life
1) eubacteria- true bacteria
2) archaea
3) eukaryotes
Prokaryotic cells
- absent nucleus
- small
- one circular DNA molecule
- DNA is not complex
- absent organelles
- absent cytoskeleton
Eukaryotic cell
- has a nucleus
- larger
- multiple linear DNA
- the DNA is complex
- there are membrane bound organelles
- the cytoskeleton is present
Animal vs Plant cell DNA material
Both
- nucleus*
- nuclear envelope*
- Endoplasmic reticulum
- ribosomes
- mitochondria *
- membrane
Plant cell only
- vacuole
- chloroplast*
- cell wall
Are viruses living cells?
- no!
- they have genetic info, but can can only reproduce inside of a host cell
Prokaryotic Cell Reproduction
- binary fission
1) starts with a circular chromosome within a prokaryotic cell
2) chromosome replicates
3) membrane grows, chromosomes separate
4) cell divides, each cell is genetically identical
Eukaryotic cell reproduction
- has 2 sets of chromosomes/cells (as a result of sexual reproduction)
- one set from the mother and one set from the father (homologous pairs)
2 sets of genetic info= diploid (eukaryotic cells)
1 set of genetic info=haploid (reproductive cells)
Homologous pairs of chromosomes- humans have 23 pairs
Ploidy
- the number of sets of chromosomes in a cell, or in the cells of an organism
- each set is designated by n
- diploid or haploid
Diploid
- two sets of homologous chromosomes
- 2n
- one chromosome from mom and one from dad
- most eukaryotic cells (mammals)
- reproduced during mitosis
Haploid
- one complete set of chromosomes
- n
- a cell with half the number of chromosomes found in the nucleus
- reproductive cells (gametes or sex cells)
- produced by meiosis
Chromosome structure includes
- telomere
- centromere
- two (sister) chromatids 👭
- kinetochore
- spindle microtubules
Telomere
- cap on the end of a chromosome that protects from chromosomal rearrangement
Centromere
- in order to get through cell division
- essential for movement of chromosomes in meiosis and mitosis
- lets describe the structure based on where it is located on the chromosome
- one for every chromosome, indicates the number of chromosomes
Sister Chromatids
- Genetically identical chromatids connected at the centromere, considered one chromosome
Kinetochore
- forms around the centromere
- place where spindle fibers connect
Spindle microtubules
- fibers made up of tubular subunits and attaches to the kinetochore from the centre some to pull sister chromatids apart
The 4 major types of chromosome structure
1) metacentric
- centromere is located in the middle of the chromosome
2) submetacentric
- centromere located slights to one side of the chromosome
- has a p-arm=petite smaller end of chromosome
- has a q-arm=larger end of chromosome
3) acrocentric
- centromere is located ALMOST at the end of the chromosome
4) telocentric
- centromere is at the tip of the chromosome
Cell cycle
1) G1 Phase
2) G0 Phase
3) G1/S checkpoint
4) S Phase
5) G2 Phase
6) G2/M Phase
7) Mitosis
8) Cytokinesis
G1
- cell growth, metabolically active
G0
- no dividing stage, doesn’t enter the cell cycle
G1/S checkpoint
- checkpoint makes sure the cell is healthy and not damaged before it enters the S stage
- once you go past the checkpoint the cell is committed to dividing
S Phase
- phase in cell cycle where DNA synthesis occurs
- replicate your DNA (sister chromatids form)
G2 Phase
- phase in the cell cycle where the cell continues to grow and prepare for division
G2/M Checkpoint
- checkpoint in cell cycle in which beyond this point the cell CAN divide
Mitosis Phase
- division of genetic makeup in the nucleus
M or Spindle checkpoint
- in cell cycle the assembly checkpoint after mitosis
M=mitosis phase
Interphase
- the longest stage in the cell cycle
- DNA synthesis occurs
- phase in mitosis where DNA replication occurs
- > G1, S, G2 phases
Cytokinesis
- cytoplasm divides, the entire cell division
Mitosis Phases
- nuclear division-> nucleus divides
1) interphase
2) prophase
3) prometaphase
4) metaphase
5) anaphase
6) telophase
Prophase
- phase in mitosis where chromosomes condense
- DNA is ALREADY replicated
- can see distinct chromosomes
- spindle fibers form from centrosomes(ANIMALS)
Prometaphase
- phase in mitosis where the nuclear envelope disappears which allows microtubules to contact chromatids
- once they contact chromosomes they can move them via centromere to line them up
Metaphase
- phase in mitosis where chromosomes arrange in a single plane called the metaphase plate
- every chromosome is lined up by themselves!
Anaphase
- phase in mitosis where sister chromatids move toward opposite poles and become 2 chromosomes (2n)
- after separation chromatids become chromosomes