Week 3 study notes Flashcards
pros and cons of sexual reproduction?
pros: increased genetic variability decreased genetic disorders
cons: time and energy
low
pros and cons asexual reproduction?
cons: limited diversity
difficult to adapt
pros: only one parent
more time efficiency
what is fertilizations and what types of cells are required for fertilizations to occur?
The joining of two haploid gametes (egg and sperm) restoring the diploid condition. Haploid gametes are produced from diploid germ cells
Phases of Meiosis l
what order and what occurs during each phase.
Prophase I : “before” homologous chromosomes pair up, crossing over occurs
Prometaphase I : attachment of spindle fibers microtubules to kinetochore protein at centromere, homologous chromosomes are attached to opposite poles
Metaphase I : homologous chromosomes arrange in center of cell
Anaphase I : spindle fibers pull the linked chromosomes apart, sister chromatids remain bound at the centromere
telophase I : separated chromosomes arrive at the opposite poles
Cytokinesis : separated into two daughter cells
Phases of Meiosis ll what order and occurs during each during phase
Meiosis ll : connected sister chromatids remaining in the cells will split to form four haploids cells.
Prophase ll : chromosomes reconvenes, forming new spindles
Prometaphase II : spindles are fully formed, nuclear envelopes are completely broken down, sister chromatids form an individual kinetochore and attaches to microtubules from opposite poles
Metaphase ll : sister chromatids are aligned in the center of the cell
Anaphase ll : sister chromatids are pulled apart by spindle fibers and move towards opposite poles
telophase ll : chromosomes arrive at opposite poles and begin to decondense, nuclear envelopes form around them
Cytokinesis : separating the newly formed, unique, haploid cells
Know how crossing over and random, independent assortment lead to 4 gametes that each unique
Variety — during meiosis produce gametes with unique combinations of DNA, which results in a unique combination of genes
Compare/ contrast mitosis and meiosis
Mitosis : single nuclear division resulting two nuclei.
new cell is genetically identical to origin, contains same number of chromosomes
cells produced by mitosis function in body for growth, replacing damaged cells.
Meiosis : two nuclear divisions that results into four nuclei
new cells are never genetically identical, only one chromosome set, half of original cell
Meiosis I very different from the events of mitosis, crossover chromosomes line up as tetrads
Be able to explain case study of fatherless snake
During meiosis II did not split occur which in result a diploid egg, The diploid egg contained 2 copies of Z chromosomes
What is nondisjunction? When can it occur?
Non disjunctions when pairs of homologous chromosomes or sister chromatids fair to separate during meiosis
- Can occur during meiosis I or Meiosis II
What does Monosomy and Trisomy mean? identify them on a karyogram
Monosomy = loss of one chromosomes
Trisomy = gain of an extra chromosomes
discuss different human trisomies covered in class today
Trisomy 18 - Edwards Syndrome
Trisomy 13 - Patau Syndrome
Trisomy X - Triple X syndrome
What is biotechnology? How has it improved human lives
Artificial methods to modify the genetic material of living organisms or cells to produce new compounds or functions
Finding cures to diseases
improving crops
Insulin
What is genomics?
What is genetic engineering and gene therapy? what is the goal?
Gene therapy is a specific type of genetic engineering that may be able to cure genetic diseases someday
Gene editing and predicting disease rick at the individual level are two applications of genomics and what each does
Predicting Disease Risk at the Individual level – Screening healthy people for likelihood of developing illness/disease in the future
Gene Editing - Technology allows for more precise and direct alteration of DNA – Used to edit DNA of plants, animal, and humans, overcoming illness
example cancer cell removed
