Unit 6 Study Guide Flashcards
What does the word gen in genetic refer to?
Beginning
What’s a trait?
A genetically determined characteristic
Give the three subfields of genetics
- classical genetics
- molecular genetics
- population genetics
Define “animal husbandry”
Selective breeding
Who discovered the probabilistic nature of inheritance?
Gregor Mendel
What phase are cells most commonly in
Interphase
What happens during G1 phase and s phase and G2 phase?
G1 phase- “ growth” this is where the cell grows up after being made
S Phase- “synthesis” this is where the cell replicates its DNA
G2 phase- “growth” this is when the cell gets ready to split.
What is mitosis?
A cell creates more cells by the process of mitosis.
What are the four stages of mitosis?
Prophase- this is when the chromosomes condense into their familiar x shapes
Metaphase- this is when the chromosomes line up in the middle of the cell before splitting
Anaphase- this is when the chromosomes are split and in transit across the cell the opposite ends
Telophase- this is when the chromosomes are totally split and in position
What is neat about stem cells?
These cells are able to make several types of cells.
What is the G naught phase?
A phase when some cells once made do not ever split again.
Meiosis is the process of making cells called__________
“gametes”
What is a gamete
The cells which are shared during sex, sperm and egg
What process results in creation of gametes?
Meiosis
What is fertilization
The moment when the sperm and the egg meet.
What is a zygote? What is an embryo?
Embryo- two gametes together create an embryo
Zygote- The embryo becomes a zygote in this first stage
What is a blastocyst?
A ball of cells that forms early in a pregnancy
What is a fetus?
An unborn baby that develops from an embryo (after a blastocyst (
What is a gene
Region of DNA that tells the body how to make a protein
What’s an allele?
A version of a gene, it’s one of several possible forms a specific Gene can take
Example: having different colored eyes wear blue eye allele and brown eye allele, are the variations of the same gene that’s besides eye color
Give the three principles of inheritance discovered by Gregor Mendel
-Unit factors
-Dominance/recessive
-Segregation
Distinguish between genotype and phenotype
Genotype- genes behind the scenes ex. Tt
Phenotype- what you can see
Ex. Blue eyes brown hair
What is genetic segregation?
When a cell from a parent divides to create gametes, it randomly separates its pair of genes, so each gamete only gets one copy of each gene ensuring a mix of traits
Name three exceptions to Mendel’s principles
- Codominance- when both genes show up
- incomplete dominance -(neither allele is fully dominant)
- multiple alleles - when more than two alleles exist for a gene in a population
What’s an autosomal Chromosome?
Any of the first 22 chromosomes that are blueprints for almost your entire body
Xx versus XY chromosomes
Xx - female
Xy - male
What are some chromosomal abnormalities of the sex chromosomes
X- Turner syndrome
XXY- Klinefelter syndrome
XYY- Jakob syndrome
If any chromosomes are missing, the result is death. If almost any of these is tripled, the result is death. There are three abnormalities where life lasts past birth:
Trisomy 21- down syndrome
Trisomy 18- Edwards syndrome
Trisomy 13 - Patau Syndrome
What does DNA stand for and what are its three parts?
Deoxybonucleic acid
-Deoxyribose
- phosphate groups
- nitrogenous bases
What are the four nitrogenous bases of DNA?
Adenine
Cytosine
Guanine
Thymine
Dna replication
- Helicase splits the helix.
- Gyrase let’s helix spin to relieve tension
- Primase tells DNA polymerase where to start copying.
- Polymerase makes polymer of DNA on each strand, replicating it.
- Ligase binds the loose ends together.
- Polymerase goes back and checks for errors and mutations.
Transcription
- Transcription Factor proteins bind to promoter regions of DNA
- Rna polymerase reads and copies mRNA based off DNA
- Enzymes edit the mRNA. The MRNA then leaves the nucleus and finds a ribosome.
Which organelle is the site of translation?
Ribosome
Translation
- The ribosome moves left to right reading the mRNA.
- As the mRNAs codons are expressed, tRNAs will connect if their anti codons fit.
- Amino acids connect in a polypeptide chain in the order given by mRNA.
- Once the amino acids are attached, the tRNA drifts away.
- The polypeptide chain will fold up according to its amino acids chemistry.
- Empty trnas and free amino acids are properly combined together by a family of enzymes for future translation.
Define evolution
Genes will change in a population over time
How do genes change in populations? Name all 5 ways
- Non-Random mating
-Mutations (only one of these that adds not deletes information) - migration
-Drift (random events can kill off parts of a population) - selection (when genes do not evenly reproduce)
