Unit 5 Flashcards
Diploid
a cell that has 2n
n means a set of chromosomes
Haploid
a cell that has n - like sex cells
one set of chromosomes
Homologous Pairs
2 pairs of the same chromosome
Example:
Hair color chromosome from mom
Hair color chromosome from dad
gametes
sex cells
autosomes
non-sex cells
zygote
1 haploid from mom + 1 haploid from dad
Gene
the coding for a trait
allele
One homologous pair
locus
the specific part which codes for the specific trait
Homozygous
the homologous pairs are the same
Heterozygous
the homologous pairs are different
Genotype
the code
Phenotype
what you see
What two groups are genes in?
Dominant
Recessive
The Law of Dominance
Dominant traits are dominant to recessive traits
The Law of Segregation
Only one of each parent’s homologues pairs are given to the child
The Law of Independent Assortment
Genes are sorted into gametes independently from each other
If there are two UNLINKED genes involved:
Ratio = 9:3:3:1
Linked Genes
- It is on the same chromosome and close
- Moves as a group
- Violates the law of Independent Assortment - defies ratios
What causes Linked Genes?
Being Close together - they cannot recombinant
Recombination Frequency Equation
{(number of recombinations) / (total number)} x 100%
Crossover is proportional to distance
Repeat
Map Units
a unit of measurement for spatial data in a map or scene, and a unit for measuring genetic linkage
Centimorgans
a map unit
Sex - Linked Traits
The gene is on the X chromosome and generally recessive, making males more suseptable
Incomplete Dominance
A mixed trait
Codominance
you can see two distinct traits
Polygenic Inheritance
A single gene has a small impact on a trait
Non - nuclear Inheritance
Mitochondria and Chloroplasts, which is from the mother, contain genetic material
pedigree
a genetic tree
phenotype plasticity
even though two beings may have the same genotype, the phenotype will differ due to environmental effects
gondas
sex organs
testes
Male Sex Organs
Ovaries
Female Sex Organs
Meosis
The duplication of sex cells - which happens during puberty
What is Meiosis also known as?
Gametogenesis
What are the two types of Gametogenesis
- Spermatogenesis - male
- Oogenesis - female
Oogenesis has 1 ovum and 3 polar bodies, which die
stamen
the male reproductive organ of flower
carpel
the female reproductive organ of flower
Cross Test
In order to know what the genotype is, you breed it with a homozygous recessive alleles
Gene Environment Interaction
(Genes) + (Environment) = (Behavior)
Continuous
A whole bunch of variation - not just tall and short
Complex
more than one factor determining a certain trait - they add up
Incomplete penetrence
a term used to describe when some people with a genetic mutation that causes a disease do not develop the disease
Variable expressivity
a genetic phenomenon where individuals with the same genetic condition have different signs and symptoms
aneupoly
having an abnormal number of chromosomes
what are the two types of aneupoly
- monosomy - missing homologous partner
- trisomy - an extra homologous partner
Why does weird cells occur?
Sperm cells might be defective - Meiosis did not separate right
Types of Rearrangement of Chomosomes (4)
- Duplication
- Deletion
- inversion
- translocation
what is the affect of a weird chromosome
Down Syndrome
What causes variation of species?
Only one of the homologous of the parents is given to the child - fertilization, half an allele is given to each of the four daughter cells
Product Rule
Two Independent traits SIMUTANEOUSLY
Sum Rule
Two independent traits either/or
Gametogenesis
Reproduction of sex cells
Oogenesis
gametogenesis in Females
Spermatogenesis
gametogenesis in Males
Non-Disjunction
Failure of chromosomes fully separating- causing too many or too few cells
What are Barr Body?
In a female XX, one X RANDOMLY chromosome condenses and deactivates and is handed down to a daughter cell
somatic cells
body, NONsex cells
Monohybrid Cross
ONE gene is being studied
Dihybrid Cross
TWO genes are studied - so you must make all different kinds of combinations of those two genes - both dominant and recessive
What is the ratio of two heterozygous traits crossed?
Dominant: One D One R: One R One D: Recessive
9:3:3:1
What is special about meiosis?
VARIATION
What are some factors that contribute to variation in meoisis?
- lining up randomly in prophase I
- crossing over
- chromosomes randomly assort into four daughter cells
Meiosis II is pretty much…
Mitosis
synapsis
the fusion of chromosome pairs at the start of meiosis
tetrad (bivalent)
the four sister chromatids that are held together into two parts
translocation
A genetic change in which a piece of one chromosome breaks off and attaches to another chromosome
