Unit 3 Part 4 Flashcards
D3.2 Inheritance
What is diploid?
Used to describe a nucleus that has chromosomes organized into pairs of homologous chromosomes
What is a heterozygote?
An organism that possesses one dominant allele and one recessive allele (ex. Tt)
What is a monohybrid cross?
When parents have different alleles and it shows the results for only one trait
What does homozygous dominant mean?
Both alleles are dominant
What does homozygous recessive mean?
Both alleles are recessive
What is the first filial generation?
First generation produced by a cross
What is self pollination?
When a plant’s polen lands on flowers it has produced itself, this can result in self-fertilization
What can farmers do when they want plants with the same characteristics as previous generations?
They can use self pollination techniques
What can farmers do when they want plants with new characteristics not seen before?
They can use cross pollination techniques
What is a gene?
A DNA sequence that codes for a protein that will give an organism a specific trait
What is a genotype?
The symbolic representation of the pair of alleles possessed by an organism (ex. BB, Bb, bb)
What is homozygous?
Having two identical alleles of a gene
What is heterozygous?
Having two different alleles of a gene
What is a carrier?
An individual who has a recessive allele of a gene that dies not have an effect on phenotype
What is a dominant allele?
Allele that has the same effect on the phenotype whether it is paired w/same allele or not
- Always expressed in phenotype
What is a recessive allele?
Allele that has an effect on the phenotype only when no dom allele is present to mask it
What are codominant alleles?
Pairs of alleles that both effect phenotype when present in a heterozygote
What is phenotypic plasticity?
An organism’s ability to express its phenotype differently depending on the environment
Phenological?
Cyclical events like seasonal food availability
What type of changes can phenotypic plasticity generate?
Can generate changes in physiology, morphology, behavior, or phenology
How can two healthy parents create a child w/ a genetic disease?
Disease is caused by recessive alleles so both parents must be carriers of the version of gene that causes the disease
How is phenylketonuria (PKU) caused?
Caused by mutations in the autosomal PAH gene that results in low levels of enzyme phenylalanine hydroxylase
What are autosomal recessive diseases?
Diseases that are caused by recessive alleles and their locus gene is found on one of 1st 22 pairs of chromosomes but on sex chromosomes x or y
When does single - nucleotide polymorphism occur
When a nucleotide of the genetic code like T is not found where expected to but replaced by C
I^A allele
Allele for producing proteins called type A antigens = type A blood
I^B allele
Allele for producing proteins called type B antigens = type B blood
i allele
Recessive allele that produces neither A or B antigens = type O blood
I^AI^A or I^Ai phenotypes
Gives phenotype of type A blood
I^BI^B or I^Bi phenotypes
Gives phenotype of type B blood
I^AI^B phenotypes
Gives phenotype of type AB blood
ii phenotype
Gives phenotype of type O blood
Amount of genes in x and y chromosomes
x = around 800
y = around 70
What is a sex - linked trait?
Any genetic trait that has a gene locs on X or Y chromosome
Process of clotting
When a small cut or scrape on skin stops bleeding after a few minutes and eventually forms a scab
Where are alleles for haemophilia found?
Only on X chromosomes
- Only females can be carriers
What is pedigree?
Record of an organism’s ancestry
What is polygenic inheritance?
Involves two or more genes influencing the expression of one trait
What is continues variation?
When an array of possible phenotypes can be produced
Discontinues variation in graphs?
- In distinct categories which have no transition between them
- Order does not matter
- Best plotted as bar charts
- Can determine a mode but not a mean
Continues variation in charts?
- Not in distinct categories
- Order matters
- Smooth transition from one value to next w/ no abrupt jumps
- Best plotted as histograms or curve
- Can determine a mean
Inductive reasoning?
When a conclusion or theory is worked by looking at samples of evidence of a phenomenon
Deductive reasoning?
When we apply well established knowledge about a phenomenon to reach a conclusion or theory to explain what’s happening
What is discontinues variation?
When variation is not continuous
How can quartiles be determined?
By entering the data points in a graphing calculator or spreadsheet program
What is Quartile 1?
The middle value between the median and the lowest value in the data set, otherwise expressed as 25th percentile
What is Quartile 2?
Median or the data point at the 50th percentile
What is Quartile 3?
Middle number between the median and the highest value in the data set, 75th percentile
What does the interquartile range do?
Measures the spread of the data and is defined as the difference between 75th and 25th percentiles
