Chapter 14 Flashcards
What are the three types of gross(big) mutations
1 change in total number of chromosomes
2 change in part of a chromosomes
3 change in arrangement of chromosomes
Two names of the changes in total number of chromosomes due to non disjunction in meiosis
Monosmy- one chromosome missing
Trisomy- one extra chromosome
Two names for change in part of a chromosome
Duplication- part of chromosome is duplicated but there’s still 46 in total (chromosome longer)
Deletion- part of chromosome is missing but there’s still 46 (chromosome shorter)
Name of Change in arrangement of chromosomes
Translation- when part of one chromosome joins another chromosome
What does (47, +21) mean
47 chromosomes in total
An extra chromosome 21
What kind of genetic material is not available from karyotype analysis
Point mutations(small mutation) When a base is missing/ single base change
What kind of information that karyotype provides about an individual
Displays if there is any types of gross mutation which cause defects- total number of chromosome
- sex determination
Define karyotype
Chromosomes present in a cell arranged in an organised manner
Define autosomal
Non sex determining Genes eg eye colour
In humans and Birds which are homogametic and heterogametic
Homogametic- females (XX)
Heterogametic- males (XY)
Birds are opposite
Female (ZW)
Male (ZZ)
Define codiminance and incomplete dominance
Co-dominance - the two phenotype share shown eg black and white spots
Incomplete dominance- blend between phenotype eg red and white makes pink
What does the circle and square stand for in pedigrees
Circle - female
Square - males
What is Environmental Sex determination and example
The sex of offspring depends on the incubation temp of the eggs
Eg happens in reptiles(turtles)
What does phenotype and environment=phenotype mean? And example
The environment can influence how genes are expressed eg environment factors include diet, temperature
Siamese cats are sensitive to temperature and in low temperatures enzymes convert the extremities of the cat(nose ears paws) to the dark colour
What is FISH
A type of fluorescent staining used to identify specific chromosomes and makes it easier to find their pair
Define homologous and nonhomologous
Homologous- the members of each matching pair of chromosomes eg the two number 5 chromosomes. They have the same length and gene loci
Nonhomologous- nonmatching chromosomes eg number 5 chromosome and number 14 chromosome
What is the general trend of genes on a chromosome
The smaller the length the less amount of genes HOWEVER there are a few exemptions for unknown reasons
What does Klinefelter syndrome show
(XX Y) extra whole chromosome
What does a female with Turner syndrome
(X0) only in females missing X chromosome
Down syndrome
Extra chromosome 21 (+21)
Limitations of data obtained from the human genome project
Social stigma/ discrimination
Who owns this information(argument)
Other then the nucleus, name two other locations DNA might be found in plant/animal cell
Mitrocondria- DNA that codes for proteins needed in cellular respiration
Chloroplasts- DNA that codes for proteins needed in photosynthesis
Where is DNA found in prokaryotes
Circular DNA which is free floating in the cytosol
How is DNA packaged into chromosomes
The negative phosphate groups of DNA is attracted to the positive histone proteins. DNA winds around the hinstones to form nucleosomes. Nucleosomes super coil to form chromosomes
Define epigenetics
Literally means above genetics. Factors other than DNA sequence, such as hinstones and methylation modification that effect expressions of genes
What are the two factors of epigenetics and explain them
Methyl group- off switches that turn off gene expressions when bound to DNA
Hinstones- loosely bound DNA=expressed more frequently
-tightly bound DNA= expressed less frequently
What is polygenes and example and formula
Multiple genes contribute to a factor eg skin colour ++ ++ means darkest colour – – lightest
Formula =2n+1
Define monogenic
Refers to traits that are under control of single genes with two alleles
Define polygenetic inheritance
Trait affected by many genes eg weight, height, skin colour (found on more then one chromosome)
How to tell if a pedigree is X linked dominant or recessive OR Y linked
Count numbers of boys and girls
More females = dominant X linked
More males = recessive X linked
Only males = Y linked
What kind of disease in Huntingtons disease
Autosomal dominant
What type of disease is cystic fibrosis
Autosomal recessive
