3C

Question 1

autosomal

Answer 1

• 2 or more genes do not independent assort during meiosis, genes are linked + stay together in the original parental combo
• linked genes passed on to offspring

Question 2

sex linkage

Answer 2

• genes on chromosome 23
• male have 1
• female have 2

Question 3

polygenic inheritance

Answer 3

charecterisitc controlled by several genes
charecterisitics show continous variation (height, mass, skin colour)

Question 4

continous variation

Answer 4

phenotypes do not fall into categories + show range in values + affected by environmental factors
(mass / height)

Question 5

operon

Answer 5

units consisting of linked genes thought to regulate other genes responsible for protein synthesis

Question 6

discontinous variation

Answer 6

phenotypic features which are either present / not

Question 7

transcription factors

Answer 7

• protein that controls transcription of genes by binding to specific regions of DNA
• TF increase ROT > actiuators
• TF decrease ROT > repressors

Question 8

splicing

Answer 8

• pp made during protein synthesis are transcripted / translated
• during transcription both introns + exons are transcribed > pre mRNA
• the non coding introns are removed
• coding (exons) joined together
• happen after transcription occurred

Question 9

alternative splicing

Answer 9

• exons spliced in many ways produce different mRNA molecules
• pp translated from alternatively spliced mRNA differ in amino acid sequence

Question 10

Epigenetic modification

Answer 10

• changes in organisim caused by modification of gene expression rather than change in genetic code
• switching on / off gene w/o changing the genetic code
• DNA wrapped around proteins called histones > form chromatin
  1. Methylation of DNA
  2. Histone modification via accetylation
• if DNA wound more tightly > gene switched off as promoter region is hidden

Question 11

DNA methylation

Answer 11

• methyl grp added to DNA
• to a cytosine base
• suppreses transc. of affected gene by inhibiting the binding of TF + enxymes needed for transc.
• turns off gene (repressed / inactivated)

Question 12

DNA accetylation

Answer 12

• accetly grp added to lysine AA on histone protein
• helps DNA wrap tightly
• during accetylation lysine remove positive ion and breaks bond
• DNA less tightly wrapped > gene is on (activated)
• removal of accetylation (deaccetylation) returns lysine + state, makes bond, gene is turned off

Question 13

mutation
epigentic

Answer 13

• affect genetic code altering base sequence
• only affect way the code is read

Question 14

toti
pluri
multi

Answer 14

• totipotent: form any cell
• pluripotent: form most cells
• multipotent: limited range

zygote (totipotent) - 1 cell
morula (totipotent) - 10-30 cells
blastocyst (pluripotent) - few cells in hollow structure
adult stem cell (multipotent)