FAQ’s-Genetics

DNA Replication

• DNA is “unwound”• Bases match up with complementary base pair

(A-T, G-C)• Semi Conservative

Transcription

• DNAmRNA using base pair rules– On RNA, have Uracil instead of Thymine

Translation

• mRNA protein• Steps:

1. mRNA finds Ribosome (remember ribosomes make proteins???)

2. tRNA comes in with amino acid (building block of protein), matches up with mRNA

3. Ribosome lines amino acids together into a chain

Genetic code is UNIVERSAL

• Replication (for the most part), transcription and translation HAPPENS IN ALL LIVING THINGS THE SAME WAY

• That’s WHY we can take a human gene, but it in a bacteria and it STILL WORKS

DNAmRNA

A. ReplicationB. TranscriptionC. Translation

mRNAprotein

A. ReplicationB. TranscriptionC. Translation

DNADNA

A. ReplicationB. TranscriptionC. Translation

In DNA replication, why is it SO IMPORTANT that A’s and T’s match up, and G’s and C’s match up?

All organisms have the same genetic code and make proteins the same way

A. TrueB. False

Dominant vs. Recessive alleles

• Dominant allele-will always show up• Recessive allele-will only show up if individual

is homozygous recessive

Codominance

• When BOTH alleles are dominant, so they BOTH show up

• Ex. Roan cows

Sex Linked

• Males: XY, females: XX• Sex-linked traits-always found on X

chromosome• Males more likely to have these traits• Only females can be carriers(XAXa)

Punnett Square!!!

• Cross a heterozygous black lab (Bb) with a homozygous recessive yellow lab (bb) and give phenotypic/genotypic %’s

Mutations=change in number/order of bases in DNA

• Deletion-base gets deleted while DNA is replication

• Point mutation-happens at ONE base in DNA• Can be:– Silent-don’t do anything– Nonsense-change “stop” signal

• End too early• Never end

– Frame shift-change ENTIRE protein• THE FAT CAT ATE THE RAT

Which would you rather have? Silent, nonsense or frame shift and WHY, explain what each is in your answer

• DNA-contains our genetic information• Genes-segments of DNA that code for a

trait/protein• Alleles-different forms of genes (blue eye

allele etc)• Chromosomes-X-shaped structures consisting

of tightly wound DNA segments

Fill in the blanks:

• ___________ have many different forms called _____________. ______________ are made up of tightly wound __________.

• Word bank:– Chromosomes, DNA, alleles, genes