genetics (easy) for practice

What are the stages of mitosis?

Prophase, Metaphase, Anaphase, Telophase

What happens in mitosis?

one cell divides into two identical cells

What happens in meiosis?

one cell divides into four haploid cells

Main difference between mitosis and meiosis?

Mitosis = identical cells; meiosis = genetically different cells

Sources of genetic variation in meiosis?

crossing over and independent assortment

What happens during interphase?

cell grows and DNA replicates

Which is faster: prophase or anaphase?

anaphase

What separates in Anaphase I?

the homologous chromosomes

What separates in Anaphase II?

sister chromatids

What is nondisjunction?

failure of chromosomes to separate

What can nondisjunction cause?

abnormal chromosome numbers

2N = 16 means what?

the diploid cell has 16 chromosomes

How many chromosomes in a haploid set if 2N =16?

8

What does G2 mean?

DNA has replicated

How many DNA molecules per chromosome in G2?

2

Mendel’s First Law?

Law of Segregation

Mendel’s Second Law?

Law of Independent Assortment

What is segregation?

when alleles separate during gamete formation

What is independent assortment?

genes assort independently into gametes

Monohybrid cross ratio?

3:1

Dihybrid cross ratio?

9:3:3:1

Why do linked genes break Mendel’s law?

they are inherited together

What is crossing over?

exchange of DNA between homologous chromosomes

What is recombination frequency?

% of recombinant offspring

1% recombination equals what?

1 map unit

What are multiple alleles?

more than two allele forms exist

Example of multiple alleles?

ABO blood group

Why is incomplete dominance different?

heterozygote shows blended phenotype

Incomplete dominance F2 ratio?

1:2:1

Why are X-linked traits more common in males?

males only have one X chromosome

What is a testcross?

cross with a homozygous recessive

What is Alu?

short repetitive DNA sequence

What is the PV92 locus?

site where Alu insertion may occur

Where does Alu insert?

an intron

What is PCR?

a DNA amplification technique

Purpose of PCR?

make many copies of DNA

What is gel electrophoresis?

separates DNA by size

Why run a gel?

to see DNA fragment sizes

Smaller DNA fragments move how?

farther through the gel

Where did DNA come from in lab?

cheek cells

Purpose of Chelex heat step?

break open cells and protect DNA

What is transcription?

Making RNA from DNA

What is translation?

making protein from mRNA

Role of promoter?

starting point for transcription

Role of RNA polymerase?

Builds RNA strand

Role of mRNA?

carries genetic code

Role of tRNA?

brings amino acids

Role of ribosomes?

Site of protein synthesis

What is a codon?

3-base sequence on mRNA

What is translocation?

Ribosome moves to next codon

Why does amino acid sequence matter?

Determines protein shape

Why is protein shape important?

shape determines function

What are disulfide bonds?

strong bonds stabilizing proteins

What does a codon table do?

matches codons to amino acids