Bio Class 6

Question 1

When is it diploid vs haploid?

Answer 1

When homologous chromosome is present it is diploid, when it is not it is haploid

Question 2

Prophase I

Answer 2

• DNA condenses, mitotic spindle forming, nuclear membrane breaks down
• synapsis (pair homologous chromosomes)
• crossing over - exchange of DNA

Question 3

Tetrad

Answer 3

Pair of homologous chromosomes (4 chromosomes together

Question 4

Metaphase I

Answer 4

Tetrads align at cell center

Question 5

Anaphase I

Answer 5

Separate homologous chromosomes
Cytokinesis begins
Ring of actin forms (cleavage burrow)

Question 6

Telophase I

Answer 6

• Reverse of prophase I
• Finish cytokinesis
  At the end of meiosis I you have 2 haploid cells
  Moves to meiosis II

Question 7

Prophase II

Answer 7

similar to prophase I

Question 8

Metaphase II

Answer 8

similar to metaphase I

Question 9

Anaphase II

Answer 9

Separation of sister chromatids

Question 10

Telophase II

Answer 10

similar to telophase I

Question 11

End result of meiosis I & II

Answer 11

You have 4 cells, each with 23 chromosomes

All chromosomes are different from each other & parent ell

Question 12

Meiosis is also called…

Answer 12

Reductive division

Question 13

Nondysjunction

Answer 13

Failure to divide DNA during meiosis
Anaphase I failure: all 4 gametes are abnormal
Anaphase II failure: 2 will be normal, 2 will be abnormal

Question 14

Gene

Answer 14

Piece of DNA that codes for product

- includes regulatory regions (eg. promoter, untranslated region)

Question 15

Trait

Answer 15

• known as phenotype
• physical characteristics resulting from genes
  a. Polymorphic
  b. polygenic

Question 16

Allele

Answer 16

Version of gene

Superscript differs in capital/lowercase

Question 17

Polymorphic

Answer 17

many forms due to the expression of many alleles

Question 18

Polygenic

Answer 18

many forms due to expression of many genes

Question 19

Non-classical dominance

Answer 19

1. Incomplete dominance - heterozygote is blended phenotype; genotype will have 2 different uppercase letters
2. Codominance - alleles are expressed independently of each other at same time
3. Epistasis - dominance between genes (expression of one gene regulates expression of another gene)

Question 20

Classical dominance

Answer 20

1 allele is dominant, 1 is recessive

Question 21

Human ABO Blood group gene

Answer 21

On surface of RBC, you have an area that codes for protein on the surface
3 versions of alleles: Ia (codes for A protein), Ib (codes for B protein) & i (codes for no protein

Question 22

Universal donor? Universal receipent?

Answer 22

Donor is: O- because no proteins to trigger reaction in recipient

Acceptor is: AB+ because has A/B/Rh factor

Question 23

Blood typing Process

Answer 23

1. Rh factor: determined through classical dominance (R codes for Rh protein) r (doesn’t)
   RR or Rr = Rh+ / rr = Rh-
2. Complete blood type is combo of ABO and Rh genotype
3. Transfusion Reactions
   - Immune system designed to recognize foreign proteins

Question 24

Mendel’s Laws

Answer 24

1. Law of Segregation

2. Law of Independent Assortment

Question 25

Law of segregation

Answer 25

Alleles are separated during gamete formation (anaphase I + II)

Question 26

Law of independent assortment

Answer 26

How one pair of alleles separates is independent of another pairs separation (depends on how chromosomes meet in metaphase)

Exception: If linked, it will not be independent

Question 27

Mendel’s Law

Answer 27

1. Law of segregation - Alleles are separated during gamete formation
2. Law of Independent Assortment - One pair of alleles separation is independent of another pairs separation

Question 28

4 basic single gene crosses

Answer 28

1. Heterozygote x Heterozygote
   Phenotype: 25% dominant, 50% hetero, 25% recessive
   Genotype: 75% dominant, 25% recessive
2. Homozygote x same Homozygote
   Phenotype: 100% parental
   Genotype: 100% parental
3. Heterozygote x Homozygote (recessive/dominant)
   Phenotype: 50% dominant, 50% homozygote x
   Genotype: 50% heterozygote, 50% homozygote x
4. Homozygous dominant x homozygous recessive
   Phenotype: 100% dominant
   Genotype: 100% heterozygote

Question 29

Rules of probability

Answer 29

Rule of multiplication (A & B happening at same time)
Probability (A and B) = prob (A) x prob (B)

Rules of addition (probability of A OR B happening at same time

Mutually exclusive (nothing in common)
prob (A) + prob (B)

Nonmutually exclusive
prob (A) + prob (B) - (prob A x prob B)

Question 30

Linked genes

Answer 30

found close together on the same chromosome so when cross over happens it does not separate

To know if genes are linked, you have to look at F2 generation

Question 31

Unlinked ratio

Answer 31

d/d 9/ 1
d/r 3/ 1
r/d 3/ 1
r/r 1/ 1

Question 32

Recombinant frequency

Answer 32

Recombinant frequency (RF) = # of recombinants/ total # of offspring x 100%=
- unit: map units (mu)

Question 33

Hardy-weinberg principle

Answer 33

Allele frequencies do not change from generation to generation

Question 34

H-W equations

Answer 34

Phenotype frequency:
p + q = 1

Genotype frequency:
pp + 2pq + qq = 1

p= dominant allele
q = recessive allele
pq = heterozygote

Question 35

What are the 5 conditions that hold true for the H-W equations?

Answer 35

1. Mating has to be random
2. No migration (no inward or outward flow of alleles)
3. No natural selection (bc this would increase the probability of good alleles)
4. Large population (small population means it’ll be affected by small events)
5. No mutation