1. Plant GeneticsPlant Genetics
JJA Obico, Department of BiologyJJA Obico, Department of Biology
University of the Philippines Manila

2. Study of heredity and hereditary variationS udy o d y a d d a y a a o
Genes
- hereditary units
- Segments of DNA
Chromosomes
- DNA + proteins
GeneticsGeneticsGeneticsGenetics

4. A. Interphasep as
1. Gap 1 or G1 phase
2. Synthesis phase or S phase
3. G2 phase
B. M-phase (Mitosis or Meiosis)
Cell CycleCell CycleCell CycleCell Cycle

5. 1. G1
h th ll d◦ where the cell spends
most of its functional
life
◦ Performs metabolic
acitivities
2. S-phase
◦ DNA molecules are
copied or replicatedcopied or replicated
◦ from single
stranded DNA in G1
phase to double
stranded DNAstranded DNA
3. G2
◦ preparing for the
actual division events
InterphaseInterphase
(much protein
synthesis- tubulin)
InterphaseInterphase

8. MeiosisMeiosisMeiosisMeiosis

9. Asexual or Sexual Reproduction?p
1. Crossing over
2. Independent assortment of chromosomes
3. Random fertilization
SOURCES OF VARIATIONSOURCES OF VARIATIONSOURCES OF VARIATIONSOURCES OF VARIATION

10. Crossing overCrossing overCrossing overCrossing over

11. Independent assortment of chromosomesIndependent assortment of chromosomesIndependent assortment of chromosomesIndependent assortment of chromosomes

12. 2n
223 The no. of possible combination
of maternal and paternal chromosomes in
the gametes
Random fertilization of an ovumRandom fertilization of an ovum
by a spermby a spermby a spermby a sperm

16. True-breeding plantsu b d g p a s
Two varities
◦ Purple flower
◦ White flower
Hybridization
M h b idMonohybrid cross

18. Whatever the factor that caused thea a o a aus d
purple color was more powerful than
the factor for white color
Mendel said that the yellow factor
"d i t d" th f t"dominated" the green factor.

19. 1. Alternative version of genes account fora s o o g s a ou o
variations in inherited character
Mendel’s findingsMendel’s findingsMendel s findingsMendel s findings

20. 2. For each character, an organism inheritso a a a , a o ga s s
2 alleles: one from each parent
Homozygous– identical alleles
Heterozygous– different alleles

21. 3. Dominant allele – fully expressed3 o a a u y p ss d
Recessive allele – masked
Dominant- uppercase
Recessive – lowercase
P- purple; p- white

22. 4. Two alleles for each character segregateo a s o a a a s g ga
during gamete production – LAW of
SEGREGATION
AN ovum or sperm get only ONE of alleles
f ll thof all the genes

24. PUNNETT squareU squa
- A tool for predicting the results of a
genetic cross
P P
p Pp Pp
p Pp Pp
What will be the physicalWhat will be the physical
appearance?appearance?appearance?appearance?

25. Self pollinate Pp individualsS po a p d dua s
P p
P PP Pp
P Pp pp

26. Pp, PPPp, PP-- same phenotype but different genotypesame phenotype but different genotype

28. Seed shape and seed colorp
Round and wrinkled; yellow and green
RRYY x rryy
G t RY RY dGametes: RY;RY and ry;ry
F1: RrYy self pollinate
RrYy x RrYyRrYy x RrYy
Gametes (dependent assortment): RY;ry
and RY; ryy
F2?
Are they transmitted as package?
Will Y d R d d t t th ?
DihybridDihybrid crosscross
Will Y and R; and r and y stay together?
DihybridDihybrid crosscross

31. Probabilityobab y
The number of ways an event can occur
total number of possible outcomesp
ranges from 0 to 1
MendelianMendelian inheritance reflectsinheritance reflects
rules of probabilityrules of probabilityrules of probabilityrules of probability

32. Product Ruleodu u
◦ For independent events
Sum Rule
◦ Events that can occur in two or more different
ways
What is the probability of getting a heterozygoteWhat is the probability of getting a heterozygote
(Pp) in this cross?
A B
Pp x Pp
1. P= ½ ; p= ½ ¼
2 p= ½; P = ½ ¼2. p= ½; P = ½ ¼

33. 1. Incomplete dominance
NonNon mendelianmendelian inheritanceinheritanceNonNon mendelianmendelian inheritanceinheritance

34. 2. Multiple alleles- more than 2 allelesu p a s o a a s

35. 3. Polygenic inheritance

37. 4. pleiotropy- single gene controls morep o opy s g g o o s o
than one character
eg. one gene affects corolla, anther, calyx,
leaf and capsule of tobacco

38. 5. Linked genes- genes are on the same5 d g s g s a o sa
chromosome

39. 6. Cytoplasmic inheritance6 Cy op as a
- Maternal inheritance
- Extra nuclear genesg

40. 7. Epistasis – Cucurbita pepop s as s Cu u b a p po