Chapter 2.3 At the organismal level

Question 1

what part of the flower is the male part and produces pollen

Answer 1

stamens

Question 2

what part of the flower is the female part and bears eggs

Answer 2

carpels

Question 3

what is the meaning of cross-pollination

Answer 3

• immature stamens removed
• pollen from another plant dusted onto flowers

Question 4

what are true breeding plants

Answer 4

• plants self pollinated over many gens

Question 5

what is the meaning of hybridization

Answer 5

• crossing of two true breeding varieties

Question 6

what are the key points of mendel’s law of segregation

Answer 6

• gametes only carry one allele per gene
• heritable factor from recessive trait hidden when recessive trait present
• reappearance of recessive trait indicates = trait doesn’t disappear/dilute
• 3:1 ratio found for characters in other F2 gens

Question 7

difference between homozygous and heterozygous

Answer 7

Homozygous
- has two identical alleles for one gene
- all gametes contain same allele
Heterozygous
- has two different alleles for one gene
- half will have one allele and the half will have the other

Question 8

difference between phenotype and genotype

Answer 8

Phenotype
- observable traits
Genotype
- genetic makeup causing the phenotype

Question 9

what is a monohybrid

Answer 9

heterozygous for one character (Yy) 1 allele = 1 character

Question 10

what is a dihybrid

Answer 10

individuals heterozygous for two characters (YyRr)

Question 11

what is mendel’s law of independent assortment

Answer 11

each pairs of alleles segregates independently off each other during gamete formation

Question 12

how do you use the multiplication rule to calculate the probability of an event

Answer 12

multiply probability of each event

Question 13

differentiate complete dominance, incomplete dominance and codominance

Answer 13

complete dominance : one allele completely dominant over recessive allele
incomplete dominance : phenotype of heterozygote is intermediate between phenotypes (dominant allele isn’t completely expressed)
codominance : 2 alleles each affect phenotype in separate ways, phenotype of both alleles exhibited in heterozygote

Question 14

what are the 4 phenotypes in blood groups and what does A and B refer to specifically

Answer 14

A, B, AB and O
A and B refer to carbohydrates on surface of red blood cells

Question 15

how many different genotypes exist in blood groups

Answer 15

six different genotypes :
- IA IA or IA i for A phenotype
- IB IB or Ib i for B phenotype
- IA IB for AB phenotype
- ii for O phenotype

Question 16

what is the universal donor and universal recipient

Answer 16

Donor : O- because no structure (carbohydrates) that requires certain compatibility
Recipient : AB+

Question 17

define pleiotropy

Answer 17

• ability of a single gene to have multiple phenotypic effects
• eg. gene that determines flower colour in pea but also affects colour of outer coating

Question 18

what is epistasis

Answer 18

• when one gene depends on another gene for it to be expressed
• eg. activation or deactivation of a certain phenotype

Question 19

what are polygenic traits and what does it mean

Answer 19

multiple genes coding for one trait, meaning there’s no single pair of alleles coding for that trait and it requires multiple pairs ignoring environmental factors.
eg. height in humans

Question 20

how can environmental factors impact phenotype and make two species with same genotype vary

Answer 20

• some phenotypes varies due to environment
  eg. skin colour
• flowers with same genotype can looks different depending on the acidity of the soil and aluminum content they grew in

Question 21

what is a pedigree analysis

Answer 21

it’s a diagram of family tree showing occurrence of heritable characters in parents and offsprings over several gens

Question 22

what are the conventional symbols for male/female and affected/unaffected

Answer 22

male: square
female: circle
affected: coloured/filled
unaffected: empty

Question 23

what is the purpose of pedigrees

Answer 23

they help calculate the probability of future offspring having particular genotype and phenotype

Question 24

what is a wildtype

Answer 24

a phenotype most commonly observed in natural pop