gr 10-bio (unit 1.2)

Question 1

what is a trait?

Answer 1

an inherited characteristic, such as eye colour or hair colour

Question 2

What did Gregor Mandel discover and how did he experiment?

Answer 2

-made the first discoveries about how
traits are passed from one generation to the next
-In the 1860s, he experimented with pea plants

Question 3

How do pea plants reproduce?

Answer 3

• Pea plants reproduce by sexual reproduction, but they usually self-pollinate.
• Self-pollination occurs when a male gamete within a flower combines with a female gamete in the same flower

Question 4

what is cross-pollination?

Answer 4

when a male gamete from one flower combines

with a female gamete from a flower of a different plant.

Question 5

true-breeding

Answer 5

plants that consistently produce offspring with only one form of a trait

Question 6

The law of segregation

Answer 6

• The law of segregation describes the genetic basis for how characteristics are inherited
• it states that alleles for each inherited trait separate, or segregate from each other
• Each gamete carries one allele for each characteristic
• When fertilization takes place, each gamete contributes its allele for a characteristic

Question 7

dominant and recessive genes

Answer 7

dominant- the allele or trait that is expressed, regardless(upper case letter) (is dominant over recessive)
recessive- the allele or trait that is expressed only when two alleles are present (lower case letters)

Question 8

what is a genotype and a phenotype

Answer 8

genotype: is the specific combination of alleles
it has for a trait (eg. Bb)
phenotype: is the physical expression of an organism’s trait (eg. purple flower)

Question 9

homozygous and heterozygus info

Answer 9

homozygous: when two alleles are the same. eg. BB or bb
heterozygous: two different alleles for a trait. eg. Bb

Question 10

monohybrid cross

Answer 10

a cross between two traits

Question 11

dihybrid cross

Answer 11

a cross between four traits

Question 12

codominance

Answer 12

• both alleles are fully expressed

- eg. a cow animal is a heterozygous codominance because it has white hairs and black hairs (HwHb)

Question 13

incomplete dominance

Answer 13

• both alleles mix
• eg. a white and red flower mix and creates a pink flower
• so if it was HrHw it would be a pink flower

Question 14

sex-linked traits

Answer 14

• traits controlled by x and y chromosome
• traits controlled by genes on the X chromosome are called X-linked traits
• because genetic males (XY) have only one X chromosome, they are affected by recessive X-linked traits more often than are genetic females because they have XX so a dominant trait can mask the recessive one