Chapter 6 (part 2)

Question 1

Mendels First Law

Answer 1

segregation

Question 2

what is segregation

Answer 2

The two alleles of a trait separate from each other during the formation of gametes, so half of the gametes carry one copy and half carry the other copy.
* Occurs because diploid germ cells form haploid gametes, and each gamete can only have one of each homologous chromosome pair.

Question 3

Mendels Second Law

Answer 3

independent assortment

Question 4

what is independent assortment

Answer 4

Which homologous chromosomes segregate into each gamete is random

Question 5

dihybrid cross

Answer 5

if the genes of two different traits are on different chromosomes

Question 6

often phenotype expression is not as simple as dominant and recessive inheritance. alternate patterns are referred to as

Answer 6

non-mendelian inheritance

Question 7

polygenic

Answer 7

Inheritance that involves multiple genes acting together

Question 8

continuous variation

Answer 8

Most traits are determined by multiple genes and show a range small differences between two extremes

Question 9

examples of polygenic traits

Answer 9

• Height
• Weight
• Skin colour
• Intelligence

Question 10

diseases that are influenced by multiple genes

Answer 10

• Cancer
• Diabetes
• Cleft palate
• Schizophrenia

Question 11

Pleiotropic Inheritance

Answer 11

one gene causes multiple variations
of phenotype

Question 12

incomplete dominance

Answer 12

Not all alleles are fully dominant or fully recessive.
* In some cases, alleles exhibit incomplete dominance and produce a heterozygous phenotype that is intermediate between those of the parents

Question 13

codominance

Answer 13

A gene may have more than two alleles in a population.
* Sometimes in heterozygotes there is not a dominant allele. Instead – both alleles are expressed.

Question 14

Blood types are…

Answer 14

codominant

Question 15

what are the 4 different phenotypes or blood types?

Answer 15

A, B, AB, and O

Question 16

what blood types are dominant over the other?

Answer 16

A, and B are dominant over O (A and B are co-dominant)

Question 17

anitgens

Answer 17

cell-surface proteins, glycoproteins, or lipoproteins that allow these cells to be identified

Question 18

why is it that as we grow and develop, the antigens on our own cells are shown to the immune system?

Answer 18

because this way it teaches our immune system that it is our cells. keeps the immune system from attacking and killing cells that make up us.

Question 19

Type A has the “A” antigen, and therefore makes…

Answer 19

“B” antibodies

Question 20

Type B has the “B” antigen and therefore makes…

Answer 20

“A” antibodies

Question 21

Type AB has both antigens and makes…

Answer 21

no antibodies

Question 22

Type O has no antigens and makes…

Answer 22

both antibodies

Question 23

which blood type is the universal donor?

Answer 23

type O

Question 24

Epistasis

Answer 24

When the phenotype of one gene is dependent on the effect of one or more ‘modifier genes

Question 25

X linked traits

Answer 25

Inheritance depended on sex.

Question 26

a fly with two X chromosomes is

Answer 26

female

Question 27

A fly with an X and Y chromosome is

Answer 27

male

Question 28

why are X-linked diseases more common in men?

Answer 28

• they are on the X chromosome
• Males only have to inherit one disease allele for it to be expressed
• The ‘Y’ chromosome often does not offer a competing allele

Question 29

linkage

Answer 29

genes located close together on a chromosome tend to segregate together

Question 30

The farther two genes are from each other on the same chromosome, the more likely…

Answer 30

crossing over will occur
between them