Genetics

Question 1

Hereditary

Answer 1

the passing of traits from parent to offspring

Question 2

Genetics

Answer 2

branch of biology that studies the ways in which hereditary info is passed from parents to offspring

Question 3

Gregor Mendel

Answer 3

monk who began the study of hereditary by carrying out experiments using pea plants

Question 4

Why were peas useful to study?

Answer 4

Several traits of the peas only existed in two forms, mating can be easily controlled, and peas grow easily/mature fast/produce many offspring

Question 5

Why can pea mating be easily controlled?

Answer 5

The female and male parts are enclosed within the same flower

Question 6

How do flowers (peas) fertilize?

Answer 6

Either self fertilize or cross pollination

Question 7

what is cross pollination?

Answer 7

transferring the pollen from one plant to another flower on a different plant

Question 8

monohybrid cross

Answer 8

studies inheritance of only one pair of contrasting traits

Question 9

What did Mendel begin his experiments by using?

Answer 9

a monohybrid cross

Question 10

True breeding plant

Answer 10

Only produces offspring of the same type

Question 11

What did Mendel do to ensure that each plant was true breeding?

Answer 11

He allowed each plant to self pollinate for several generations

Question 12

What is the P generation?

Answer 12

The parental generation, or the true breeding plants that produce more of themselves

Question 13

What was the F1 generation?

Answer 13

The first filial generation

Question 14

What did the F1 generation result from?

Answer 14

Cross pollination of the two, different, P generation plants (by Mendel)

Question 15

What happened to the F1 generation?

Answer 15

They were allowed to self pollinate, resulting in the F2 generation

Question 16

What were Mendel’s results with the F1 generation?

Answer 16

They all had only one trait. In this example, all the flowers were purple-the white trait had disappeared.

Question 17

What were Mendel’s results with the F2 generation?

Answer 17

The missing trait had reappeared. (705 purple:224 white) (3.15:1)

Question 18

What did Mendel’s experiment prove instead?

Answer 18

Peas (and humans) have separate heritable factors for each trait, one from each parent.

Question 19

What did Mendel disprove with his experiments?

Answer 19

Scientific belief that an offspring’s traits were a blend of the parents.

Question 20

What are the separate heritable factors for each trait called?

Answer 20

Genes.

Question 21

How many copies of a gene does an individual have, and where do they get them according to Mendel’s Hypotheses?

Answer 21

An individual has two copies of every gene, one from each parent

Question 22

What are alleles?

Answer 22

Alternative versions/copies of the same gene

Question 23

What is the example of an allele in relation to Mendel’s experiment?

Answer 23

Purple vs white flowers

Question 24

What happens when there are two different alleles in an organism?

Answer 24

Only one will be expressed

Question 25

What is a dominant allele?

Answer 25

Observable/expressed

Question 26

What is a recessive allele?

Answer 26

Trait that isn't expressed in presence of dominant

Question 27

Which alleles (dominant v. recessive) were present in Mendel's experiments?

Answer 27

One dominant, one recessive

Question 28

Did Mendel's hypotheses include alleles and dominance?

Answer 28

Yes

Question 29

Gametes formed by meiosis have how many alleles for each trait? Was this mentioned in Mendel's experiments?

Answer 29

Only one, and yes

Question 30

What happens to the alleles when gametes unite in fertilization?

Answer 30

Each gamete contributes one allele, their allele

Question 31

How are dominant alleles represented?

Answer 31

Write the first letter of trait as capital

Question 32

How are recessive alleles represented?

Answer 32

First letter of dominant trait, but lowercase

Question 33

Homozygous

Answer 33

Individuals that have two alleles for the same trait

Question 34

Heterozygous

Answer 34

Individuals that have two different alleles

Question 35

Which allele is expressed in heterozygous individuals?

Answer 35

Dominant

Question 36

Phenotype

Answer 36

Appearance

Question 37

Genotype

Answer 37

Alleles an individual has

Question 38

What is the law of segregation?

Answer 38

Two alleles separate from one another when gametes are formed

Question 39

What does the law of segregation explain?

Answer 39

the behavior of chromosomes during meiosis

Question 40

What are the laws of heredity?

Answer 40

The law of segregation, law of independent assortment

Question 41

What did Mendel do after studying monohybrid crosses

Answer 41

He investigated whether the inheritance of one trait (like flower color) affected inheritance of a different trait (like plant height)

Question 42

How did Mendel investigate whether inheritance of certain traits were linked?

Answer 42

He experimented with dihybrid crosses

Question 43

What are dihybrid crosses?

Answer 43

Crosses that consider 2 pairs of contrasting traits

Question 44

What is the law of independent assortment?

Answer 44

The inheritance of one trait does not influence others bc the alleles of different genes separate independently from one another during gamete formation

Question 45

Test cross

Answer 45

an individual whose phenotype is dominant but genotype is unknown is crossed w/ a homozygous recessive individual

Question 46

Why would one use a test cross?

Answer 46

To know whether an organism w/ a dominant phenotype is heterozygous or homozygous for a trait

Question 47

How do the results of a test cross exemplify the answer?

Answer 47

If all offspring exhibit this dominant phenotype, the genotype must be homozygous for that allele. If half offspring exhibit both phenotypes, it must be heterozygous.

Question 48

Incomplete dominance

Answer 48

The inheritance of a dominant trait and a recessive trait results in a blending of traits that isn't exactly like either parent

Question 49

Codominance

Answer 49

two dominant traits, both visible

Question 50

How is codominance often represented?

Answer 50

Capital letters w/ superscripts

Question 51

How is codominance found in humans?

Answer 51

Blood type-AB

Question 52

Multiple Alleles

Answer 52

more than 2 possible alleles for a certain trait (individual only inherits two possibilities)

Question 53

Multiple Alleles-blood type

Answer 53

3 different alleles for blood, a, b, and o, but you can only have 2

Question 54

What do the A and B alleles code for?

Answer 54

the presence of certain markers on the surface of red blood cells

Question 55

What does the O allele code for?

Answer 55

No markers

Question 56

Which blood type alleles are dominant?

Answer 56

A, B

Question 57

Which blood type alleles are recessive?

Answer 57

O

Question 58

How does AB phenotype occur?

Answer 58

If both A and B alleles are present, since they're codominant

Question 59

Setting up Punnett Square-dihybrid crosses

Answer 59

1. determine genotype of parents 2. determine possible gametes 3. write these gametes on the top and left of a 16sq punnett square 4. complete the punnett square

Question 60

What is an autosome?

Answer 60

A non-sex chromosome

Question 61

Autosomal trait

Answer 61

A trait located on an autosome

Question 62

Sex-linked/X-linked trait

Answer 62

trait whose allele is located on the X chromosome

Question 63

Will a male who carries the recessive allele on his X chromosome exhibit the condition?

Answer 63

Yes, bc he only has one X

Question 64

Will a female who carries the recessive allele on one of her chromosome exhibit the condition?

Answer 64

No, only if it is on both X chromosomes. Otherwise, she will just carry it.

Question 65

How can you learn about the chances of passing down a trait within your own family?

Answer 65

A pedigree

Question 66

Pedigree

Answer 66

family history constructed by geneticists that shows how a trait is inherited over several generations

Question 67

In what case might a pedigree be helpful?

Answer 67

If the trait is a genetic disorder and the family members want to know if they are carriers, or if their children can get the disorder

Question 68

How to tell by a pedigree if a trait is autosomal or sex linked?

Answer 68

Sex linked usually appears in more males

Question 69

How to tell by a pedigree if a trait is dominant or recessive?

Answer 69

Dominance will appear in every generation (usually) while recessive can appear in one, then skip a generation, then appear in a later generation

Question 70

How to tell by a pedigree if a trait is homozygous or heterozygous?

Answer 70

If the phenotype shows the dominant allele, genotype must be homozygous dominant or heterozygous. If phenotype is recessive, genotype must be homozygous recessive.

Question 71

Blood type O

Answer 71

ii

Question 72

Blood type A

Answer 72

IAi or IAIA

Question 73

Blood type B

Answer 73

IBi or IBIB

Question 74

What is blood type AB

Answer 74

IAIB

Question 75

What is dominance in blood type?

Answer 75

A and B over O, codominance together

Question 76

Polygenic trait

Answer 76

Trait influenced by several genes

Question 77

Where can polygenic traits be located?

Answer 77

Same chromosome or different chromosomes

Question 78

Why do many different polygenic combinations occur in offspring?

Answer 78

Independent assortment, crossing over

Question 79

What can an individual's phenotype also depend on?

Answer 79

Environmental conditions