Chapter 8: Inheritance, genes, and chromosmes

Question 1

The “Particulate theory of inheritance” was founded by?

Answer 1

Gregor Mendel

particles = genes

Question 2

What experiments did Gregor Mendel do?

Answer 2

Breeding experiments with pea plants

Question 3

Why did Mendel use pea plants?

Answer 3

1. Can mate with others(cross-pollinate) or with self (self-pollinate)
2. Produce large numbers of offspring
3. Fast generation time: time it takes for one seed to grow and yield new seeds

Question 4

What are the three names of generations? ONLY FOR PLANTS

Answer 4

1. P
2. F1
3. F2

Question 5

What is a monohybrid cross?

Answer 5

Only one gene invovled

Question 6

What is a dihybrid cross?

Answer 6

Dihybrid cross is a cross between two individuals with two observed traits that are controlled by two distinct genes.

Question 7

What is a hybrid cross?

Answer 7

1. Mate two different homozygotes to get a heterozygote/hybrid
2. Mate the hybrids/heterozygotes

Question 8

How do you decide which plant is the mother?

Answer 8

Wherever the pollen is moving will be the mother

Question 9

Which organelles contain their own DNA?

Answer 9

Mitochondria and chloroplasts

Question 10

DNA outside the nucleus is inherited through the ____(1). This is known as __(2)

Answer 10

(1) mother
(2) cytoplasmic inheritance

Question 11

Genes are ____(1). Each gene is a small stretch of a ___(2), and ___(2) are made of ___(3).

Answer 11

(1) units of inheritance
(2) Chromsomes
(3) DNA

Question 12

___(1) are forms of a gene. Each ___(1) is generally either dominant or ___(2).

Answer 12

(1) Allele
(2) Recessive

Question 13

The __(1) of an organism tell you what genes and alleles it has. An organism with two copies of the same allele is ___(2) while an organism with two different alleles is ___(3)

Answer 13

(1) genotype
(2) homozygous
(3) heterozygous

Question 14

The ___(1) of an organism tells you what appearance it has.

Answer 14

(1) phenotype

Question 15

What was mendel’s particulate theory?

Answer 15

The units responsible for inheritance are discrete particles that exist within an organism in pairs and separate during gamete formation.

Question 16

ALWAYS CHECK IF THE QUESTION SI AKSING TO EXPRESS THE RESULTS OF A PUNNETT SQUARE IN PERCENT, FRACTION, DECIMAL, ETC

Answer 16

RAWR

Question 17

The law of segregation explains what happens to ___(1). The law of independent assortment explains what happens to ___(2)

Answer 17

(1) a single gene during meiosis
(2) two genes during meiosis

Question 18

What sis Mendel use to illustrate independent assortment?

Answer 18

a dihybrid cross

Question 19

Why is the law of independent assortment?

Answer 19

Alleles of different genes assort into gametes independently of each other

Question 20

What is the law of segregation

Answer 20

T

Question 21

To determine the probability that two independent events will both happen…..

Answer 21

MULTIPLY the probabilities of the individual events

Question 22

To determine the probability that one event OR another will happen ….

Answer 22

add the probabilities of the individual events

Question 23

Human geneticists rely on ___(1). ___(1) show phenotype segregation in several generations of related individuals.

Answer 23

(1) Pedigrees

Question 24

What five things have we learned since Mendel?

Answer 24

1. We cna extend mendel’s principles to study organisms that cannot be self-crossed
2. Simple dominance is not always the case
3. Most traits result from multiple genes and/or interactions with the environment
4. Sometimes, the law of independent assortment is “violated” through linkage and sex linkage
5. DNA outside the nucleus is inherited through the mother

Question 25

What is the wild type?

Answer 25

The usual phenotype

Question 26

What is the mutant?

Answer 26

unusual phenotype

Question 27

What is the naming convention for humans?

Answer 27

Generation I, Generation II, Generation III

Question 28

How do you determine if a trait is dominant or recessive?

Answer 28

Dominant:
- every affected kid has at least 1 affected parent, tends not to skip generations

Recessive:
- Affected kid may gave 2 unaffected parents, trait tends to skip generations

Question 29

Simple dominance is not always the case. What are the two other types of dominance?

Answer 29

1. Incomplete dominance: a blending of the two alleles that results in a third phenotype that doesn’t look like either of the parents.
2. Codominance(ex. blood types): both parent phenotypes show up together on the offspring.

Question 30

What is linkage?

Answer 30

Genes on the same chromosome do not assort independently

Question 31

Just because two genes are on the same chromosome _____(1) mean they will always be inherited together.

Answer 31

(1) doesn’t

Question 32

How does distance affect the likelihood that two genes will be inherited together?

Answer 32

Genes that are close together tend to be inherited together. The farther apart on the same chromosome two genes are the more likely the genes will be separated during crossing over/recombination

Question 33

What does hemizygous mean?

Answer 33

only having one allele, as is the case with male sex-linked chromosomes

Question 34

What is the trend with sex-linked inheritance?

Answer 34

More males are affected than females.