Unit 1 - Genetics

Question 1

Evolutionary Biology

Answer 1

The scientific study of the
evolutionary processes that produced the
diversity of life on Earth.

Question 2

Ecology

Answer 2

The scientific study of the interactions
between organisms and the living and nonliving
components of their environment

Question 3

Hypothesis

Answer 3

An explanation, based on
observations and assumptions, that leads to a
testable prediction.

Question 4

Experiment

Answer 4

A scientific test, carried out under
controlled conditions.

Question 5

Which laws govern Mendelian inheritance?

Answer 5

Probability

Question 6

Evolutionary Synthesis

Answer 6

What is Mendel’s model of inheritance combined with
Darwin’s theory of natural selection called?

Question 7

Inheritance

Answer 7

How traits are passed from
parents to offspring

Question 8

What is the blending model?

Answer 8

The idea that genetic material from two parents blends together. Leads to the loss of variation.

Question 9

What is the particulate model of inheritance?

Answer 9

The idea that parents pass
on discrete heritable
units.

Question 10

What is special about true breeding plants?

Answer 10

When self-pollinated, they produce offspring that all have identical traits.

Question 11

What are genes?

Answer 11

Discrete heritable units on chromosomes.

Question 12

Why did Mendel use peas?

Answer 12

Mating could be controlled, plants could be allowed to self-pollinate or could be cross-pollinated, short generation time, large numbers of offspring, many varieties

Question 13

What are alleles?

Answer 13

Alternative versions of
genes that account for variation
in inherited characters.

Question 14

What is a genotype?

Answer 14

Genetic makeup of an organism.

Question 15

What is a phenotype?

Answer 15

Physical appearance of an organism.

Question 16

What is being diploid?

Answer 16

Having two copies of each chromosome.

Question 17

What is the difference between heterozygote and homozygote?

Answer 17

Heterozygote - Organism has two alleles that are the different.
Homozygote - Organism has two alleles that are the same.

Question 18

What is a gamete?

Answer 18

A haploid reproductive cell, such as an egg or sperm, that is formed by meiosis.

Question 19

What is a monohybrid?

Answer 19

It means that the offspring is heterozygous for one character.

Question 20

What was Mendel’s law of independent assortment?

Answer 20

Each pair of alleles segregates independently of any other pair of alleles during gamete formation.

Question 21

A pea plant is heterozygous at the independent loci for flower color (Pp) and seed color (Yy). How many unique genotypes can it produce?

Answer 21

Four: pY, Py, py, PY

Question 22

What is a monohybrid cross?

Answer 22

A cross between two organisms that are heterozygous for the character.

Question 23

What is a dihybrid cross?

Answer 23

A cross between two organisms that are each heterozygous for both of the characters being followed.

Question 24

What is a multi-character cross?

Answer 24

Two or more independent monohybrid crosses occurring simultaneously.

Question 25

When does complete dominance occur?

Answer 25

When phenotypes of the heterozygote and dominant homozygote are identical.

Question 26

When does incomplete dominance occur?

Answer 26

The phenotype of F1 hybrids is somewhere between the phenotypes of the two parental varieties.

Question 27

When does co-dominance occur?

Answer 27

Two alleles affect the phenotype in separate, distinguishable ways.

Question 28

What is the Tay-Sachs disease?

Answer 28

It is caused by a single gene that has two alleles.

Question 29

What is the dominance relationship between the three main alleles for blood type?

Answer 29

IA and IB are codominant and are dominant to i

Question 29

What is a pleiotropy?

Answer 29

Genes that have multiple phenotypic effects.

Question 30

What happens in epistasis?

Answer 30

One gene affects the phenotype of another due to interaction of their gene products.

Question 31

What happens in polygenic inheritance?

Answer 31

Multiple genes independently affect a single trait.

Question 32

What is an example of epistasis?

Answer 32

In Labradors one gene determines the pigment color, while the other determines whether the pigment will be deposited in the hair.

Question 33

What is a qualitative character?

Answer 33

A character that has a few discrete types.

Question 34

What is a quantitative character?

Answer 34

A character that varies in the population along a continuum.

Question 35

What is an example of polygenic inheritance?

Answer 35

Height

Question 36

What is phenotypic plasticity?

Answer 36

The ability of an organism to change in response to stimuli or inputs from the environment.

Question 37

What is a multifactorial trait?

Answer 37

A trait that depends on multiple genes combined with environmental influences.

Question 38

What is an example of a multifactorial trait?

Answer 38

Human skin color

Question 39

What is a carrier?

Answer 39

An individual who is heterozygous at a given genetic locus for a recessively inherited disorder.

Question 40

What is a pedigree?

Answer 40

A family tree that describes the inheritance of a trait across generations.

Question 41

What is association study?

Answer 41

It is data to correlate genotypes and phenotypes across many individuals.

Question 42

What are non-coding elements?

Answer 42

Sequences and regions in the genome that do not code for protein or RNA.

Question 43

What is a mutation?

Answer 43

It is a change in DNA sequence relative to some standard or previously existing sequence. Mutations are always random.

Question 44

What is a mutant?

Answer 44

It is an individual whose genome contains a mutation at some location of interest.

Question 45

What is phenotypic variation?

Answer 45

It is variation in phenotypes among a group of organisms.

Question 46

What is genetic variation?

Answer 46

It is variation in mutations and/or alleles among members of a group of organisms.

Question 47

What are somatic mutations?

Answer 47

They are mutations that occur in the body tissues of an organism. They're not transmitted to the next generation.

Question 48

What are germline mutations?

Answer 48

They are mutations that occur in the gametes and are transmitted to offspring.

Question 49

What is a mutagen?

Answer 49

It is a substance or environmental factor that increases the rate at which mutations occur (causes mutations).

Question 50

What are error correction mechanisms?

Answer 50

They are cellular/molecular mechanisms that correct most errors in DNA replication/meiosis.

Question 51

What is non-disjunctions?

Answer 51

When chromosomes fail to correctly separate during meiosis.

Question 52

What are deleterious mutations?

Answer 52

Mutations that cause a decrease in an organisms fitness.

Question 53

What are beneficial mutations?

Answer 53

Mutations that cause an increase in an organisms fitness.

Question 54

What are neutral mutations?

Answer 54

Mutations that cause no change in an organisms fitness.