3A- Genetics

Question 1

What are genes?

Answer 1

Units of heredity that are made up of DNA

Question 2

Define inheritance/heredity

Answer 2

The passing of traits from parents to offspring

Question 3

What are traits?

Answer 3

Characteristics that are inherited from parents

Question 4

What are alleles?

Answer 4

Different forms of a gene

Question 5

Define genotype

Answer 5

The genetic makeup of an organism

Question 6

Define phenotype

Answer 6

The observable characteristics of an organism

Question 7

What does homozygous mean?

Answer 7

Having two identical alleles for a particular gene

Question 8

What does heterozygous mean?

Answer 8

Having two different alleles for a particular gene

Question 9

Define dominant allele

Answer 9

An allele that expresses its trait even in the presence of a recessive allele

Question 10

Define recessive allele

Answer 10

An allele that only expresses its trait when two copies are present

Question 11

What are Mendel’s Laws?

Answer 11

Three principles: Law of Segregation, Law of Independent Assortment, and Law of Dominance

Question 12

What does true breeding mean?

Answer 12

Organisms that produce offspring identical to themselves when self-fertilized

Question 13

What does cross breeding refer to?

Answer 13

Mating of two different true-breeding varieties

Question 14

What are the P, F1, and F2 generations?

Answer 14

P is the parental generation, F1 is the first filial generation, F2 is the second filial generation

Question 15

What is a monohybrid cross?

Answer 15

A cross between individuals that differ in one trait

Question 16

What do Punnett Squares help determine?

Answer 16

Genotype and phenotype ratios of offspring

Question 17

What is a dihybrid cross?

Answer 17

A cross between individuals that differ in two traits

Question 18

What is incomplete dominance?

Answer 18

A form of inheritance where the phenotype is a blend of the two parents’ traits

Question 19

What is codominance?

Answer 19

A form of inheritance where both alleles are fully expressed in the phenotype

Question 20

What are multiple alleles?

Answer 20

More than two alleles exist for a given gene in a population

Question 21

Define polygenic traits

Answer 21

Traits controlled by two or more genes

Question 22

What is the significance of blood type in heredity?

Answer 22

Blood type is determined by multiple alleles and can follow specific inheritance patterns

Question 23

What is the overall function of meiosis?

Answer 23

To produce gametes with half the number of chromosomes

Question 24

What is the difference between diploid and haploid?

Answer 24

Diploid cells have two sets of chromosomes, haploid cells have one set

Question 25

What occurs during tetrad formation?

Answer 25

Homologous chromosomes pair up during meiosis

Question 26

What is crossing over?

Answer 26

Exchange of genetic material between homologous chromosomes during meiosis

Question 27

What happens during Meiosis I?

Answer 27

Separation of homologous chromosomes (PMAT + C I)

Question 28

What happens during Meiosis II?

Answer 28

Separation of sister chromatids (PMAT + C II)

Question 29

What can influence gene expression?

Answer 29

Environmental factors

Question 30

What is gene linkage?

Answer 30

The tendency of genes located close together on a chromosome to be inherited together

Question 31

What is a pedigree?

Answer 31

A diagram that shows the occurrence of a genetic trait in several generations of a family

Question 32

What does the Law of Segregation state?

Answer 32

Each individual possesses two alleles and only one is passed to offspring

Question 33

What does the Law of Independent Assortment state?

Answer 33

The inheritance of one trait does not influence the inheritance of another trait