Unit 4 pt 3

Question 1

Genetics is the study of ______ and _____, focusing on how DNA codes for proteins and is passed to offspring.

Answer 1

genes and heredity

Question 2

_____ examines genes (DNA segments coding for proteins) and heredity (gene transmission across generations), foundational to understanding traits.

Answer 2

Genetics

Question 3

______ is the process of passing genetic information from parents to offspring through generations.

Answer 3

Heredity

Question 4

____ describes how genes, carried in DNA, are inherited, determining offspring traits like flower color or height.

Answer 4

Heredity

Question 5

______ conducted pea plant experiments in the 1800s, laying the foundation for modern genetics.

Answer 5

Gregor Mendel

Question 6

_____’s breeding experiments with pea plants established key inheritance principles, such as dominant and recessive traits.

Answer 6

Mendel

Question 7

The physical characteristics of an organism, such as purple flowers, are called its ______.

Answer 7

Phenotype

Question 8

____ refers to observable traits, determined by the genotype (genetic makeup) and sometimes environment.

Answer 8

Phenotype

Question 9

The genetic makeup of an organism, consisting of its alleles, is called its ______.

Answer 9

Genotype

Question 10

____ is the set of genes (alleles) an organism carries, influencing its phenotype (e.g., PP, Pw, or ww for flower color).

Answer 10

Genotype

Question 11

A ______ organism consistently produces offspring with the same traits, like purple flowers across generations.

Answer 11

true-breeding

Question 12

True-breeding organisms (e.g., PP for purple flowers) pass ____ traits to offspring when self-bred or crossed with similar organisms.

Answer 12

identical

Question 13

Crossing two true-breeding parents to produce offspring is called ______.

Answer 13

Hybridization

Question 14

_____ combines different true-breeding strains (e.g., purple x white flowers) to create hybrid offspring with mixed traits.

Answer 14

Hybridization

Question 15

The ______ generation is the parental generation in a genetic cross.

Answer 15

P

Question 16

The ____ generation consists of the initial parents crossed in a genetic experiment, producing the F1 generation.

Answer 16

P (parental)

Question 17

The first generation of offspring from a genetic cross is called the ______ generation.

Answer 17

F1

Question 18

The ____ generation, results from crossing the P generation, showing traits based on parental alleles.

Answer 18

F1 (first filial), children

Question 19

The second generation of offspring, or “grandchildren,” is called the ______ generation.

Answer 19

F2

Question 20

The _____ generation comes from crossing F1 individuals, revealing trait ratios (e.g., 3:1 for dominant-recessive).

Answer 20

F2 (second filial)

Question 21

A ______ trait is expressed when present, masking the recessive trait in heterozygous organisms.

Answer 21

Dominant

Question 22

____ traits (e.g., purple flowers, P) appear in the phenotype when paired with a recessive allele (e.g., white, w).

Answer 22

Dominant

Question 23

A recessive trait is hidden in the presence of a dominant allele and only appears in ____ recessive organisms.

Answer 23

homozygous

Question 24

____ traits (e.g., white flowers, w) are expressed only when both alleles are recessive (ww).

Answer 24

Recessive

Question 25

An organism with two identical alleles for a trait (e.g., PP or ww) is ______.

Answer 25

Homozygous

Question 26

____ organisms have two copies of the same allele, either dominant (PP) or recessive (ww), determining the trait.

Answer 26

Homozygous

Question 27

An organism with two different alleles for a trait (e.g., Pw) is ______.

Answer 27

Heterozygous

Question 28

____ organisms carry one dominant and one recessive allele, expressing the dominant trait (e.g., purple flowers in Pw).

Answer 28

Heterozygous

Question 29

Different versions of a gene, such as P or w for flower color, are called ______.

Answer 29

Alleles

Question 30

____ are variants of a gene that cause trait differences (e.g., P for purple, w for white flowers).

Answer 30

Alleles

Question 31

Mendel’s first principle states that ______ account for variations in traits, like purple vs. white flowers.

Answer 31

Alleles

Question 32

_____ create trait diversity, as seen in Mendel’s pea plants (e.g., round vs. wrinkled seeds).

Answer 32

Alleles (gene variants)

Question 33

According to Mendel, organisms inherit ______ alleles for each trait, one from each parent.

Answer 33

two

Question 34

Each trait is controlled by ___alleles, delivered via gametes during reproduction, shaping the organism’s genotype.

Answer 34

two

Question 35

During ______, alleles for a trait separate into different gametes, ensuring each gamete carries one allele.

Answer 35

meiosis

Question 36

________ states that alleles segregate during meiosis, so each gamete receives one allele per trait.

Answer 36

Mendel’s Law of Segregation

Question 37

A ______ square is a diagram used to predict offspring genotypes and phenotypes from parental alleles.

Answer 37

Punnett

Question 38

_____ squares visualize inheritance probabilities, showing possible genotype combinations (e.g., Pw, ww) and phenotypes.

Answer 38

Punnett

Question 39

: In Punnett square notation, the dominant allele is typically represented by a ______ letter (e.g., P).

Answer 39

capital

Question 40

Capital letters denote _____ alleles (e.g., P for purple), while lowercase letters denote _____ alleles (e.g., w for white).

Answer 40

Capital letters denote dominant alleles (e.g., P for purple), while lowercase letters denote recessive alleles (e.g., w for white).

Question 41

In a Pw x ww cross, the offspring have a ______% chance of being purple and a ______% chance of being white.

Answer 41

50, 50

Question 42

In ______ dominance, one allele fully masks the other, producing only the dominant phenotype (e.g., purple flowers).

Answer 42

complete

Question 43

______ ______, as in Mendel’s peas, means the dominant allele (P) fully hides the recessive allele (w) in heterozygous organisms.

Answer 43

Complete dominance

Question 44

In ______ dominance, neither allele is fully dominant, resulting in an intermediate phenotype (e.g., pink snapdragons).

Answer 44

Incomplete dominance

Question 45

_____ _____ blends traits in heterozygotes (e.g., red [RR] x white [WW] snapdragons produce pink [RW] offspring).

Answer 45

Incomplete dominance

Question 46

In ______ dominance, both alleles are expressed without blending, showing both traits (e.g., blue-and-white bird feathers).

Answer 46

Codominance

Question 47

_____ allows both alleles to be expressed distinctly in heterozygotes (e.g., blue and white feathers appear together, not blended).

Answer 47

Codominance

Question 48

Traits like human eye color, controlled by ______ genes, show variation due to incomplete or codominance.

Answer 48

multiple

Question 49

____ traits (e.g., eye color, skin color) produce varied phenotypes (e.g., shades of blue, brown) due to complex allele interactions.

Answer 49

Multi-gene