TEAS 7 - Science (Mendel's Laws of Inheritance)

Question 1

___ is the process by which genetic information is passed down from parents to their offspring through DNA.

Answer 1

Inheritance

Question 2

When fertilization occurs, the offspring receives ___ allele from each parent, thus restoring the pair.

Answer 2

1

Question 3

Mendel observed that each individual has ___ copies of each gene, which we now call alleles.

Answer 3

2

Question 4

During the formation of gametes (sperm and egg cells), these alleles ___, with each gamete receiving only one copy of each gene.

Answer 4

separate

Question 5

What is Mendel’s Second Law, the Law of Independent Assortment?

Answer 5

this law states that the inheritance of one gene does not influence the inheritance of another gene

Question 6

Which law states that the inheritance of one gene does not influence the inheritance of another gene

Answer 6

Mendel’s Law of Independent Assortment

Question 7

Mendel found that different traits, such as flower color and seed shape, were inherited ___ from each other.

Answer 7

independently

Question 8

This is why offspring typically have a ___ of characteristics from their parents –– each trait is passed along ___ and trait dominance is what determines which traits are expressed in the offspring.

Answer 8

combination

independently

Question 9

Are the genes for eye and hair color inherited together?

Answer 9

No

*If one of your parents has brown hair and green eyes, it does not mean that if you inherit their gene for brown hair, you will also inherit their gene for green eyes.

Question 10

The alleles for different genes ___ and assort into gametes ___ during meiosis. This means that the inheritance of one trait does ___ affect the inheritance of another trait, and that they are passed down randomly.

Answer 10

segregate

independently

not

Question 11

If one of your parents has brown hair and green eyes, does it mean that if you inherit their gene for brown hair, you will also inherit their gene for green eyes?

Answer 11

No

*The inheritance of one trait does not affect the inheritance of another trait, and they are passed down randomly. For instance, eye and hair color are not inherited together.

Question 12

So, how can we predict which inherited traits will “show up” in an offspring?

Answer 12

trait dominance

Question 13

A ___ is an organism’s genetic makeup. It is the combination of alleles an individual has inherited for a specific trait.

Answer 13

genotype

Question 14

We represent an individual’s genotype by ___ which represent the two alleles for one gene

Answer 14

letters

Question 15

For example, the two alleles for the flower color of Mendel’s pea plants can be represented by P and p. The capital P represents the ___ allele and the lowercase p represents the ___ allele.

Answer 15

dominant

recessive

Question 16

Can we “see” an organism’s genotype?

Answer 16

no

*the traits that we can observe in an individual are known as the phenotype.

Question 17

The traits that we can observe in an individual are known as the ___.

Answer 17

phenotype

Question 17

A phenotype refers to the ___ physical characteristics of an individual. It represents the actual ___ of genes and is influenced by the genotype.

Answer 17

observable

expression

Question 18

How do genotypes influence an organism’s phenotype?

Answer 18

through dominance

Question 18

The ___ allele is the trait that will be expressed if this allele is present in a genotype.

Answer 18

dominant allele

Question 19

The ___ allele is the trait that will not be expressed if this allele is present in a genotype with a dominant allele.

Answer 19

recessive allele

Question 19

___ refers to a genotype in which an individual has two identical alleles for a specific trait. These alleles can be either dominant or recessive.

Answer 19

Homozygous

Question 20

___ ___ is represented by two capital letters. In this case, both alleles are dominant.

Answer 20

Homozygous Dominant

Question 20

What are the 2 types of homozygous genotypes?

Answer 20

• homozygous dominant
• homozygous recessive

Question 21

___ ___ is represented by two lowercase letters. In this case, both alleles are recessive

Answer 21

Homozygous Recessive

Question 22

For example, a genotype of pp would be ___ ___, where both alleles are for white flowers.

Answer 22

homozygous recessive

Question 22

For example, if we consider the gene for flower color in pea plants, a genotype of PP would be ___ ___, where both alleles are for purple flowers.

Answer 22

homozygous dominant

Question 23

___ refers to a genotype in which an individual has two different alleles for a specific trait. In other words, the alleles are not identical. The genotype contains both a dominant allele and a recessive allele.

Answer 23

Heterozygous

Question 24

Heterozygous genotypes are represented by one ___ letter and one ___ letter.

Answer 24

capital lowercase

Question 25

For example: a genotype of Pp would be ___. In this case, the dominant allele (P) is paired with the recessive allele (p), resulting in a purple flower phenotype since the ___ allele masks the ___ allele.

Answer 25

heterozygous dominant recessive

Question 26

Since the ___ allele will always be the one that is expressed, the recessive alleles will only be expressed when paired together.

Answer 26

dominant

Question 27

When will recessive alleles be expressed?

Answer 27

when paired together

Question 28

If an individual’s genotype is a combination that includes a B for brown eyes, what genotype must they have to inherit brown eyes?

Answer 28

BB and Bb

Question 28

If an individual’s genotype is a combination that includes a B for brown eyes and b for blue eyes, what genotype must they have to inherit blue eyes?

Answer 28

an individual would only have blue eyes if their genotype is bb *blue eyes are recessive, so the offspring with blue eyes will have to inherit a recessive allele from each parent

Question 29

What tool makes it easier to understand inheritance?

Answer 29

a Punnett Square

Question 29

Remember that each parent has ___ alleles for a particular gene, which could be represented by letters.

Answer 29

2

Question 30

Each square in the Punnett square represents a possible ___ of the offspring. By looking at the combinations of letters in the square, we can determine the genotypes and ___ (physical appearance) of the offspring.

Answer 30

genotype phenotype

Question 30

Let's say that a Punnett Square has the genotypes BB, Bb, Bb, and bb. What genotypes represent the phenotype for Brown eyes?

Answer 30

BB, Bb, Bb

Question 31

Let's say that a Punnett Square has the genotypes BB, Bb, Bb, and bb. What genotypes represent the phenotype for blue eyes?

Answer 31

bb

Question 32

Let's say that a Punnett Square has the genotypes BB, Bb, Bb, and bb. What is the probability that the offspring having brown eyes?

Answer 32

3 out of 4 (75%)

Question 33

Let's say that a Punnett Square has the genotypes BB, Bb, Bb, and bb. What is the probability that the offspring having blue eyes?

Answer 33

1 out of 4 (25%)

Question 34

Which of the following statements correctly describes the inheritance of traits in humans?

Answer 34

Both parents produce different haploid gametes via meiosis that fertilize to form a diploid zygote.

Question 35

The presence of genes contributes to the entire cell's functioning and unique character traits. How are these genes inherited?

Answer 35

The two alleles in a particular gene pair are inherited, one from the mother and one from the father, during fertilization.

Question 36

What are alleles?

Answer 36

Alleles are an alternate form of a gene.

Question 37

Which of the following correctly defines genotype?

Answer 37

Genotype is a specific combination of alleles found in an individual.

Question 38

The presence of two varying alleles of a gene is called a ____________ individual.

Answer 38

Heterozygous

Question 39

Which of these statements describes a dominant allele?

Answer 39

A dominant allele always expresses itself phenotypically even in the presence of other alleles.

Question 40

Which of the following is a correct definition of recessive allele?

Answer 40

Recessive alleles are the ones that express phenotypically only when two identical copies of alleles are present.

Question 41

Which of these is seen in the human blood group system?

Answer 41

Multiple allelism Multiple allelism is seen when more than two alleles are present. The blood group system in humans has three alleles, that are A, B and O.

Question 42

When the phenotype of two alleles is expressed partially, its called:

Answer 42

Incomplete dominance *Incomplete dominance is when the phenotype is expressed partially by two different alleles. It presents as a “blend” of the two characteristics, such as parents with red and white flowers producing offspring with pink flowers.

Question 42

Which of the following correctly describes the law of segregation?

Answer 42

It states that allele pairs segregate during gametogenesis and reunite randomly during the fertilization process.

Question 43

Which of the following best describes the law of independent assortment?

Answer 43

It states that the different traits or pairs of traits segregate independently of another pair during gametogenesis.

Question 44

WW and ww are the allelic combinations that are responsible for red and white flowers, respectively. What do WW, ww, and the flower colors represent?

Answer 44

WW and ww are the genotypes; red and white flowers are the phenotypes.

Question 45

When HH crosses with Hh, what is the probability of getting offspring with hh?

Answer 45

0%

Question 46

In a particular species of plant, orange flower petals are dominant over recessive white flower petals. What will be the genotype of the F1 generation if a homozygous dominant parent crosses with a homozygous recessive parent? (Note that P = dominant allele, and p = recessive allele)

Answer 46

All F1 generations will be heterozygous dominant.

Question 47

While studying a family tree, an observation made stated that all the male members of the family show the symptoms of hemophilia. If a hemophilic man (XhY) and a carrier female (XhX) sexually reproduce, what is the probability of the mother giving birth to a carrier-daughter and a non-carrier child? (Xh = mutant X-chromosome)

Answer 47

25% carrier-daughters and 25% non-carrier children

Question 48

One of the most common X-linked recessive disorders is color-blindness. A boy with color-blindness is born to a couple with normal vision. If NN and Nc represent the normal vision and color-blindness respectively, what would be the possible genotypes of the parents?

Answer 48

Father: NN; Mother: Nc