Bio Unit 5 Heredity

Question 1

What is heredity?

Answer 1

The passing of traits from parents to offspring.

Question 2

True or False: Alleles are different forms of a gene.

Answer 2

True

Question 3

What is the genotype?

Answer 3

The genetic makeup of an organism.

Question 4

What is the phenotype?

Answer 4

The physical expression of a genetic trait.

Question 5

Fill in the blank: The law of segregation states that alleles segregate during gamete formation.

Answer 5

alleles segregate during gamete formation.

Question 6

What is a dominant allele?

Answer 6

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

Question 7

What is a recessive allele?

Answer 7

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

Question 8

What does a Punnett square illustrate?

Answer 8

The possible genotypes of offspring from a genetic cross.

Question 9

True or False: A homozygous organism has two identical alleles for a trait.

Answer 9

True

Question 10

What is incomplete dominance?

Answer 10

A genetic situation where neither allele is completely dominant, resulting in a blended phenotype.

Question 11

Define codominance.

Answer 11

A genetic scenario where both alleles in a heterozygote are fully expressed.

Question 12

What is a dihybrid cross?

Answer 12

A genetic cross that examines two traits simultaneously.

Question 13

Fill in the blank: The locus is the physical location of a gene on a chromosome.

Answer 13

the physical location of a gene on a chromosome.

Question 14

What is a pedigree chart used for?

Answer 14

To track inheritance patterns of traits through generations.

Question 15

True or False: Sex-linked traits are often found on the Y chromosome.

Answer 15

False

Question 16

What is epistasis?

Answer 16

A genetic interaction where one gene masks or modifies the expression of another gene.

Question 17

What does the term ‘polygenic inheritance’ refer to?

Answer 17

Inheritance of traits that are controlled by multiple genes.

Question 18

What is a test cross?

Answer 18

A cross between an individual with an unknown genotype and a homozygous recessive individual.

Question 19

The independent assortment principle states that alleles for different traits segregate independently.

Answer 19

alleles for different traits segregate independently assortment

Question 20

What is a carrier in genetics?

Answer 20

An individual who has one copy of a recessive allele and does not express the trait.

Question 21

True or False: Genetic drift can lead to a change in allele frequencies in a population.

Answer 21

True

Question 22

Define gene linkage.

Answer 22

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

Question 23

What is the purpose of the Human Genome Project?

Answer 23

To map and understand all the genes of the human species.

Question 24

Genes vs Alleles vs trait

Answer 24

segments of DNA that encode proteins; A section of DNA that controls a trait.
Alleles a specific version of that gene.
Trait: A specific characteristic.

Question 25

What is a mutation?

Answer 25

A change in the DNA sequence that can lead to changes in phenotype.

Question 26

Meiosis:

Answer 26

The process of cell division that creates gametes.

Question 27

Crossing Over

Answer 27

A process during Meiosis where homologous chromosomes will pair up and exchange genetic information

Question 28

Homologous chromosomes vs Sister Chromatidds

Answer 28

Homologous Chromsomes: Same length, shape, size, but have different alleles. Sister Chromatids: Exact Duplicates.

Question 29

Random Fertilization

Answer 29

Random fertilization is the concept that each sperm and egg combination is unique due to independent assortment and crossing over during meiosis, leading to a vast number of potential genetic combinations in offspring. Any sperm can fertilize any egg.

Question 30

Total Number of unique cells

Answer 30

2^n n = chromosomes in a haploid cells.

Question 31

Nondisjunction

Answer 31

An error that occurs in meiosis that creates cells with too many or little chromosomes. This can happen if the chromosomes fail to separate properly. Meiosis I: n-1, n-1, n+1, n+1 Meiosis II: n, n, n-1, n+1 When this happens, the gametes produced often end in miscarriages or defects.

Question 32

Down Syndrome

Answer 32

Extra chromosome on chromosome 21

Question 33

Mendalls laws:

Answer 33

1: Law of Segregation - An individual has two alleles for a gene, but only one allele is passed down to each gamete. 2: Law of Independent Assortment - Genes for different traits assort independently during gamete formation; The inheritance of one gene does not affect the inheritance of another.

Question 34

Non-Nuclear Inheritance

Answer 34

Inheritance of material outside of the nucleus. Things such as mitochondria are only passed down from the mother.

Question 35

Phenotype Plasticity

Answer 35

The ability of an organism to change its phenotype based on environmental conditions, even tho its genotype stays the same.