Chapter 8

Question 1

Genetics

Answer 1

The study of the transmission of traits (alleles) from one generation to the next (from parents to offspring)

Study of inheritance

Question 2

Gene

Answer 2

A sequence of DNA nucleotides that codes for a specific protein (feature of an organism )

There is at least one gene for every feature (characteristic)

Question 3

Allele

Answer 3

one of two or more versions of a gene that determines a particular trait for a characteristic

Question 4

Recessive

Answer 4

describes a trait whose expression is masked by another trait when the alleles for both traits are present in an individual

Question 5

Dominant

Answer 5

describes a trait that masks the expression of another trait when both versions of the gene are present in an individual

Question 6

Genotype

Answer 6

the underlying genetic makeup, consisting of both physically visible and non-expressed alleles, of an organism

Question 7

Phenotype

Answer 7

The observable traits or physical expression of genotype

The characteristic we see

Question 8

Heterozygous

Answer 8

having two different alleles for a given gene on the homologous chromosomes

Question 9

Homozygous

Answer 9

having two identical alleles for a given gene on the homologous chromosomes

Question 10

Assign genotypes using D and d

Homozygous dominant?
Homozygous recessive?
Heterozygous?

Answer 10

DD

dd

Dd

Question 11

Do all alleles for all genes exhibit a complete dominant/ recessive relationship?

Answer 11

No

Question 12

Codominance

Answer 12

Both alleles are equally and fully expressed in the heterozygous

complete and simultaneous expression of both alleles for the same characteristic

Question 13

Incomplete dominance

Answer 13

in a heterozygote, expression of two contrasting alleles such that the individual displays an intermediate phenotype

3 options

Question 14

Punnet square

Answer 14

a visual representation of a cross between two individuals in which the gametes of each individual are denoted along the top and side of a grid, respectively, and the possible zygotic genotypes are recombined at each box in the grid

Question 15

Genotypes for males and females with x-linked traits?

Answer 15

Red-Green Colorblind:
X^b X^b
X^b Y

Carrier:
X^B X^b

Normal:
X^B X^B
X^B Y

Question 16

How mitosis and meiosis fit into the human life cycle ?

Answer 16

Pass on genes and eggs, sperm that contain the instructions

Question 17

Gregor Mendel

Answer 17

Discover the fundamental laws of inheritance

Question 18

Which is better, dominant or recessive alleles?

Answer 18

Depends on the gene

A dominant gene is not necessarily better than recessive gene

Question 19

Among lethal alleles, which is rarer dominant or recessive alleles?

Answer 19

Dominant lethal alleles are rarer

Question 20

Múltiple alleles

Answer 20

More than two genes present on a chromosome

Question 21

Environmental factors

Answer 21

Traits can be affected by both genetic and environmental factors

Environment can alter the effects of genes

Question 22

Environmental factors examples?

Answer 22

Tanning and skin color

Nutrition and height

Exercise and physique

Experience and IQ tests

Question 23

Sex-linked genes

Answer 23

Genes located on the sex chromosomes

X-linked: located on the X, but not Y

Y-linked: located on the Y, but not X

Question 24

X-linked genes patterns pedigree

Answer 24

Males always inherit their X from their mother

Males more likely to express recessive X-linked traits than females

Only females can be carriers of X-linked recessive traits

Question 25

Autosomal pedigree

Answer 25

Two unaffected parents produce an affected child

Recessive trait skips a generation, producing completely unaffected individuals

Two affected parents only have affected children