Genetics Study guide

Question 1

What is heterozygous? Also known as

Answer 1

Heterozygous is two different alleles for a trait also known as a carrier

Question 2

What is homozygous? Also known as?

Answer 2

Homozygous is 2 identical alleles for a trait, also known as true breeding.

Question 3

What is a recessive trait

Answer 3

an unexpressed trait in the alleles. It is a trait that is not as common, for example, blue or green eyes.

Question 4

What is a dominant trait?

Answer 4

a trait that is visibly expressed in the organism and are more likely to occur, for example, brown hair or brown eyes.

Question 5

What are the phenotypes and genotypes of blood

Answer 5

Phenotype A; Genotype AA or AO
Phenotype: B; Genotype BB or BO
Phenotype AB Genotype AB Phenotype O Genotype OO

Question 6

How many chromosomes are in a normal karyotype

Answer 6

46

Question 7

What is the result of mitosis

Answer 7

two new genetically identical daughter cells (46 chromosomes)

Question 8

Result of Meiosis

Answer 8

4 new different haploid cells being produced and it cuts the amount of chromosomes we have in half (from 46 to 23).

Question 9

Where are sex-linked genes located?

Answer 9

sex chromosomes

Question 10

Why do more men have sex linked disorders than women?

Answer 10

They only have one x chromosome while women have two so they can’t hide their recessive traits as well

Question 11

Which parent determines the sex of an offspring

Answer 11

males; contributed y chromosome

Question 12

What are the chromosomes for females and males

Answer 12

Females XX

Males XY

Question 13

What is a polygenic trait?

Answer 13

multiple genes that determine a trait (eye color)

Question 14

What is codominance

Answer 14

neither allele is recessive and the phenotypes of both alleles are expressed.

Question 15

What is incomplete dominance

Answer 15

when individuals show a blended phenotype

Question 16

What is independent assortment

Answer 16

Genes that segregate independently

Question 17

What characteristics are caused by multiple alleles

Answer 17

Blood groups

Question 18

what are autosomes

Answer 18

Any chromosomes that are not sex chromosomes

Question 19

What is nondisjunction? How does this affect the offspring

Answer 19

failure of homologous chromosomes to separate properly during meiosis; results in incorrect number of chromosomes in offspring (ex: one extra chromosome = trisomy, another complete set of chromosomes = polyploidy)

Question 20

Two phases of meiosis

Answer 20

The first phase is Prophase I, Metaphase I, Anaphase I, Telophase I and Cytokinesis.
The second phase is Prophase II, Metaphase II, Anaphase II, Telophase II and Cytokinesis.

Question 21

what happens in prophase 1

Answer 21

homologous pairs cross over (can only occur in this phase) and chromosomes condense (spindle forms) and nuclear envelope fragments

Question 22

what happens in metaphase 1

Answer 22

the homologous pairs align along the equator of the cell.

Question 23

what happens in anaphase 1

Answer 23

homologs separate and move to opposite poles. The sister chromatids remain attached to their centromeres

Question 24

What happens in telophase/cytokinesis

Answer 24

In Telophase I the nuclear envelope reassembles, the spindles disappear. In Cytokinesis the cells divide into

Question 25

what happens in prophase 2

Answer 25

chromosomes and spindles start to form.

Question 26

what happens in metaphase 2

Answer 26

the chromosomes meet in the middle again, however there is one straight line since the chromosomes are separated

Question 27

what happens in anaphase 2

Answer 27

chromatids are pulled away by the spindle fibers

Question 28

what happens in telophase II/ cytokinesis

Answer 28

Telophase II/ Cytokinesis the two cells divide again to result with 4 haploid cells.

Question 29

3 sources of genetic variation in sexual reproduction

Answer 29

independent assortment; gene shuffling; crossing over/genetic recombination

Question 30

What is epigenetics and how does it work

Answer 30

the study of how your behaviors and environment can cause changes that affect the way your genes work

Question 31

What factors influence your epigenome

Answer 31

Environmental and Lifestyle = nutrition, behavior, stress, physical activity, working habits, smoking/alcohol consumption

Question 32

What kinds of effects can epigenetics have

Answer 32

changes in how your body reads DNA