Genetics Exam Outline

Question 1

Genetics

Answer 1

Study of patterns in heredity and the variation of organisms.

Question 2

Heterozygous

Answer 2

A gene pair where two alleles don’t code for the same trait (different: Aa)

Question 3

Genotypes

Answer 3

Genetic makeup of an organism

Question 4

Sex Chromsomes

Answer 4

A chromosome that determines sex (gender.)

Question 5

Crossing Over

Answer 5

When 2 homologous chromosomes pair together and they cross each other. Some segments break off and reattach to the other chromosome.

Question 6

Somatic mutation

Answer 6

A mutation that takes place in an organisms body cells and can therefore affect the organism. (not passed to offspring)

Question 7

Universal Donor

Answer 7

Type O blood, anybody can receive it because it has no antigens (substance that stimulates as immune response.) Can only take type O blood.

Question 8

Gene

Answer 8

Segment of a chromosome that carries information about a trait.

Question 9

Homozygous

Answer 9

A gene pair where 2 alleles code for the same trait (same: dominant AA, recessive aa)

Question 10

Sex linked

Answer 10

Traits whose genes are carried on an x or y chromosome.

Question 11

Germ-cell Mutation

Answer 11

Mutations that occur in the gametes (sperm or egg cells.)

Question 12

Chromosome Mutation

Answer 12

Changes in the structure of a chromosome, or the loss of a entire chromosome.

Question 13

Universal acceptor

Answer 13

Type AB blood because it can accept A, B, AB, or O blood, can only give to other type AB’s.

Question 14

Alleles

Answer 14

The letters that show the genes from mom or dad. Alternate versions of a trait.

Question 15

Phenotype

Answer 15

External appearance of an organism that is determined by the individuals genotype.

Question 16

Autosomes

Answer 16

A chromosome that is not a sex chromosome.

Question 17

Linkage

Answer 17

The gens located on one chromosome form a linkage group. Because they are on the same chromosome they tend to be inherited together.

Question 18

Gene Mutation

Answer 18

occurs when a single nucleotide (which makes up DNA) is substituted, added, or removed.

Question 19

Pedigree

Answer 19

A diagram of the genetic history of an individual; can show how a trait is inherited over several generations.

Question 20

Mutation

Answer 20

A change in the DNA of an organism.

Question 21

Lethal Mutation

Answer 21

A mutation that causes death more often before birth. (ex: mutation that causes a miscarriage)

Question 22

Segregation

Answer 22

Pairs of gene variants are separated into reproductive cells.

Question 23

Independent Assortment

Answer 23

During meiosis, the random distribution of genes from different chromosomes to gametes.

Question 24

Linked

Answer 24

Two or more genes on the same chromosome.

Question 25

Karyotype

Answer 25

Photomicrographic of the chromosomes in a dividing cell found in a normal human.

Question 26

Huntington’s Disease

Answer 26

Gradual deterioration of brain tissue in middle age; shortened life expectancy.

Question 27

Hemophilia

Answer 27

When blood doesn’t clot properly, and if they get cut they will bleed uncontrollably.

Question 28

Cystic Fibrosis

Answer 28

Mucus clogs lungs; liver and pancreas; victims usually don’t live to adulthood.

Question 29

Dihybrid Cross

Answer 29

A cross of 2 pairs of genes

Question 30

Multiple Alleles (blood type cross)

Answer 30

Occurs in genes that have more then 2 alleles.

Question 31

Incomplete Dominance cross

Answer 31

Heterozygous individuals express both simultaneously with blending.

Question 32

How crossing over can affect the expected ratios

Answer 32

Crossing over causes the F2 generation to have many off spring with the recessive traits instead of lots with the dominant traits. this meant thee had to be some kid of change for this to have occurred. This could have been caused by a mutation but that only happens in a small percentage of offspring and this happened in a large amount. The alleles became rearranged so recessive traits became more common.