Genetics Vocabulary

Question 1

Genetics

Answer 1

The study of how traits are inherited and passed from one generation to another.

Question 2

Genes

Answer 2

A unit of heredity that can be passed down from a parent to their offspring.

Question 3

Self vs. Cross-pollination

Answer 3

Self=fertilizing one plant with its own pollen; cross=fertilizing one plant with a different plant’s pollen.

Question 4

Dominant vs. recessive

Answer 4

Dominant means that it only takes one inherited gene from one parent to show up. Recessive means that it needs to inherit both genes to be present.

Question 5

Homozygous/purebred

Answer 5

Two of the same genes being passed down through several generations to keep it the same. Ex: RR or rr.

Question 6

Heterozygous/hybrid

Answer 6

Inheriting both the dominant and nondominant gene. Ex: Rr.

Question 7

Allele

Answer 7

Alternate versions of a gene.

Question 8

Genotype

Answer 8

Genotype refers to your genetic makeup, or your combination of chromosomes. The three kinds are homozygous recessive (rr), homozygous dominant (RR), and heterozygous (Rr).

Question 9

Phenotype

Answer 9

The genetic traits/genes that are actually physically expressed by the offspring.

Question 10

Monohybrid cross

Answer 10

Crossing two versions of the SAME gene, one from each parent, such as crossing Rr and rr for tongue rolling.

Question 11

Dihybrid cross

Answer 11

Crossing two different traits from each parent, such as crossing CCRr and Ccrr for hair color and tongue rolling.

Question 12

Sex-linked traits

Answer 12

The gene is located on the sex chromosome.

Question 13

Pedigree

Answer 13

A chart that traces the inheritance of a genetic trait within a family.

Question 14

Polygenic trait

Answer 14

Two or more genes coding for a trait, like in eye color, hair color, IQ, and skin color.

Question 15

Multiple alleles

Answer 15

Three or more alleles per gene.

Question 16

Rh disease

Answer 16

When the father has positive blood, and the mother has negative blood, the baby’s blood could be positive. The mom’s body will make antibodies to the baby’s blood after birth, preventing her from having another baby.

Question 17

Rhogam

Answer 17

The medicine used to treat Rh disease.

Question 18

Sex-influenced trait

Answer 18

A gene that is found on the autosome, and its expression is influenced by sex hormones.

Question 19

Fraternal vs. identical twins

Answer 19

Fraternal twins are dizygotic, meaning that there were two eggs and two sperm, equalling two separate zygotes. Identical twins are monozygotic, meaning that the fertilized egg separates into two cells.

Question 20

Chromosome Map

Answer 20

A diagram that shows the location of a specific allele on a chromosome.

Question 21

Gene linkage

Answer 21

When two genes are so close together on a chromosome that they are almost always inherited together because they do not separate during crossing over. Ex: blond hair and blue eyes.

Question 22

Test cross

Answer 22

Crossing the parent with the unknown gene with the parent with the recessive gene and observing the offspring to figure out the genotypes.

Question 23

Codominance

Answer 23

Both genes are expressed equally and fully. Ex: crossing a white flower with a red one and getting offspring with spots of red and white.

Question 24

Incomplete dominance

Answer 24

When the offspring’s gene is an intermediate expression of both the parents’ genes, and neither is dominant. Ex; Crossing a red flower with a white one and getting a pink flower.

Question 25

Chromosomal deletion

Answer 25

The loss of DNA from a chromosome, often resulting in genetic defects.

Question 26

Chromosomal addition

Answer 26

Extra DNA is added to a chromosome.

Question 27

Chromosomal translocation

Answer 27

The movement of DNA from one chromosome to another, often when non-homologous chromosomes pair up for crossing over.

Question 28

Nondisjunction

Answer 28

Failure of chromosomes to separate properly during meiosis, leaving some cells with irregular numbers of chromosomes. (Ex: monosomy and trisomy.)

Question 29

Monosomy

Answer 29

A nondosjunction resulting in the offspring having only one gene of the pair. Ex: Turner’s syndrome.

Question 30

Trisomy

Answer 30

A nondisjunction resulting in the offspring having an extra chromosome. Ex: Down Syndrome

Question 31

Down’s Syndrome

Answer 31

AKA Trisomy 21, there are 3 copies of chromosome 21 instead of 2, leading to developmental and intellectual delays.

Question 32

Klienfelter’s Syndrome

Answer 32

When nondisjunction happens in the sex chromosomes, males can develop breasts and be infertile, although they are biologically male.

Question 33

Turner’s Syndrome

Answer 33

A monosomy due to nondisjunction in which a female is missing an X chromosome, and is therefore infertile.

Question 34

Karyotype

Answer 34

A picture of all of an individual’s chromosomes.

Question 35

Chorionic Villi testing

Answer 35

At 8-10 weeks pregnant, the doctor can use sonar and a flexible needle to remove fetal chorion cells. This can be dangerous, but it allows for karyotyping.

Question 36

Chorionic Villi testing

Answer 36

At 8-10 weeks pregnant, the doctor can use sonar and a flexible needle to remove fetal chorion cells. This can be dangerous, but it allows for karyotyping.

Question 37

Endoscopy/fetoscopy

Answer 37

It involves using a camera and an endoscope that is inserted directly into the organ. It can help detect hydrocephalus.