Unit 5 Vocab - Heredity

Question 1

Meiosis

Answer 1

a type of cell division in sexually reproducing organisms that reduces the number of chromosomes in gametes (the sex cells, or egg and sperm)

Question 2

Somatic cells (autosomes)

Answer 2

the cells in the body other than sperm and egg cells

Question 3

Alleles

Answer 3

matching genes; one from our biological mother, one from our biological father

Question 4

Gametes

Answer 4

a reproductive cell of an animal or plant

Question 5

Haploid

Answer 5

the presence of a single set of chromosomes in an organism’s cells.

Question 6

Nondisjunction

Answer 6

the failure of the chromosomes to separate, which produces daughter cells with abnormal numbers of chromosomes

Question 7

Diploid

Answer 7

the presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair

Question 8

Germ cell

Answer 8

a progenitor cell that culminates in a gamete, or the sexual reproductive cell at any stage from the primordial cell to the mature gamete

Question 9

Crossing-over

Answer 9

the exchange of DNA between paired homologous chromosomes (one from each parent) that occurs during the development of egg and sperm cells (meiosis)

Question 10

Polar body

Answer 10

a cell that separates from the immature ovum during meiosis and that contains a nucleus produced in the first or second division of meiosis but very little cytoplasm

Question 11

Genotype

Answer 11

the genetic makeup of an organism

Question 12

Phenotype

Answer 12

an individual’s observable traits

Question 13

Sexual Reproduction

Answer 13

Each parent contributes a gamete - a sex cell that has half of the normal DNA of a regular body cell

Question 14

Homologous chromosomes

Answer 14

one of a pair of chromosomes with the same gene sequence, loci, chromosomal length, and centromere location

Question 15

Karyotype

Answer 15

an individual’s complete set of chromosomes.

Question 16

Recombination

Answer 16

the process by which DNA strands are broken and repaired, producing new combinations of alleles

Question 17

Zygote

Answer 17

fertilized egg cell that results from the union of a female gamete (egg, or ovum) with a male gamete (sperm)

Question 18

Dominant allele

Answer 18

produces a dominant phenotype in individuals who have one copy of the allele, which can come from just one parent.

Question 19

Recessive allele

Answer 19

A type of allele that when present on its own will not affect the individual.

Question 20

Monohybrid cross

Answer 20

a breeding experiment in which the parents differ in only one genetically determined trait.

Question 21

Dihybrid cross

Answer 21

a mating experiment between two organisms that are identically hybrid for two traits.

Question 22

Law of segregation

Answer 22

only one of the two gene copies present in an organism is distributed to each gamete (egg or sperm cell) that it makes, and the allocation of the gene copies is random.

Question 23

Homozygous

Answer 23

having inherited the same versions (alleles) of a genomic marker from each biological parent

Question 24

Heterozygous

Answer 24

having inherited different versions (alleles) of a genomic marker from each biological parent

Question 25

Probability

Answer 25

a measure of the likelihood of a statement or a theoretical expectation is correct

Question 26

Incomplete Dominance

Answer 26

a form of Gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype

Question 27

Codominance

Answer 27

a type of inheritance in which two versions (alleles) of the same gene are expressed separately to yield different traits in an individual

Question 28

Law of Independence Assortment

Answer 28

genes do not influence each other with regard to the sorting of alleles into gametes

Question 29

Pedigree

Answer 29

a genetic representation of a family tree that diagrams the inheritance of a trait or disease though several generations.

Question 30

Epistasis

Answer 30

a phenomenon in genetics in which the effect of a gene mutation is dependent on the presence or absence of mutations in one or more other genes,

Question 31

Sex-linked Genes

Answer 31

characteristics (or traits) that are influenced by genes carried on the sex chromosomes

Question 32

Linked genes

Answer 32

genes carried on the same chromosome

Question 33

Test cross

Answer 33

a way to explore the genotpye of an organism.

Question 34

Multiple allele inheritance

Answer 34

When there is a gene existing in more than two allelic forms

Question 35

Pleiotropy

Answer 35

the phenomenon in which a single locus affects two or more apparently unrelated phenotypic traits

Question 36

Chromosomal Inheritance

Answer 36

genes are found at specific locations on chromosomes,

Question 37

Barr Body

Answer 37

the inactive X-chromosome in the somatic cells of mammalian females

Question 38

Deletion

Answer 38

changes the DNA sequence by removing at least one nucleotide in a gene.

Question 39

Dupiication

Answer 39

a type of mutation in which one or more copies of a DNA segment (which can be as small as a few bases or as large as a major chromosomal region) is produced

Question 40

Translocation

Answer 40

occurs when a chromosome breaks and the (typically two) fragmented pieces re-attach to different chromosomes