Biology Grade 11 - Unit 2

Front 1

heredity

Back 1

the passing of traits from parents to offspring

Front 2

genetics

Back 2

the branch of biology dealing with heredity and the variation of inherited characteristics

Front 3

DNA (deoxyribonucleic acid)

Back 3

a molecule that carries genetic information in cells

Front 4

gene

Back 4

a segment of a DNA molecule that codes for a particular trait; found at a specific location on a chromosome

Front 5

locus

Back 5

the location of a gene on a chromosome

Front 6

polyploid

Back 6

having more than two sets of chromosomes; ex. plants

Front 7

asexual reproduction

Back 7

the production of offspring from a single parent; the genetic makeup of the offspring is identical to that of the parent

Front 8

sexual reproduction

Back 8

the production of offspring by the fusion of two gametes

Front 9

fragmentation

Back 9

a method of asexual reproduction in which a piece or body fragment of the parent organism develops into a mature individual

Front 10

mitosis

Back 10

the process by which a eukaryotic cell divides the genetic material in its nucleus into two new identical nuclei

Front 11

interphase

Back 11

the longest phase of a cell's life that occurs between different periods of mitosis

Front 12

chromatin

Back 12

the tangled strands of DNA and protein within a eukaryotic nucleus

Front 13

sister chromatid

Back 13

the identical copy of a single chromosome that remains attached to the original chromosome of the centromere

Front 14

cytokinesis

Back 14

the process in which a eukaryotic cell divides its cytoplasm into two new daughter cells

Front 15

biotechnology

Back 15

the use and modification of organisms for applications in engineering, industry, and medicine

Front 16

genetically modified organism (GMO)

Back 16

an organism in which the genetic material has been altered using genetic engineering techniques

Front 17

gemete

Back 17

sex cells

Front 18

fertilization

Back 18

the formation of a zygote by the joining of two gametes

Front 19

zygote

Back 19

a cell produced by the fusion of two gametes

Front 20

ova

Back 20

female sex cells

Front 21

meiosis

Back 21

the two-stage cell division resulting in four daughter cells, each with half the amount of chromosomes as the parents cells

Front 22

homologous chromosomes

Back 22

matching pairs of chromosomes, similar in size and carrying information for the same genes

Front 23

tetrad

Back 23

a pair of homologous chromosomes (each with two sister chromatids)

Front 24

synapsis (occurs Prophase I)

Back 24

the physical pairing up of homologous chromosomes during prophase I of meiosis

Front 25

crossing over (Prophase I)

Back 25

the exchange of chromosome segments between homologous pairs during synapsis

Front 26

How many daughter cells are there at the end of Meiosis I and are they haploid or diploid?

Back 26

There are Two daughter cells at the end of Meiosis I and each is haploid

Front 27

How many daughter cells are there at the end of Meiosis II and are they haploid or diploid?

Back 27

There are Four daughter cells at the end of Meiosis II and each is haploid

Front 28

gametogenesis

Back 28

the production of gametes in animals

Front 29

spermatogenesis

Back 29

the production of mature sperm cells

Front 30

oogenesis

Back 30

the production of mature egg cells

Front 31

How many sperms cells are there at the end of spermatogenesis, and are they haploid or diploid?

Back 31

There are FOUR sperm cells at the end of spermatogenesis and all are haploid

Front 32

How many ova are there at the end of oogenesis and are they haploid or diploid?

Back 32

There is ONE ovum and THREE polar bodies at the end of oogenesis, and all are haploid

Front 33

karyotype

Back 33

the chromosomes of an individual that have been sorted and arranged according to size and type

Front 34

sex chromosomes

Back 34

chromosomes that differ in males and females of the same species; the combination of sex chromosomes determines the sex of the offspring

Front 35

autosomes

Back 35

non-sex chromosomes

Front 36

non-disjunction

Back 36

the failure of homologous chromosomes to move to opposite poles of the cell during meiosis

Front 37

trisomy

Back 37

a chromosomal abnormality in which there are three homologous chromosomes in place of a homologous pair

Front 38

monosomy

Back 38

a chromosomal abnormality in which there is a single chromosome in place of a pair

Front 39

Where does down syndrome occur in the karyotype?

Back 39

It's a trisomy 21 (three homologous chromosomes on the the chromosome number 21)

Front 40

maternal inheritance

Back 40

a type of inheritance in which a zygote formed from two gametes inherits cytoplasmic DNA from only the female gamete

Front 41

paternal inheritance

Back 41

a type of inheritance in which a zygote formed from two gametes inherits cytoplasmic DNA from only the male gamete

Front 42

trait

Back 42

a particular version of a characteristic that is inherited, such as hair color or blood type

Front 43

true-breeding organism

Back 43

an organism that produces offspring that are genetically identical for one or more traits when self-pollinated or when crossed with another true-breeding organism for the same traits

Front 44

hybrid

Back 44

the offspring of two different true-breeding plants

Front 45

cross

Back 45

the successful mating of two organisms from distinct genetic lines

Front 46

P generation

Back 46

the parent organisms used in a cross

Front 47

F1 Generation

Back 47

the offspring of P-generation cross

Front 48

monohybrid

Back 48

the offspring of two different true-breeding organisms that differ in only one characteristic

Front 49

monohybrid cross

Back 49

a cross designed to study the inheritance of only one trait

Front 50

F2 generation

Back 50

offspring of an F1-generation cross

Front 51

allele

Back 51

a specific form of a gene

Front 52

homozygous

Back 52

describes an individual that carries two of the same alleles for a given characteristic

Front 53

heterozygous

Back 53

describes an individual that carries two different alleles for a given characteristic

Front 54

genotype

Back 54

the genetic makeup of an individual

Front 55

phenotype

Back 55

an individual's outward appearance with respect to a specific characteristic

Front 56

dominant allele

Back 56

the allele that, if present, is always expressed

Front 57

recessive allele

Back 57

the allele that is expressed only if it is not in the presence of the dominant allele (heterozygous for the recessive allele)

Front 58

test cross

Back 58

a cross used to determine the genotype of an individual expressing a dominant trait

Front 59

complete dominance

Back 59

a situation where an allele will determine the phenotype, regardless of the presence of another allele

Front 60

incomplete dominance

Back 60

a situation where neither allele dominates the other and both have an influence on the individual; results in partial expression of both traits (ex. mixing a red and white rose will get a pink rose)

Front 61

codominance

Back 61

a situation where both alleles are expressed fully to produce offspring with a third phenotype (ex. mixing a red bull and white cow gets a roan calf)

Front 62

pedigree

Back 62

a diagram of an individual's ancestors used in human genetics to analyze the Mendelian inheritance of a certain trait (also used in breeding)

Front 63

autosomal inheritance

Back 63

inheritance of alleles located on autosomal (non-sex) chromosomes

Front 64

sex-linked

Back 64

describes an allele that is found on one of the sex chromosomes, X or Y, and when passed on to offspring is expressed

Front 65

X-linked

Back 65

phenotypic expression of an allele that is found on the X chromosome (we only studied this) --> ex. red-green color blindness, male pattern baldness, and Hemophilia A

Front 66

mutation

Back 66

a change in the genetic code of an allele; the change may have a positive effect, a negative effect, or no effect

Front 67

carrier testing

Back 67

a genetic test that determines whether an individual is heterozygous for a given gene that results in a genetic disorder

Front 68

genetic screening

Back 68

tests used to identify the presence of a defective allele that leads to a genetic disorder

Front 69

dihybrid cross

Back 69

a cross that involves two genes, each consisting of heterozygous alleles

Front 70

law of independent assortment

Back 70

if genes are located on separate chromosomes, they will be inherited independently of one another

Front 71

product law

Back 71

the probability of two independent random events both occurring is the product of the individual probabilities of the events

Front 72

discontinuous variation

Back 72

when the expression of the products of one gene has no bearing on the expression of the products of a second gene

Front 73

continuous variation

Back 73

when the product of one gene is affected by the product of another gene, the gene products may be additive, or one product may negate another product

Front 74

additive allele

Back 74

an allele that has a partial influence on a phenotype

Front 75

nuclein

Back 75

the original name given to DNA when it was discovered by Friedrich Miescher in 1869

Front 76

nucleotide

Back 76

the repeating unit in DNA; it comprises of deoxyribose sugar, a phosphate group, and one of the four nitrogenous bases

Front 77

x-ray crystallography

Back 77

a technique in which a pure substance is subjected to x-rays; the pattern in which the x-rays bend and spread helps reveal the structure of the pure substance

Front 78

scientific model

Back 78

a simplified representation of a concept; can be tangible or conceptual

Front 79

complementary base pairing

Back 79

pairing of the nitrogenous base of one strand of DNA with the nitrogenous base of another stand; adenine (A) pairs with thymine (T), and guanine (G) pairs with Cytosine (C).

Front 80

point mutation

Back 80

a small-scale change in the nitrogenous base sequence of a DNA; the mutation may be beneficial, harmful, or neutral

Front 81

chromosome mutation

Back 81

an error that involves an entire chromosome or a large part of a chromosome

Front 82

spontaneous mutation

Back 82

a mutation that is not caused by any outside factors; it occurs randomly

Front 83

induced mutation

Back 83

a mutation that occurs because of exposure to an outside factor; second-hand smoke increases the chance of developing lung cancer

Front 84

antibiotic resistant

Back 84

describes strains of bacteria that are no longer susceptible to the effects of antibiotics; are sometimes called "superbugs" and are prevalent in hospital settings

Front 85

transposon

Back 85

a specific segment of DNA that can move along or between the chromosomes

Front 86

transposition

Back 86

the process of moving a gene sequence from one part of the chromosome to another part of the chromosome

Front 87

human genome

Back 87

the sequence of DNA nitrogenous bases found on the 23 sets of chromosomes in humans

Front 88

coding DNA

Back 88

a region of DNA that contains a sequence of nucleotides that will be expressed; a gene

Front 89

non-coding DNA

Back 89

a region of DNA that does not contain a sequence of nucleotides that will be expressed

Front 90

functional genomics

Back 90

the study of the relationship between genes and their function

Front 91

model organism

Back 91

an organism that can be used to study biological functions of another organism, due to its genetic similarity

Front 92

DNA bank

Back 92

a database of DNA sequences; the sequences can be from plants, animals, or humans

Front 93

DNA fingerprinting

Back 93

a pattern of bands on a gel that is unique to each individual

Front 94

restriction enzyme

Back 94

a molecule that has the ability to cut DNA at a specific site; different restriction enzymes recognize and cut different sites

Front 95

recombinant DNA

Back 95

a fragment of DNA consisting of nucleotide sequences from at least two different sources

Front 96

gene therapy

Back 96

the process by which defective genes in a genome are corrected with a normal copy of the gene

Front 97

target cell

Back 97

one of the cells that contain the faulty gene to be corrected