Exam 1

Question 1

science

Answer 1

a way of knowing - an approach to understanding the natural world

Question 2

inquiry

Answer 2

at the heart of science; a search for information and explanations of natural phenomena

Question 3

data

Answer 3

recorded observations; items of information on which scientific inquiry is based

Question 4

inductive reasoning

Answer 4

makes broad generalizations from specific observations
ex: the generalization “all organisms are made of cells” was based on two centuries of microscopic observations made by biologists examining cells in diverse biological specimens

Question 5

deductive reasoning

Answer 5

from general premises, we extrapolate to the specific results we should expect if the premises are true
ex: in the scientific process, deductions usually take the form of predictions of results that will be found if a particular hypothesis is correct

Question 6

hypothesis

Answer 6

an explanation, based on observations and assumptions that leads to a testable prediction

Question 7

experiment

Answer 7

a scientific test, often carried out under controlled conditions

Question 8

independent variable

Answer 8

changed by scientist, manipulated variable

Question 9

dependent variable

Answer 9

measured by scientist

Question 10

control variable

Answer 10

unmanipulated group, constants

Question 11

character

Answer 11

a heritable feature that varies among individuals; ex flower color

Question 12

trait

Answer 12

each variant for a character; ex purple flowers or white flowers

Question 13

true-breeding

Answer 13

kind of breeding wherein the parents would produce offspring that would carry the same phenotype, parents are homozygous for every trait

Question 14

hybridization

Answer 14

the crossing of two true-breeding varieties

Question 15

parental generation (P generation)

Answer 15

refers to the first set of parents crossed

Question 16

first filial generation (F1 generation)

Answer 16

offspring of the P generation

Question 17

second filial generation (F2 generation)

Answer 17

offspring of the F1 generation

Question 18

alleles

Answer 18

are one or two or more alternative forms of a gene; ex P is the purple allele and p is the white allele

Question 19

dominant allele

Answer 19

determines organisms appearance, usually represented by a capital letter

Question 20

recessive allele

Answer 20

type of allele which will not be expressed in an individual unless both of the individual’s copies of that gene have that particular genotype

Question 21

Law of segregation

Answer 21

states that the two alleles for a heritable character segregate (separate from each other) during gamete formation and end up in different gametes

Question 22

Punnett square

Answer 22

diagrammatic device for predicting allele composition of all offspring resulting from a cross between individuals of known genetic makeup

Question 23

homozygote

Answer 23

an organism that has a pair of identical alleles for a gene encoding a character

Question 24

homozygous

Answer 24

when an organism has identical alleles, they are homozygous for that gene

Question 25

heterozygote

Answer 25

an organism that has two different alleles for a gene encoding a character

Question 26

heterozygous

Answer 26

when an organism has two different alleles, they are heterozygous for that character

Question 27

genotype

Answer 27

genetic makeup; ex Bb

Question 28

phenotype

Answer 28

organism's appearance or observable traits; ex flower color

Question 29

testcross

Answer 29

using a punnett square to test a cross between an organism of unknown genotype with a recessive homozygote

Question 30

monohybrid

Answer 30

an organism that is heterozygous for the single character being followed

Question 31

monohybrid cross

Answer 31

a cross between two organisms with different variations at one genetic locus of interest

Question 32

dihybrid

Answer 32

an organism that is heterozygous for the two characters that are being followed

Question 33

dihybrid cross

Answer 33

a cross between two individuals who differ in two observed traits that are controlled by two distinct genes

Question 34

Law of independent assortment

Answer 34

states that two or more genes assort independently - that is, each pair of alleles segregates independently of any pair during gamete formation; applies only to genes (allele pairs) located on different chromosomes or very far away on the same chromosome

Question 35

pedigree

Answer 35

family tree describing the traits of parents and children across the generations

Question 36

carriers

Answer 36

organisms who are phenotypically normal, but have the recessive allele for a trait and may transmit it to their offspring

Question 37

sex-linked gene

Answer 37

a gene located on either sex chromosome

Question 38

X-linked gene

Answer 38

genes on the X chromosome

Question 39

zygote

Answer 39

fertilized egg cell, diploid cell

Question 40

Drosophila

Answer 40

fruit fly

Question 41

hemizygous

Answer 41

describes an individual who only has one member of a chromosome pair, often used to describe X-linked genes in males who only have one X chromosome

Question 42

multiplication rule

Answer 42

states that to determine probability, multiply the probability of one event by the probability of the other event

Question 43

addition rule

Answer 43

states that the probability that any one of two or more mutually exclusive events will occur is calculated by adding their individual probabilities

Question 44

complete dominance

Answer 44

when a dominant allele takes complete control, meaning that the phenotypes of a heterozygote and a homozygote are indistinguishable

Question 45

incomplete dominance

Answer 45

when neither allele is completely dominant and heterozygotes have a phenotype that is a mix of the two parental varieties

Question 46

codominance

Answer 46

when the two alleles are both dominant and heterozygotes exhibit both phenotypes

Question 47

Tay-Sachs disease

Answer 47

affects children, only homozygotes can have the disease and is codominant

Question 48

pleiotropy

Answer 48

where one gene affects multiple traits | ex: sickle cell disease, flower color gene also determines seed coat color

Question 49

epistasis

Answer 49

where one gene influences another gene ex: coat color in labradors, where the gene for pigment (E) can influence whether or not the gene for coat color (B) is represented or not.

Question 50

quantitative characters

Answer 50

vary in the population in gradients along a continuum

Question 51

polygenetic inheritance

Answer 51

where many genes influence a single trait | ex: human height is controlled by around 180 genes