Bju Press - Science 7 - Chapter 7

Front 1

Units of heredity (how traits are passed off from parent to offpsring)

Back 1

genes

Front 2

The study of the inheritance of traits (passing from parents to offpsring)

Back 2

genetics

Front 3

Who researched pea plants to study heredity?

Back 3

Gregor Mendel

Front 4

An organism in which the traits have remained the same for many generations

Back 4

purebred

Front 5

Mating specific organisms to test how traits are inherited (such as Mendel mating tall pea plants with short ones)

Back 5

cross (cross breeding) - creates "hybrid" plants

Front 6

An organism whose parents are not alike (like the experiments with one tall pea plant and one short pea plant)

Back 6

hybrid

Front 7

How do you designate "first offspring generation"?

Back 7

F1

Front 8

How do you designate "second offspring generation"?

Back 8

F2

Front 9

When Mendel crossed a tall plant and a short plant, what did the F1 generation look like?

Back 9

All the plants were all.

Front 10

When Mendel allowed the F1 plants to pollinate themselves, what did the F2 plants look like?

Back 10

About 75% of the plants were all. About 25% were short.

Front 11

Describe one theory Mendel had about why the F2 plants were some short and some tall.

Back 11

He thought maybe each offspring had two factors - one from each parent.

Front 12

Describe another theory Mendel had about why the F2 plants were some short and some tall.

Back 12

Of the two factors that plant had, one was "dominate" and one was "recessive."

Front 13

Which trait has the most influence in an organism? dominate or recessive

Back 13

Dominate

Front 14

What happens if both traits the organism has are dominate?

Back 14

The plant has the dominate trait.

Front 15

What happens if both traits the organism are recessive?

Back 15

The plant has the recessive trait.

Front 16

What happens if one of the traits is dominate and the other is recessive?

Back 16

The organism shows the dominate trait; the factor for the recessive trait was hidden by the dominate factor.

Front 17

The way a plant or any organism looks - its physical characterics

Back 17

phenotype

Front 18

What forms when pollen and eggs unite

Back 18

zygotes

Front 19

The specific factors an organism posses

Back 19

genotype

Front 20

Where are genes (DNA segments) located?

Back 20

on chromosomes

Front 21

Where are chromosomes located?

Back 21

in the nucleus of the cell

Front 22

True or false: All chromosomes have the same number of genes.

Back 22

False: examples: humans have 46 chromosomes (or 23 pair); housefly has 12 (Note, however, that within the cells or any particular organism, the chromosome number is usually the same; i.e., all humans have 46)

Front 23

True or false: Chromosomes occur in pairs.

Back 23

True

Front 24

In the human, for example, there are 46 chromosomes. Where do these come from?

Back 24

23 come from the male; 23 come from the female. When the zygot is formed, it then has 46.

Front 25

What are Mendel's factors called today?

Back 25

genes

Front 26

What do the letters that are placed along the top and side of a punnett square represent?

Back 26

parents

Front 27

What is incomplete dominance?

Back 27

Two traits combine or blend together to produce a different trait. There is no pure dominant or pure recessive trait expressed. (red snapdraggon crossed with white snapdragon makes a pink snapdragon)

Front 28

What is codominance

Back 28

In this pattern, the dominant and the recessive traits are both expressed. (red cow crossed with a white cow make a "red and white" cow - that is, a roan)

Front 29

What does it mean when a trait is sex-linked?

Back 29

A sex-linked trait is an inherited trait that has a gene on the X chromosome, but no corresponding gene on the Y chromosome.

Front 30

People who have a gene for a trait but do not express the trait themselves

Back 30

carriers

Front 31

abnormal traits that are passed on through genes

Back 31

inherited disorders

Front 32

the study of heredity

Back 32

genetics

Front 33

an organism that is the offspring of parents with similar genetic makeups; usually the result of many generations of such breeding

Back 33

purebred

Front 34

the process of mating organisms to test how they inherit traits; the offspring produced by such a mating

Back 34

cross

Front 35

an offspring of two genetically unrelated individuals

Back 35

hybrid

Front 36

refers to the characteristic that is expressed, even when a recessive gene is present (expressed as TT or Tt - not tt)

Back 36

dominant

Front 37

refers to the characteristic that is masked when a dominant gene is present (the t in Tt)

Back 37

recessive

Front 38

The way an organism looks (its physical characterics)

Back 38

phenotype

Front 39

The specific factors (genes) an organism contains in its genetic makeup.

Back 39

genotype

Front 40

a cell formed by the union of two gametes

Back 40

zygote

Front 41

a cell that contains only one of each type of chromosome found in an organism; an egg or sperm

Back 41

gamete

Front 42

a type of inheritance in which the genes expressing a particular characteristic are neither domniant nor recessive; both genes influence the characteristic of an organism (red snapdragon and white snapdraggon make pink snapdragon)

Back 42

incomplete dominance

Front 43

a type of inheritance pattern where the dominant and recessive traits are both expressed (red cow and white cow make a "red and white" cow)

Back 43

codominance

Front 44

two or more gene pairs producing a single trait

Back 44

multiple gene inheritance

Front 45

the female chromosome

Back 45

X chromosome

Front 46

the mail sex chromosome

Back 46

Y chromosome

Front 47

What is a characteristic that has a gene of the X chromosome but no gene on the Y chromosome

Back 47

sex-linked trait

Front 48

an individual that possesses a gene for a specific trait, even if he does not exhibit that trait

Back 48

carrier

Front 49

an abnormal characteristic passed on through the genes

Back 49

inherited disorder