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Flashcards in Chapter 3 Deck (28):
1

Trait

physical characteristics

2

heredity

the passing of traits from parents to offspring

3

genes

the factors that controls traits

4

alleles

different forms of genes

5

dominate alleles

one whose trait always shows up in the organism when the allele is present

6

recessive alleles

an allele that is masked or covered up

7

probability

the likelihood that a particular event will occur

8

punnett square

a chart that shows all the possible combinations of alleles that can result from a genetic cross

9

phenotype

physical appearance or visible trait

10

genotype

genetic makeup or allele combination

11

homozygous

an organism that has two identical alleles for the trait

12

heterozygous

an organism that has two different alleles for a trait

13

codominance

the alleles are neither dominant nor recessive

14

messenger RNA

copies the coded message from the DNA in the nucleus, and carries the message into the cytoplasm

15

transfer RNA

carries amino acids and adds them to the growing protein

16

What did Gregor Mendel experiment with to understand heredity?

pea plants

17

What type of letter represents a dominant allele?

capital

18

What type of letter represents a recessive allele?

lower case

19

On what are genes carried from their parents to their offsprings?

chromosomes

20

Human body cells contain how many pairs of chromosomes?

23

21

Human body cells contain how many individual chromosomes?

46

22

Are pairs of chromosome genes lined up in the SAME or OPPOSITE order from one end of the chromosome to the other?

Same

23

A DNA molecule is made up of four nitrogen bases. What are they?

thymine
adenine
guanine
cytosine

24

You are going to cross two tall pea plants (Tt). Use the Punnett Square to show this cross.

TT|Tt
Tt|tt

25

True or False
Genes are factors that control traits.

True

26

True or False
Recessive alleles mask dominant alleles.

False

27

True or False
Dominant alleles always show up in the organism when present.

True

28

True or False
Alleles are different forms of a gene.

True