19Ì¡qtl,
sEcÍ0N
6.4
TRAITS, GENES, AND ALLELES
Study Guide
KEY CONCEPT
Genes encode proteins that
produce a diverse range of
traits.
MAIN IDEA: The same
LARY
gene
heterozygous
phenotype
allele
gen0me
dominant
homozygous
genotype
recessive
,
gene can have many versions.
1. What is the relationship between a gene and a protein?
2.
What is an allele?
3.
What term describes a pair of alleles that are the same? that arc different?
4. Write a definition of homologous
chromosomes using the terms "gene" and "allele."
have
the same length, overall appearance, and genes, although the alleles may differ.
In the space below, draw a pair of homologous chromosomes. Label the chromosomes with
two sets of genes, one with homozygous alleles (Gene A, Gene A) and one with heterozygous
alleles (Gene B, Gene b).
c>
G
o
E
o
(J
in the textbook. Students will labol Gene A, Gene A, gene B,
.c
and Gene b.
lmages should be similar to the Visual Vocab on pg. 180
E
ç
o
L
o
r=
õ
F
'=
õÞ'
-o
ôo
@
c
õ)
À
Unit 3 Besource Book
McDougal Liltell Biology
Study
Guide 13
Name
Period
Date
STUDY GUIDE, CONTINUED
MAIN IDEA: Genes influence the development of traits.
5. Write an analogy to show the difference between genotype
and phenotype.
compared to someone's thoughts that you can't read.
6.
How are alleles represented on paper?
:.
7. Fill in the table below with the missing genotype, phenotype (dominant or recessive), or
alleles (TT, Tt, tt).
Phenotype
Alleles
dominant
homozygous dominant
homozygous recessive
TT
rec essive
tt
dominant
8. If an organism has a recessive
9.
trait, can you determine its genotype for that trait?
What factors besides alleles affect phenotype?
tc
a
o
Ë
o
O
c
E
Vocabulary Gheck
ç
o
1O. What type of alleles are present in an organism with a QQ genotype?
,"bqn9uygglrs4ofl¡n¡rìt ,,.
ll.
,,,,,
. --- -
-,, -;*".
E
CD
f
o
--
:É
o
E
J
What is an altemative form of a gene?
õol
l
allclp
o
ôo
12. What is the opposite of homozygous? of dominant?
o
r
.o)
o
()o
14
study Guide
Unit
3 Resource Book
It/cDougal
Liltell Biology