Genetics Review

Who is the “Father of Genetics”?

Gregor Mendel

What organism did Mendel use to study genetics?

Pea Plants

Transmission of characteristics from parents to offspring is called ___________________.

_____________ is the study of how characteristics are passed on from one generation to the next.

heredity

Genetics

__________________ = An allele that IS MASKED BY the presence of another allele

Recessive

The appearance of an organism is

its _____________phenotype

Another name for heterozygous

hybrid

The diagram at the rightis called a _____________Punnett square

__________________ = An allele that MASKS the presence of another allele

Dominant

A recessive gene is represented by a _________________ letter.lower case

_______________

are different gene

choices for a trait.

Alleles

A dominant gene is represented by a ____________ letter.(usually the first letter of the trait)

capital

When both alleles in the pair are the SAME the organism is ______________ Homozygous or purebred

When both alleles in the pair are DIFFERENT the organism is

_________________Heterozygous or hybrid

monohybridA cross that involves only 1 traitis called a ____________ cross.

Homozygous (HO) or Heterozygous (HE)?

TT ____Yy ____Hh ____Mm ____

Ee ____kk ____BB ____ ZZ ____

HO

HE

HE

HE HO

HO

HO

HE

Determine the Phenotype:

Pink flowers are dominant to red flowers

PP _____________Pp _____________pp _____________

Brown eyes are dominant to green eyes

BB ____________Bb ____________bb ____________

Pink

Pink

Red

Brown

Green

Brown

For each phenotype, list the genotype:

Straight hair is dominant to curly.

____________ straight____________ straight____________ curly

Square heads are dominant to round heads.

____________ square____________ square____________ round

SS

Ss

ss

SS

Ss

ss

In guinea pigs, black fur (B) is dominant over brown fur (b).

If a black Guinea pig is crossed witha brown Guinea pig and the littercontains a brown baby, the genotypeof the black parent is probably

BB Bb bb

Bb; Must have one B to be black must have one b to pass on to baby

T = Tall

t = short

The genotype of the offspring from the

cross at the right is _________.

Their phenotype is _________.

Tt

tall

The parents in this cross are _____________ Homozygous Heterozygous

Heterozygous

If G is dominant for green pods and g is recessive for yellow pods, what percentage of the offspring will have green pods? _______% 75

GG Gg

Gg gg

G gG

g

What are the possible phenotypes of their offspring?

(% and color)

Red throats (R) are dominant over white (r)throats in Goonie birds.

Make a cross between a PURE RECESSIVE and a HETEROZYGOUS Goonie bird.

50% red throats 50% white throats

Rr rr

Rr rr

R r

r

r

What are the possible phenotypes of their offspring?

(% and color)

Black eyes (B) are dominant over red eyes (b) in rats.

Make a cross between two HETEROZYGOUS rats.

75 % black eyes 25% red eyes

B b

B b

BB Bb

Bb bb

The parents in this cross are _____________ Homozygous Heterozygous

Homozygous

If W is dominant for long wings and w is recessive for short wings, what percentage of these offspring will have short wings? _______%

0% only ww makes it short

What is the probability the offspring will have straight tails?

In Reebops curly tails (T) are dominant over straight tails (t).

Make a cross between a HOMOZYGOUS DOMINANT and a HOMOZYGOUS RECESSIVE Reebop.

0% All will be Curly tailed (Tt)

Tt Tt

Tt Tt

T T

t

t

What will the offspring be like?

(% and color)

Purple (P)is the dominant color for monsters. Yellow is recessive (p).Make a cross between a HOMOZYGOUS purple and a yellow monster.

100% purple

Pp Pp

Pp Pp

P P

p

p