Bio test 4/17

What organism dia Mendel study?

Pea plants

What would be the possible genotypes of gametes in a pea plant that was heterozygous for both purple flowers and yellow peas?

Use sex-alleles

PY (dominant dominant)

Py (dominant recessive)

pY (recessive dominant)

py (recessive recessive)

What did Menda call a plant that when self-fertilized ALWAYS produced offspring with the same traits as itself?

pure purebred (homozygous)

Write all possible genotypes for a pea plant that is:

• tall

• white flowers

• green peas

1. TT ww yy

2. Tt ww yy

Self-pollinate a heterozveous tall purple flowered pea plant.

What is the probability of a tall white pea plant?

3/16

9:3:3:1

What is a gamete?

Sex cell

What is a test cross?

A cross with the homozygous recessive to find out the genotype of a dominant-traited organism.

What is the termn for each variation of a trait that is carried in the gamete?

Allele

What is the term for a trait that shows a phenotype in-between blended) the dominant / recessive phenotypes for a heterozygous individual?

Incomplete dominance

What is the term for a trait that is affected by more than one gene?

Polygenic trait

What shape is used to represent a male on a pedigree.

Square

Cross a heterozygous tall pea plant with a short pea plant.

What are the possible phenotypes (with ratios)

50% tall

50% short

What are the possible offspring genotypes with ratios) ifa heterozygous purple-flowered pea plant is self-fertilized?

25% homozygous dominant

50% heterozygous (dominant)

25% homozygous recessive

Black is dominant to brown coat.

Solid is dominant to spotted coat.

A brown/ spotted dog is crossed with a heterozygous dog. What are their genotypes (the parents)?

bbss x BbSs

Black is dominant to brown coat.

Solid is dominant to spotted coat.

A brown/ spotted dog is crossed with a heterozygous dog. What is the probability of having a puppy that is brown and spotted?

25%

S = short tail

s = long tail

B = brown

b= white

What are the possible Phenotypes (with ratios) of a cross between an all heterozygous cat and a heterozygous brown, long-tailed cat?

⅜ brown/ short tail

¾ brown/ Long tail

⅛ white/ short tail

⅛ White/ long tail

If a child has a genetic alsorder, but neither parent has that disorder, the disorder must be

Recessive

If a tongue roller dominant) and a non-tongue roller (recessive) mate, what is the HIGHEST percentage of non-tongue rollers in their offspring?

50%

What is the probability of having a cleft chin, widow's peak, dimpled child if both parents are heterozygous for all traits?

ALL TRAITS ARE DOMINANT

27/64

What are the parent's genotypes if their offspring have the following genotypic ratios?

¼ CCWw

¼ CcWw

¼ CCWW

¼ Ccww

CcWw x CCww

Are dominant traits always the more common trait in a population?

NO

How many total chromosomes are in a human gamete?

23

Long and brown hair in dogs) are both dominant to short and white.

What can you breed a long-brown haired dog with to find it's genotype?

Short/white haired dog

In humans, freckles (F) is dominant over no freckles (P, and brown eyes (B) is dominant over blue eyes b).

A man with freckles and brown eyes marries a woman with no freckles and brown eyes.

They have a child with no freckles and blue eyes. What was the probability of their child having these two traits together?

⅛ fbb

In horses, black coat color (B) is dominant over roan coat color (b), and a trotter T) is dominant over a pacer D.

A roan trotter mare was bred with a stallion to produce a roan pacer colt. Determine the genotypes of the colt and mare.

What are the possible genotypes for the stallion?

mare: bblt

colt: btt

stallion: BbTt, Bbtt, bbTt, bbtt

2 unaffected parent have an affected Child, the trait is

Recessive

2 affected parents have an Unaffected Child, the trait is?

Dominant

if 2 affected → affected is

LIKELY Recessive

What traits can skip generations

Recessive Traits

Incomplete Dominance: blending of the traits

blending of the traits.

Red flower + white flower = pink flower

Incomplete dominance:

Red flower + white flower = red and white petals

Independent Assortment:

1 allele from mom and one from dad

Autosomal Traits/ Disorders

Chromosomes 1-22

Expressed equally in Males & females.

Autosomal recessive:

only when both are recessive

*Cystic fibrosis, PKU, sichle Cell, aneria, and albinism

Autosomal dominant: horozygous condition is More severe than heters. Child wl 1 allesal parent 50% having it.

* Dwarfism, huntington's disease

horozygous condition is More severe than the heteros. Child with one affected parent 50% it.

* Dwarfism, huntington's disease

Parents create the

First generation

(They are NO F1)

Father of classical genetics

Mendel

What is a pedigree?How does a geneticist use pedigrees?

a chart that tracks which members of a family have a particular trait to trace the inheritance of traits over generations of families

Testcross:

Cross an organism with dominant phenotype but unknown genotype with a recessive phenotype

**their offspring will make it clear what the trait is