Intro Genetics

We all have two alleles, or versions, of each gene. Being ​ (a)   for a particular gene means you inherited two identical versions. It's the opposite of a ​ (b)   genotype, where the alleles are different. People who have recessive traits, like blue eyes or red hair, are always homozygous for that gene.

• homozygous
• heterozygous

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

​ (a)   are always expressed when the connected allele is dominant, even if only one copy of the dominant trait exists. ​ (b)   are expressed only if both the connected alleles are recessive.

• Dominant traits
• Recessive traits

Tags

NGSS.HS-LS3-1

Which of the choices is homozygous dominant?

• BB

• Bb

• bb

Two heterozygous (Tt) tall pea plants are crossed. Which describes their offspring?

• 50% tall and 50% short
• 75%tall and 25% short
• 100%short

G = green, g = yellow
The genotype for a yellow plant is...

• GG
• Gg
• gg
• all of the choices result in yellow

What type of inheritance do two alleles have if their traits blend together? 

• Incomplete Dominance
• Co-Dominance
• Mendelian Inheritance
• Homozygous Inheritance

A calico cat shows both the traits for orange fur and black fur. What kind of allele expression is this?

• Incomplete Dominance
• Co dominance
• Independent assortment
• Recessive inheritance

A red flowered plant (RR) breeds with a White flowered plant (WW). The gene for petal color in these plants expresses incomplete dominance.  What percentage of the offspring will have pink (RW) flowers?

• 0%
• 25%
• 50%
• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Codominance occurs in calico cats, which allows for the Black and Tan colors to show. What percentage of the offspring represented in this P square will be calico (black and tan spotted)?

• 25%

• 50%

• 75%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

What is a gene?

• An entire chromosome that  codes for a trait
• a piece of clothing
• a piece of a DNA on chromosome that codes for a trait
• Chemical messengers in your brain that code for a trait