Study Guide Chapter 3

Question 0

What did Gregor Mendel do?

Answer 0

Mendel observed that traits often skip generations. Based on this observation, Mendel created an experiment to explain how that happens

Question 1

who is Gregor Mendel and what he is known for

Answer 1

He was a scientist who discovered the principles of heredity through his his study of pea plants. Because of his discoveries, he’s known as the father of genetics.

Question 2

What did Mendel do to prepare for his experiment

Answer 2

He let his pea plants self pollinate

Question 3

Why were pea plants a good choice?

Answer 3

Each characteristic of me had to possible traits. They produced a large number of offspring. Easy to collect large amounts of data to study. Grew quickly. The study can be completed faster.

Question 4

Mendel’s first experiment

Answer 4

Mendel cross- pollinated a purebred plant displaying one trait (tall) with a purebred plant displaying the other trait (short)
Genotype: TT x tt

Question 5

Mendel’s first experiment results

Answer 5

All the offspring were tall even though one of their parents was short

Question 6

Mendel’s second experiment

Answer 6

Mendel allowed the F1 generation to self pollinate
The offspring were a mixture of tall plants (dominant trait) and short plants (recessive trait) even though both parents(F1 generation) were tall

Question 7

Mendel’s second experiment results

Answer 7

Mendel got the same results in the F2 generation for each of the seven characteristics: a mixture of the dominant and recessive trait

Question 8

How did Mendel cross pollinate his plants

Answer 8

He did this by removing the female reproductive parts of one plant and the male reproductive part of the other plant and pollinating the plants by himself

Question 9

Mendel’s final conclusion

Answer 9

Mendel realized that his results could only be explained if each plant had two sets of instructions ( alleles) for each characteristic

Question 10

How do you know which trait is the dominant and which is recessive?

Answer 10

The dominant trait shows up more than the recessive trait

Question 11

Some of the other characteristics and traits Mendel studied

Answer 11

Flower color: purple, white
Seed color: yellow, green
Seed shape: round, wrinkled
Pod color: green, yellow
Flower position: along stem, at tip
Plant height: tall, short

Question 12

Why was Mendel’s work not recognized until he died

Answer 12

His results were overlooked and misunderstood at first

Question 13

Why do we use two letters to represent genotype

Answer 13

One for each allele

Question 14

Difference between dominant and recessive allele

Answer 14

The dominant allele masks or hides the recessive alleles. Displayed as a capital letter.
The recessive allele is displayed as a lowercase letter.

Question 15

Gene

Answer 15

The sets of instructions for inherited traits

Each parent gives one allele to its offspring creating a gene for a specific characteristic

Question 16

Phenotype

Answer 16

An organisms appearance

Question 17

Genotype

Answer 17

The genetic make up of an organism

The set of two alleles that gives the organism information about a particular characteristic

Question 18

Homozygous

Answer 18

An organism with two of the same alleles (letters) for a particular trait
Purebred

Question 19

Heterozygous

Answer 19

An organism with one dominant allele and one recessive allele for a particular trait
Hybrid

Question 20

Punnet square

Answer 20

A chart that is used to organize crosses

Question 21

Acquired trait

Answer 21

A characteristic that is the result of experience & influence of your environment

Question 22

Inherited trait

Answer 22

A characteristic that is genetically passed on from parents to offspring

Question 23

Codominance

Answer 23

Sometimes one trait is not completely dominant over another. Instead each allele has its own influence (neither trait is dominant or recessive)
The offsprings may be a new color or a mix of the parents colors

Question 24

Why is their only one possible genotype for an organism that shows the recessive trait

Answer 24

Because the recessive allele is always hidden by the dominant trait, except when the organism receives both recessive alleles from both parents

Question 25

Why are there two possible genotypes for an organism displaying the dominant trait

Answer 25

The dominant allele always masks the recessive allele.

There is a different genotype for a purebred and hybrid organism