Exam #4 - Genetics Flashcards Preview

BSC 2010 - Biology I > Exam #4 - Genetics > Flashcards

Flashcards in Exam #4 - Genetics Deck (96)
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1

Is blending a correct model of inheritance?

No

2

Why did Gregor Mendel study pea plants?

1) Peas are eukaryotes
2) Cheap and easy to handle
3) Within a short amount of time, you can generate the next generation. Within a year or less

3

A character = ?

A characteristic

4

Flower color is a ________?
The plant height is a ________?
The pea color is a _________?
The pod shape is a __________?

Characteristic. These are all TRAITS

5

Variety is a TYPE of _________.

character

6

Red flowers....white flowers...tall height...small height...yellow peas...green peas...these are ________.

varieties. (Varieties are more SPECIFIC)

***Trait: Flower Color
***Variety: Red Flower (MORE SPECIFIC = VARIETY)

7

T/F: A pea plant can fertilize itself

True

8

In nature: self pollinate
Mendel: ____ _______

cross pollinate

9

Start with a parent that produces offspring just like itself...this is called _____ _______.

true breeding

10

Start with true breeding, but take two _______ true breeding varieties and _____ them. See what you get!

different, cross

11

This was Mendel's experiment:
Take a true breeding parent of one ______, and cross it with a true breeding individual of another ______. Same characteristic, but two different _______. And that will produce an offspring.

variety

12

Since this offspring is a parent of two varieties, it is known as a ______.

hybrid.
A hybrid generate by *cross pollination*

13

The hybrid is then allowed to ____ ________.
This last group of offspring is analyzed to see what conclusion we can draw.

self pollinate

14

The original generation is called _.
The hybrids are called __.
The final set of offspring is called __.

P
F1
F2

15

Mendel's experiment #1:
Crossed a true breeding individual with ______ seeds with a true breeding individual with _______ seeds.

round, wrinkled

16

What are the offspring? (F1)

All round

17

What were the results of the final offspring? (F2)

Round, wrinkled. 3:1 ratio
Wrinkled came back...

18

What conclusions did he draw from experiment #1?

1) His observations contradicted the blending model
2) Characters/traits are produced by 'heritable factors' that are DISCRETE

**Today we know that 'heritable factors' = genes

19

Experiment #1 conclusions:
1) Characters/traits are produced by 'heritable factors' that are DISCRETE
2) An organism has ___ genes for each trait.
-___ from each parent

Today we know:
We inherit a pair of ________ _________
-They have the _____ GENES!

two
one
homologous chromosomes
SAME

20

Why different phenotypes for a trait?

A gene has different "versions" or alleles (round, wrinkled)

21

Experiment #1 conclusions:
1) Characters/traits are produced by 'heritable factors' that are DISCRETE
2) An organism has TWO genes for each trait.
3) Genes have alternate versions called _______.

Today we know:
A gene can vary in its ________ ________.

alleles
nucleotide sequence

22

Based on mender's experiment...
Round seed phenotype: _________
Wrinkled seed phenotype: _________

DOMINANT
Recessive

23

Experiment #1 conclusions:
1) Characters/traits are produced by 'heritable factors' that are DISCRETE
2) An organism has TWO genes for each trait.
3) Genes have alternate versions called ALLELES
4) When different alleles are TOGETHER:
-Dominant allele: affects ________.
-Recessive allele: DOES NOT affect ________.

appearance

24

Experiment #1 conclusions:
1) Characters/traits are produced by 'heritable factors' that are DISCRETE
2) An organism has TWO genes for each trait.
3) Genes have alternate versions called ALLELES
4) Dominant allele: affects appearance
5) Alleles separate during gamete production.
-This is called ____ __ _________.

Today we know:
_______ __________ separate during meiosis I

Law of segregation
homologous chromosomes

25

Particulate Model of Inheritance:
'Genetic material' is composed of UNITS which are passed on to offspring, and which retain their ________.

IDENTITIES

26

Why 3:1 in F2?

USE A PUNNET SQUARE!

27

Punnet Square: predicts the result of a cross by accounting for _______ fertilization.

random

28

______ is the process of change in the genetic code.

mutation

29

Every allele today came about by _______.

mutations

30

_______ is the physical appearance of an organism.

phenotype