Biology Chapter 11 Flashcards Preview

Biology Semester 2 > Biology Chapter 11 > Flashcards

Flashcards in Biology Chapter 11 Deck (41)
Loading flashcards...
0
Q

What happens when pollen fertilizes an egg cell?

A

A seed for a new plant is born

1
Q

What is genetics?

A

The scientific study of heredity

2
Q

What does the phrase true-breeding mean?

A

If a plant is allowed to self-pollinate, it will produce offspring identical to itself

3
Q

How did Mendel prevent plants from self-pollinating?

A

He cut away parts that produce pollen and dusted pollen from one plant to another

4
Q

What are specific characteristics that vary from one individual to another?

A

Traits

5
Q

What are genes?

A

Chemical factors that determine traits

6
Q

What are the offspring crosses between parents with different traits called?

A

Hybrids

7
Q

What are alleles?

A

The different forms of a gene

8
Q

What does the principle of dominance mean?

A

Some alleles are dominant while others are recessive

9
Q

True or false: In Mendel’s pea plants, tall and yellow were controlled by dominant alleles.

A

True

10
Q

About how many of Mendel’s F2 generation showed a recessive trait?

A

1/4

11
Q

What are gametes?

A

Sex cells that, when produced, cause a segregation of a dominant and recessive allele

12
Q

What is probability?

A

The likelihood that something will occur

13
Q

True or false: Alleles do not segregate randomly.

A

False

14
Q

How do geneticists use Punnett squares?

A

To predict and compare the genetic variations that will result from a cross

15
Q

What is the difference between genotype and phenotype?

A

Genotype is the genetic makeup of an organism while phenotype is the physical characteristics

16
Q

What does it mean when a plant is homozygous or heterozygous?

A

A homozygous plant have two identical alleles for a particular trait while a heterozygous plant has two different alleles for the same trait

17
Q

True or false: Homozygous organisms are true-breeding for a particular trait.

A

True

18
Q

What was the genotype for Mendel’s true-breeding round yellow peas?

A

RRYY

19
Q

True or false: Mendel observed that genes segregate independently in the F2 generation.

A

True

20
Q

What was Mendel’s principle of independent assortment?

A

Genes for different traits can segregate independently during the formation of gametes

21
Q

What happens in incomplete dominance?

A

One allele is not completely dominant over another

22
Q

What happens during codominance?

A

Both alleles contribute to the phenotype of the organism.

23
Q

What three criteria was Thomas Hunt Morgan looking for in a model organism for genetic studies?

A

Small
Easy to keep in a laboratory
Able to produce lots of offspring in little time

24
Q

What two factors determine an organism’s characteristics?

A

Genes

Interaction with the environment

25
Q

What does it mean when two sets of chromosomes are homologous?

A

Each chromosome from the female parent corresponds with the male parent

26
Q

What does 2N stand for?

A

A diploid cell

27
Q

Why is meiosis described as the process of reduction division?

A

The number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell

28
Q

What are the two distinct divisions of meiosis called?

A

Meiosis I and Meiosis II

29
Q

How many chromatids are in a tetrad?

A

4

30
Q

What results from the process of crossing-over?

A

The exchange of alleles between homologous chromosomes and produces new combinations of alleles

31
Q

What are the four phases of meiosis?

A

Prophase
Metaphase
Anaphase
Telophase

32
Q

True or false: Sperm and egg gametes are diploid cells.

A

False (haploid)

33
Q

What are polar bodies?

A

Cells produced in females that do not produce in reproduction

34
Q

True or false: Meiosis begins with a diploid cell and produces two genetically identical diploid cells.

A

True

35
Q

True or false: Thomas Hunt Morgan discovered that all genes follow the principle of independent assortment.

A

False

36
Q

What two conclusions did Morgan make about genes and chromosomes?

A

Each chromosome is actually a group of linked genes

Mendel’s principle of independent assortment still holds true

37
Q

What process sometimes separates linked genes?

A

Crossing-over

38
Q

True or false: Crossing over limits genetic diversity

A

False

39
Q

True or false: Genes that are closer are more likely to be separated by a crossover event in meiosis.

A

False

40
Q

What is a gene map?

A

A diagram that shows the relative location of each new gene