11 notes

Question 1

Mendels 3 laws

Answer 1

1. Law of independent assortment
2. Law of segregation
3. Law of dominance

Question 2

4 ways beyond mono hybrid crosses that alleles / genes combine?

Answer 2

1. Incomplete dominance: red + white = pink
2. Codoninance: black + white = black/white
3. Multiple alleles:
4. Polygenic traits:

Question 3

Body cells are also…

Answer 3

Somatic and mitosis

Question 4

Sex cells

Answer 4

Gametes

Question 5

What other two words are used for crossing over

Answer 5

Synapsis and Recombination

Question 6

Different forms of a gene are called…

Answer 6

Alleles

Question 6

Different forms of a gene are called…

Answer 6

Alleles

Question 7

If a homozygous tall pea plant and a homozygous short pea plant are crossed…

Answer 7

No hybrids are produced.

Question 8

A Punnet square is used to determine the…

Answer 8

The probable outcome of the cross

Question 9

Organisms that have two identical alleles for a particular trait are said to be…

Answer 9

Homozygous

Question 10

The physical characteristics of an organism are is…

Answer 10

Phenotype

Question 11

A situation in which a gene has more than two alleles is known as

Answer 11

Polygenic dominance

Question 12

Unlike mitosis, meiosis results in the formation of…

Answer 12

Four haploid gamete cells

Question 13

To maintain the chromosome number of an organism, the gametes must…

Answer 13

Become diploid

Question 14

A gene map shows…

Answer 14

The relative locations of genes on a chromosome

Question 15

List the four basic principles of genetics that Mendel discovered with his experiments

Answer 15

The law of independent assortment (traits), law of segregation (separation), law of dominance (alleles), and law of probability.

Question 16

What is probability and how does it relate to genetics?

Answer 16

Probability is the likelihood that a particular event will occur and it can be used to predict the outcomes of genetic crosses.

Question 17

How do multiple alleles and polygenic traits differ?

Answer 17

Multiple alleles is a gene with more than two alternatives.

Polygenic traits is when more than one gene controls one trait.

Question 18

Why can multiple alleles provide many different phenotype so for a trait?

Answer 18

Multiple allies can provide many different phenotype so because there are more combinations of alleles causing more variations.

Question 19

Are an organisms characteristics determined only by its genes?

Answer 19

No because the environment can also affect its characteristics.

Question 20

Compare meiosis I with meiosis II in terms of the number and arrangement of chromosomes

Answer 20

Meiosis I: all the chromosomes are doubled and consist of duplicate chromosomes.
Meiosis II: the sister chromatids separate to produce four haploid daughter cells.

Question 21

Explain why it is chromosomes, not individual genes, that assort independently.

Answer 21

It is the chromosomes that are separated during meiosis. The genes are located on the chromosome.

Question 22

The scientific study of heredity is called ________

Answer 22

Genetics

Question 23

Describe Gregor Mendel’s peas

Answer 23

When pollen fertilizes an egg cell, a seed for a new plant is formed. Pea plants normally reproduce by self-pollination.

Question 24

What does it mean when pea plants are described as being true-breeding?

Answer 24

If they were allowed to self-pollinate they would produce offspring identical to themselves

Question 25

To preform his experiments, how did Mendel prevent pea flowers from self-pollinating and control their cross-pollination?

Answer 25

He joined male and female reproductive cells from two different plants.

Question 26

State the principle of dominance

Answer 26

That some alleles are dominant and others recessive

Question 27

What traits were controlled by dominant alleles in Mendel's pea plants?

Answer 27

Tall and yellow

Question 28

How did Mendel find out whether the recessive alleles were still present in F1 plants?

Answer 28

He crossed the F2 generation with itself to produce the F2 offspring.

Question 29

About one fourth of the F2 plants from Mendel's F1 crosses showed the trains controlled by the _________ allele

Answer 29

Recessive

Question 30

Mendel's explanation of the results from his F1 cross

Answer 30

Mendel assumed that a dominant allele has masked the corresponding recessive allele in the F1 generation. At some point, the allele for shortness was segregated, or separated, from the allele for tallness.

Question 31

What are gamets?

Answer 31

Specialized cells involved in sexual reproduction.

Question 32

What is the probability that a single coin will come up heads?

Answer 32

50% or 1/2

Question 33

Why can the principles of probability be used to predict the outcomes of genetic crosses?

Answer 33

The way in which alleles segregate is completely random.

Question 34

How do geneticists use Punnet squares?

Answer 34

They are used to predict and compare the genetic variations that will result from a cross.

Question 35

I'm Mendel's model of segregation, what was the ratio of tall plants to short plants in the F2 generation?

Answer 35

3:1

Question 36

The _____ the number of offspring from a genetic cross, the closer the resulting numbers will get to expected values

Answer 36

Larger

Question 37

How can you be sure of getting the expected 50:50 from flipping a coin?

Answer 37

You flip multiple times

Question 38

List the two things that Mendel's principles of genetics required in order to be true.

Answer 38

A. Each organism must inherit a single copy of every gene from both its "parents" B. When an organism produces its own gamets, those two sets of genes must be separated from each other so that each gamer contains just one set of genes.

Question 39

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

Answer 39

Each of the 4 chromosomes that came from the male parent has a corresponding chromosome from the female parent.

Question 40

Describe a diploid cell

Answer 40

2N | Contains two sets of homologous chromosomes

Question 41

The number of chromosomes in a haploid drosophila cell

Answer 41

4

Question 42

Why is meiosis described as a process of reduction division?

Answer 42

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

Question 43

What are the two distinct division of meiosis?

Answer 43

Meiosis I and Meiosis II

Question 44

How does a Tetrad form in prophase I of meiosis?

Answer 44

Each chromosome pairs with its corresponding homologous chromosome to from the structure called a Tetrad

Question 45

How many chromatids are in a Tetrad?

Answer 45

4

Question 46

What results from the process of crossing-over during prophase I?

Answer 46

It results in the exchange of alleles between homologous chromosomes and produces new combinations of alleles.