Unit #3: Genetics and Meiosis

Question 1

Define genotype

Answer 1

the actual genetic makeup; letter are used to describe genes

Question 2

Define phenotype

Answer 2

observed physical characteristics (what the letters stand for)

Question 3

Define homozygous

Answer 3

organisms that have 2 identical alleles for a particular trait

Question 4

Define heterozygous

Answer 4

organisms that have 2 different alleles for the same trait

Question 5

Define segregation

Answer 5

the separation of alleles during gamete formation

Question 6

Define allele

Answer 6

the different forms of a single gene

Question 7

Define punnett square

Answer 7

used to show the different offspring between gametes

Question 8

Define homologous chromosomes

Answer 8

a pair of two chromosomes, one paternal and one maternal, that have the same genes in the same order, but there may be variation between them

Question 9

Define haploid (what type of cells are haploid)

Answer 9

cells that have only one set of chromosomes (23), sex cells (sperm +egg)

Question 10

Define diploid (what type of cells are diploid)

Answer 10

cells that have two sets of chromosomes (human somatic cells)

Question 11

Define tetrad

Answer 11

A four-part structure that forms during prophase I of meiosis and consists of two homologous chromosomes, each composed of two identical chromatids

Question 12

Define monozygotic twins (and their characteristics)

Answer 12

One egg, the egg divides in two, genetically identical, always the same sex, called identical twins

Question 13

Define dizygotic twins (and their characteristics)

Answer 13

Two eggs, the egg doesn’t divide, genetically unique, can be different sex, called fraternal twins

Question 14

What are the different types of triplets?

Answer 14

Monochorionic: all three offspring split from one egg
Dichorionic: two of the triplets split from the same egg, one is from a different egg (two are identical, one is fraternal)
Trychorionic: all 3 triplets come from a different egg

Question 15

In genetics, what does the word “dominant” mean?

Answer 15

Dominant refers to the relationship between two versions of one gene. The allele that will always show is called the dominant allele
It means it runs in families

Question 16

What is a karyotype?

Answer 16

An individual’s complete set of chromosomes, the term also refers to a laboratory-produced image of a person’s chromosomes isolated from an individual cell and arranged in numerical order

Question 17

How to determine the sex of a child through a karyotype

Answer 17

XX = female, Xy = male

Question 18

What is a pedigree? ( you will be given the pedigree symbols for the test)

Answer 18

The recorded ancestry, especially upper-class ancestry, of a person or family.

Question 19

Explain what maple syrup urine disease is

Answer 19

found in the Amish community, disorder in the branch chain amino acids, autosomal recessive: trait is found on the recessive allele

Question 20

What is meiosis?

Answer 20

The process of cell division in sex cells (gametes), reduction division, diploid - > haploid

Question 21

Meiosis I

Answer 21

prophase I, metaphase I, anaphase I, telophase I
End: two cells, homologous chromosomes have split

Question 22

Meiosis II

Answer 22

prophase II, metaphase II, anaphase II, telophase II
End: 4 cells, still haploid, split sister chromatids

Question 23

Prophase I

Answer 23

most important because tetrads form, where they exchange genetic information in a process called “crossing over”

Question 24

Mitosis vs. meiosis (Mitosis ver.)

Answer 24

Original parent cell is diploid, 2 daughter cells produced, daughter cells are diploid, daughter cells identical to parent cells, daughter cells are identical to each other, occurs in somatic cells

Question 25

Mitosis vs. meiosis (meiosis ver.)

Answer 25

Original parent cell is diploid, 4 sperm cells are produced (in males), one egg is formed (in females), daughter cells are haploid, daughter cells are not identical to parent cells, daughter cells are not identical to each other, occurs in sex cells

Question 26

How often does mitosis occur? How often does meiosis occur?

Answer 26

Depends on the cell, every 28 days (month) for females, every few hours for males

Question 27

How many viable sperm cells are created during meiosis? How many viable egg cells are created during meiosis?

Answer 27

4, 1 (3 polar bodies)

Question 28

What are polar bodies? How many polar bodies during female meiosis?

Answer 28

It is a small haploid cell produced at the same time as an egg cell, but does not have the ability to be fertilized, 3. Empty egg cells that cannot be fertilized

Question 29

What is gametogenesis?

Answer 29

The process in which cells undergo meiosis to form gametes. The formation of gametes

Question 30

What is oogenesis? Spermatogenesis?

Answer 30

Oogenesis: the production or development of female gametes. Formation of eggs
Spermatogenesis: the production of sperm. Formation of sperm

Question 31

Explain how the egg cell in a female and a sperm cell in the male develop prior to the child’s birth.

Answer 31

2 million primitive eggs stay in ovaries
Spermatogenesis: primitive sperm stay in testes
Starts out with 2 million eggs, by puberty it is around 400,000. A woman is born with all the eggs she’ll have and they will stay dormant until puberty. The egg only finishes meiosis when its fertilized (stops at metaphase II). Halts at prophase I for dormancy, once she hits puberty, meiosis continues until metaphase II.

Question 32

Explain what happens to the egg and sperm once the child reaches puberty.

Answer 32

Egg:
Before: start meiosis but stop at prophase l, 1 oocyte
Puberty: oocyte is released from ovary every 28 days, stop at metaphase ll
If fertilized: complete meiosis= zygote and 3 polar bodies
Sperm:
Before: start meiosis but stop at prophase l, 1 spermatocyte
Puberty: continues meiosis, 2 spermatocyte, 4 sperm made

Question 33

Who is considered the “Father of Genetics”? What type of plant did he study?

Answer 33

Gregor Mendel, pea plants

Question 34

How did Mendel set up his experiment, starting with the P1 generation to the F2 generation? (organize sentences into order)

Answer 34

Starts with P1 generation, if allowed to self breed, they are all pure bred. Took two p1 and cross pollinated them, one purple, and one white. F1 generation was all purple, “where did the white go?”, allowed F1 generation to self pollinate, the white came back ¼ of the time.

Question 35

What does “true-breeding” mean?

Answer 35

If self-pollinated, a plant would only produce offspring identical to themselves

Question 36

Summarize Mendel’s principles.

Answer 36

1: biological inheritance is determined by “factors” (genes) that are passed from one generation to the next
2: each trait was controlled by one gene that occurred in two contrasting forms called alleles
3: some of these factors are “dominant” while others are “recessive”
Offspring receive genes from their parents
Of those genes some are dominant some are recessive
Those traits come in contrasting traits called alleles

Question 37

List the steps to solving dihybrid story problems

Answer 37

Foil the parents
Fill out the chart (first parent goes on the side, second goes on top)
analyze!

Question 38

What are the 4 blood types?

Answer 38

AB, A, B, and O

Question 39

The type of antigen (protein) present

Answer 39

A: A but not B
B: B but not A
O: neither A or B
AB: A and B

Question 40

Possible genotypes

Answer 40

A: I^aI^a or I^ai
B: I^bI^b or I^bi
AB: I^aI^B
O: ii

Question 41

What type they can donate blood to

Answer 41

A: A, AB
A+: A+, AB+
A-: A+, A-, AB+, AB-
O: O, A, B, AB (all)
O+: O+, A+, B+, AB+
O-: everyone
B: B, AB
B+: B+, AB+
B-: B-, B+, AB-, AB+
AB: AB
AB+: AB+
AB-: AB+, AB-

Question 42

What type they can receive blood from

Answer 42

A: A, O
A+: A+, A-, O+, O-
A-: A-, O-
O: O
O+: O+, O-
O-: O-
B: B, O
B+: B+, B-, O+, O-
B-: B-, O-
AB: AB, A, B, O (all)
AB+: everyone
AB-: AB-, A-, B-, O-

Question 43

Antibodies found

Answer 43

A: b (has antibodies AGAINST b)
B: a (has antibodies AGAINST a)
AB: none (universal recipient)
O: a and b

Question 44

What is the rH factor? Why is it important during pregnancy?

Answer 44

It is an inherited protein, a 3rd antigen, found on the surface of red blood cells, if you have the protein you are positive (i.e AB+, A+, B+, O+). If you are negative for the protein and your baby is positive after the baby is born, your cells start to produce antibodies that attack the rH factor. So, if/when you have your next baby (that is also rH positive), your cells will start attacking the babys blood cells, leading to its death

Question 45

What blood type is the universal donor? Why? What blood type is the universal recipient? Why?

Answer 45

O- because it has no antigens, it is completely smooth and doesn’t cause a reaction with other blood cells. AB+, because it accepts A and B, all blood types accept O, and its positive meaning it can take blood from blood types with the rH factor and ones without. AB already has all the antigens so it has no antibodies

Question 46

What is the most common blood type? Least common?

Answer 46

O+, AB-

Question 47

Name two pros of CRISPR. Name two cons of CRISPR.

Answer 47

Pros: can be a possible cure for genetic diseases, can make crops climate resistant, and cheap
Cons: could be used for cosmetic use, can affect human evolution in future generations