Unit C - Cloning, abnormal cell division, and cell growth

Question 1

What is Cloning?

Answer 1

The process in which identical offspring are formed from a single cell or tissue.

Question 2

Does sexual or asexual reproduction create cloning?

Answer 2

Asexual

Question 3

What is the blastula stage?

Answer 3

when the fertilized cell is a blastocyst.

Question 4

Why can’t you clone an animal in the gastrula (gastrulation) phase?

Answer 4

because the germ layers & most other cells are already differentiated.

Question 5

What are the 3 steps of cloning?

Answer 5

1. Removal of the nucleus of an unfertilized egg
2. extract a nucleus of a cell in the blastula stage
3. Transplant the Totipotent nuculus

Question 6

Define Totipotent.

Answer 6

a nucleus that is able to brng a cell from an egg to adult

Question 7

When are cells in mammals totipotent?

Answer 7

before the 8 cell stage of cleavage.

Question 8

What is the definition of monozygotic?

Answer 8

developed from a single fertilized cell, as identical twins.

Question 9

What is the definition of dizygotic?

Answer 9

developed from two fertilized cells, as fraternal twins.

Question 10

Are dizygotic cells twins?

Answer 10

No, they have different DNA

Question 11

Which cells escape the aging process and the biological clock?

Answer 11

Spermatocytes and cancerous cells.

Question 12

What are the three theories of cell aging/cell death?

Answer 12

1. Aging is caused by mutations
2. Aging genes shut down chemical reactions within the body
3. Aging occurs when cell lineages die out (telomeres)

Question 13

What are Telomeres?

Answer 13

Ends of chromosomes that shorten during DNA replication

Shortening Telomeres is a potencial theory to cell aging.

Question 14

What is the definition of cancer?

Answer 14

A broad group of diseases characterized by the rapid, uncontrolled growth of cells → forms a mass & shortens interphase.

Question 15

What is the difference between the cells formed from Meiosis compared to mitosis?

Answer 15

During meiosis, the amount of chromosomes each cell has is halved (haploid cells)

Question 16

What does sexual reproduction help with in diversification?

Answer 16

It helps ensure a recombination of genes, ↑ species diversity.

Question 17

What are the two processes that Meiosis takes advantage of to produce genetically distinct gametes?

Answer 17

By “crossing over” and independent assortment.

Question 18

What is independent assortment?

Answer 18

The different ways a cell organizes itself in metaphase I can lead to different gene combinations, as different genes are pulled to different ends of the spectrum.

Question 19

what are polar bodies? How many are made?

Answer 19

Certain cells made in meiosis in the female reproductive system have a smaller amount of cytoplasm and often die.

While 2 are directly made in the process, the first polar body can reproduce causing net total of 3.

Question 20

Are primary oocytes and spermatocytes created before, or after meiosis I?

Answer 20

Before.

Question 21

What does tetrad mean?

Answer 21

Homologous duplicated chromosomes that are aligned gene by gene.

4 chromatids…

Question 22

What are synapses?

Answer 22

The process of moving the homologous pairs together in mieosis

Question 23

What is “crossing over” in meiosis?

Answer 23

The exchange of DNA between paired homologous chromosomes in the tetrad in Prophase I

Question 24

What are the 4 parts of Prophase I?

Answer 24

1. Chromosomes condense and become visible
2. Nuclear membrane begins to dissolve
3. Synapsis form creating tetrads
4. the tetrads begin to cross over (exchanging genes)

Question 25

What are the 3 parts of Metaphase I?

Answer 25

1. Homologous chromosomes attach to microtubules (spindle fibers)
2. Homologous pairs line up at the equatorial plate (each pair is made of a paternal and maternal chromosome)
3. Each pair will align INDEPENDENTLY OF OTHER PAIRS (independent assortment)

Question 26

What are the only part of Anaphase I?

Answer 26

Homologous duplicated chromosomes in tetrads separate and move toward opposite poles.

Question 27

What is segregation in meiosis? When does it happen?

Answer 27

The separation of homologous pairs in such a way that either the maternal or paternal chromosome can be in either cell.

Anaphase I.

Question 28

What are the 2 parts of Telophase I and Cytokinesis I?

Answer 28

1. A nuclear membrane begins to form around each set of duplicated chromosomes.
2. two daughter cells form from cleavage furrows, or from the development of a cell wall through a cell plate.

Question 29

Meiosis II is very similar to what process? What is different?

Answer 29

Mitosis.

Because there are only 23 duplicated chromosomes, each cell becomes a haploid instead of a diploid.

Question 30

At the end of meiosis II how many gametes are produced, and how many are viable a male or female?

Answer 30

4 gametes are produced

Male - all four are viable
Female - one is viable; resulting in 3 polar bodies (not viable)

Question 31

What are the processes that increase genetic diversity in a species?

Answer 31

1. Crossing over in Meiosis
2. Independent Assortment in Meiosis
3. Fertilization

Question 31

What is the definition of nondisjunction?

Answer 31

Chromosomes or chromatids that do not separate as they should during meiosis.

This can lead to cells having too many, or too few chromosomes

Question 32

What is the definition of monosomy?

Answer 32

When one chromosome is lost due to nondisjunction, being unable to make a normal homologous pair.

Question 33

What is the definition of trisomy?

Answer 33

When one chromosome is gained due to nondisjunction, having three chromosomes instead of a normal homologous pair.

Question 34

why does a monosomy or a trisomy zygote impact the entire baby?

Answer 34

Because once they divide, all the cells in the body will contain an abnormal number of chromosomes.

Question 35

What is Chorionic Villus Sampling?

Answer 35

A process of collecting cells from the chorion to test for chromosomes.

Question 36

What is Amniocentesis?

Answer 36

A process by which a syringe draws fluid from the amniotic fluid to test its chromosomes.

Question 37

What is the nondisjunction that causes Down syndrome?

Answer 37

Trisomy 21.

Question 38

What is asexual reproduction? What is the key process involved in it?

Answer 38

A process in which a parent organism produces genetically identical offspring.

Mitosis

Question 39

Are gametes involved in Asexual Reproduction?

Answer 39

No gametes are involved.

Question 40

What is conjugation?

Answer 40

How a bacterium can transfer its genetic material to another bacterium.

Not a form of reporduction.

Question 41

What is parthenogenesis?

Answer 41

A form of asexual reproduction in which an unfertilized egg develops into an adult.

(Fertilized egg (female offspring, diploid), and Unfertilized Egg (Male offspring haploid).

Question 42

What cells are involved in Mitosis?

Answer 42

Stomatic cells

Question 43

What cells are involved in meiosis?

Answer 43

Germ cells

Question 44

What is the function of Mitosis?

Answer 44

Growth of organism and replacement. Maintains genetic continuity.

Question 45

What is the function of Meiosis?

Answer 45

Increases genetic diversity of offspring.