Chapter 3

Question 1

Chromosomes

Answer 1

Structures within living cells that contain the genetic material

Genes are within chromosomes

Each chromosome contains a very long segment of DNA

Question 2

Chromatin

Answer 2

Complex between DNA and proteins

Question 3

Prokaryotes

Answer 3

Bacteria and Archaea

Chromosomes are not contained within a membrane-bound nucleus of the cell

Usually has a single type of circular chromosome in the nucleoid

Question 4

Eukaryotes

Answer 4

Single celled protist, some fungi, and complex multicellular species

Organelles: Membrane-bound compartments with specific functions

Question 5

Cytogenetics

Answer 5

The field of genetics that involves the microscopic examination of chromosomes

Question 6

Somatic cell

Answer 6

Any cell if the body that is not a gamete or precursor to a gamete

Question 7

Gametes or germ cells

Answer 7

Sperm and egg cells

Question 8

Karyotype

Answer 8

An organized representation of chromosomes within a cell

Reveals how many chromosomes are found within an actively dividing somatic cell

Question 9

Diploid

Answer 9

Two sets of chromosomes

Most eukaryotic species

Question 10

Homologs

Answer 10

The members of a pair of chromosomes

One from mother, one from father

If a particular gene is found on one homolog it is found on the other. However they may carry different versions of the gene (Alleles)

Question 11

How similar are Homologous chromosomes?

Answer 11

They usually differ by less than 1%

Question 12

How similar are sex chromosomes?

Answer 12

These chromosomes differ in size and genetic composition.

Certain genes that are found on the X are not found on the Y chromosome

Not homologous

Question 13

Asexual reproduction, bacterial proliferation

Answer 13

A pre-existing cell divides to produce two new cells.

Original cell is called the mother cell and the new cells are called the two daughter cells

Question 14

Binary fission

Answer 14

The two daughter cells become separated from each other by the formation of a septum

Each cell receives a copy of the chromosome a genetic material

Protein FtsZ: Important in cell division, assembles until into a ring at the site of the septum to produce a new cell wall between daughter cells

Question 15

Cell cycle

Answer 15

G (gap)
S (synthesis)
M (Mitosis)

Interphase: G1, S, G2

G0: no advancement in cell cycle (nerve cells)

Question 16

Chromatids

Answer 16

After replication, the two copies of a chromosome

Joined to each other at a region of DNA called the centromere

Called sister chromatids or dyad as a pair

A single chromatid within a dyad is called a monad

Question 17

Kintechore

Answer 17

Group of proteins that are bound to the centromere that help for the sister chromatids together and sort chromosomes

Question 18

Mitosis

Answer 18

The distribution of replicated chromosomes, dividing one cell nucleus into two nuclei, so each daughter cell receives the same complement of chromosomes

Question 19

Biologist Walther Fleming

Answer 19

First observed mitosis microscopically in the 1870s

Studying dividing epithelial cells of salamander larvae

“Two parallel threads”

Question 20

Microtubule organizing center

Answer 20

Structures found in eukaryotic cells from which microtubules grow

2 MTOCs or centrosomes forms the mitotic spindle (located at spindle pole

Each centrosome has 2 centrioles

Question 21

Aster microtubules

Answer 21

Emanate outward from the centrosome toward the plasma membrane

Important for the positioning of spindle apparatus within the cell and in the later process of cytokinesis

Question 22

Polar microtubules

Answer 22

Project toward the region where the chromosomes will be found during mitosis

Overlap with each other and play a role in separation of the two poles by pushing them apart

Question 23

Kinetochore microtubule

Answer 23

Attached to Kinetochores

Question 24

Know every detail of mitosis

Answer 24

Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Cytokinesis

Question 25

Know every detail of meiosis

Answer 25

Prophase Meiosis I
Metaphase Meiosis I
Anaphase Meiosis I
Telophase Meiosis I
Meiosis II

Question 26

Meiosis vs Mitosis

Answer 26

Mitosis produces 2 diploid daughter cells with six chromosomes each

Meiosis produced 4 haploid daughter cells with three chromosomes each

Question 27

Sexual reproduction

Answer 27

Two gametes fuse with each other in the process of fertilization to begin the life of a new organism

Question 28

Isogamous

Answer 28

Gametes that are morphologically similar

Question 29

Heterogamous

Answer 29

Produce two morphologically different types of gametes

Question 30

Spermatogenesis

Answer 30

Production of sperm, occurs within glands known as testes

One remains as a spermatogonial cell and in becomes a primary spermatocyte

Question 31

Oogenesis

Answer 31

Production of egg cells, occurs within specialized diploid cells of the ovary known as oogonia

Question 32

Oocyte

Answer 32

a cell in an ovary which may undergo meiotic division to form an ovum

1 million per ovary

Arrested until sexual maturity

Question 33

Plants gametes

Answer 33

Gametophyte: haploid generation

Sporophyte: diploid generation

Question 34

Plant gametophytes

Answer 34

Male gametophyte of plant is a pollen grain (haploid)

Female gametophyte of a plant is an embryo sac (haploid)

Plants produce gametes by mitosis

Question 35

Endosperm

Answer 35

Food storing tissue

Question 36

Chromosome theory of inheritance

Answer 36

1. Chromosomes contain genetic material
2. Chromosomes are replicated and passed
3. Diploid or haploid
4. Haploid cells segregate
5. Each parent contributes a set of chromosomes

Question 37

Heterogametic

Answer 37

Two types of Sperm: one that carries an X and another with a Y

Male

Question 38

Homogametic sex

Answer 38

All eggs carry X chromosome

Female

Question 39

X linked genes or alleles

Answer 39

Genes that are physically located within the X chromosome

Question 40

Testcross

Answer 40

An individual with a dominant phenotype and unknown genotype is crossed to an individual with a recessive phenotype