Unit 5 Cellular Reproduction

Question 1

What is cell division

Answer 1

splitting of the parent cell into two identical daughter cells

Question 2

What is asexual reproduction

Answer 2

Cell division that results in the reproduction of a whole organism

-cloning

Question 3

What is sexual reproduction

Answer 3

reproduction that requires the fusion of gametes

Question 4

What are the steps of binary fission

Answer 4

Dividing in half
-happens in prokaryotes

Question 5

What are gametes

Answer 5

egg and sperm cells

Question 6

What is a zygote

Answer 6

Fertilized egg

Question 7

What is the cell cycle

Answer 7

sequence of events from the instant a cell is formed to the moment it divides into two new daughter cells

Question 8

What are the 2 main stages of the cell cycle

Answer 8

1. Interphase: growing phase
   -90% of cell cycle
2. Mitotic phase: Cell division

Question 9

what are the 3 phases of interphase

Answer 9

1. G1 phase: first gap
2. S phase: synthesis phase
3. G2 phase: Second gap

Question 10

What happens in G1 phase

Answer 10

-normal cellular functions take place

Question 11

What happens in S phase

Answer 11

DNA replication takes place

Question 12

What happens in G2 phase

Answer 12

-cell finishes preparing for cell division

Question 13

What are the 2 stages of the Mitotic phase

Answer 13

1. Mitosis
2. Cytokinesis

Question 14

What is mitosis

Answer 14

The division of the nucleus and its continents

Question 15

What is cytokinesis

Answer 15

the division of the cytoplasm and separation of the 2 daughter cells

Question 16

What happens in Prophase

Answer 16

• Chromatin coils into chromosomes
• mitotic spindle emerges from the centrosomes
• centrosomes separate

Question 17

What happens during Prometaphase

Answer 17

• Nuclear envelop disappears
• Mitotic spindle ends reach chromosomes
• some attach to the middle of the chromosome

Question 18

What happens during Metaphase

Answer 18

• Chromosomes line up on the metaphase plate
  (imaginary line in the middle)

Question 19

What happens during Anaphase

Answer 19

• Chromosomes come apart and the sister chromatids separate

Question 20

What happens during Telophase and Cytokinesis

Answer 20

• Daughter nuclei are formed at the poles of the cell
• Mitotic spindle disappears
• Mitosis is finished

Question 21

What happens during cytokinesis in animal cells

Answer 21

a Cleavage Furrow:
-microfilaments and myosin form a ring at the furrow site

-Furrow deepens and eventually pinches the parents cell into 2

Question 22

What happens during cytokinesis in plant cells

Answer 22

Vesicles transport new cell wall material to the middle of the parents cell
- creates a divider between the two daughter cells

Question 23

What are the environmental factors that influence cell division

Answer 23

1. Anchorage dependance: must be in contact with a solid surface to divide
2. Density-dependent inhibition: crowded cells stop dividing
3. Chemical factors: need certain nutrients to grow
4. Growth factors: divide if certain proteins are present

Question 24

What are tumors

Answer 24

mass of abnormally growing cells within a normal tissue

Question 25

What are the 2 different types of tumors

Answer 25

Benign tumor: -abnormally cells remain at their original location Malignant tumor: -Abnormally reproducing cells that can spread into other tissues in other part of the body

Question 26

what are Somatic cells

Answer 26

Typical body cells - human somatic cells have 46 chromosomes

Question 27

What are Homologous Chromosomes

Answer 27

- match in length, centromere position and staining pattern - carry same genes for the same inherited characters

Question 28

What are sex chromosomes

Answer 28

chromosomes that determine the sex of an individual

Question 29

What are Autosomes

Answer 29

All other chromosomes other than sex chromosomes - humans have 44 autosomes (22 sets of homologous chromosomes) and 2 sex chromosomes

Question 30

What are Diploid cells

Answer 30

A cell that contains two sets of chromosomes abbreviated to 2n

Question 31

What are Haploid cells

Answer 31

A cell with a single set of chromosomes humans: 1n = 23 -occurs in gametes

Question 32

What is the life cycle

Answer 32

sequence of stages for an organism from fertilization until the production of its own offspring

Question 33

What are the stages of Meiosis

Answer 33

1. Interphase: chromosomes are duplicated 2. Meiosis 1: the first division takes place 3. Meiosis 2: The separation of the two sister chromatids

Question 34

What happens during interphase in meiosis

Answer 34

- chromosomes duplicate - centrosome duplicates

Question 35

What happens during Prophase 1 in meiosis

Answer 35

- homologous chromosomes come together as pairs - crossing over - chromosomes coil tightly and a spindle forms

Question 36

What happens during Metaphase 1 in meiosis

Answer 36

- Chromosome tetrads are aligned at the metaphase plate

Question 37

What happens during Anaphase 1 in meiosis

Answer 37

- Chromosomes migrate to the two poles of the cell - sister chromatids of a chromosome stay attached to each other

Question 38

What happens during telophase 1 and cytokinesis in meiosis

Answer 38

- each pole has a haploid chromosome set - cytokinesis (same as mitosis) -to haploid daughter cells are formed

Question 39

What happens during meiosis 2

Answer 39

Prophase 2: spindles move chromosomes to the center of the cell Metaphase 2: chromosomes are aligned at the metaphase plate Anaphase 2: centromere of sister chromatids separate and move to opposite poles Telophase 2 and cytokinesis: nuclei form at the cell poles and the cell undergoes cytokinesis (Making 4 haploid daughter cells)

Question 40

what are recombinant chromosomes

Answer 40

chromosomes that carry DNA from 2 different parents

Question 41

How to calculate combinations of chromosomes

Question 42

What is the process of nondisjunction

Answer 42

When chromosome pair fails to separate - in meiosis 1; the homologous chromosome stay together and dont go to opposite poles -half of gametes get 2 of the same chromosome - half gametes do not get that chromosome at all

Question 43

What is deletion

Answer 43

chromosome fragment becomes detached

Question 44

What is duplication

Answer 44

Chromosome fragment that detaches and attaches to the sister chromatid

Question 45

what is inversion

Answer 45

chromosome fragment reattaches to the same chromosome but in reverse orientation

Question 46

What is Translocation

Answer 46

Fragment joins a non-homologous chromosome