Lesson 4: Cell Cycle

Question 1

Nutrients and wastes move across a cell by ___.

Answer 1

Diffusion

Question 2

Small cells have a (higher/lower) ___ compared to larger cells

Answer 2

higher; surface area to volume ratio

Question 3

Cells constantly need to get ___ in and ___ out.

Answer 3

nutrients; waste

Question 4

As the size of a cell (increases/decreases), the ratio between the surface area and volume (increases/decreases).

Answer 4

increases; decreases

Question 5

A smaller cell has more ___ to quickly send materials across the membrane .

Answer 5

surface area (ratio)

Question 6

If a cell gets too large; it must ___.

Answer 6

divide

Question 7

Genome

Answer 7

the complete set of an organism’s DNA

Question 8

DNA

Answer 8

the genetic code of an organism

Question 9

Chromosomes

Answer 9

packages of DNA; located in the nucleus of each cell

Question 10

Genes

Answer 10

sequences of DNA that code for a specific protein

Question 11

List these terms from smallest to biggest:

Genome
Gene
DNA
Chromosome

Answer 11

1. Gene
2. DNA
3. Chromosome
4. Genome

Question 12

Prokaryotic chromosomes are ___.

Answer 12

simple circles and clumps of DNA in a nucleoid region

Question 13

Eukaryotic chromosomes are ___.

Answer 13

very complex and made of DNA coiled around proteins (histones)

Question 14

Homologous chromosomes

Answer 14

● Pairs of chromosomes that exist in all sexually reproducing species
● Each pair contains genes for the same types of traits
● Each pair represents one chromosome from each parent, meaning they likely have different traits

Question 15

Chromosomes

Answer 15

● Before cell division, the chromosomes copy themselves
● The replicated chromosome is called sister chromatids
● They are attached to a centromere

Question 16

Cells continuously divide in order to ___.

Answer 16

repair or replace cells that die

Question 17

Cells divide rapidly during the ___ of multicellular organisms.

Answer 17

growth

Question 18

Cell Cycle

Answer 18

The life cycle of a cell; from division to division

Question 19

5 Stages of the Cell Cycle

Answer 19

1. G1: Growth phase of the cell
2. S: DNA is copied
3. G2: Prep for mitosis, organelles are copied
4. M: Mitosis occurs, nucleus divides
5. C: Cytokinesis, cell/cytoplasm divides

Question 20

What parts of the cell cycle are a part of interphase?

Answer 20

G1, S, G2

Question 21

Most of a cell’s life is spent in ___.

Answer 21

Interphase

Question 22

What triggers cell division?

Answer 22

● Size: If a cell grows so large that there is too much volume for the surface area, it will divide
● Growth factors: Chemicals released by cells that encourage other cells to divide

Question 23

Mitosis

Answer 23

a type of cell division that divides the nucleus and produces identical, diploid cells (occurs in body, or somatic, cells)

Question 24

Four stages of Mitosis

Answer 24

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

Question 25

Prophase

Answer 25

● Chromosomes appear ● Nuclear envelope breaks down ● Spindle fibers appear (protein ropes that pull chromosomes apart)

Question 25

Metaphase

Answer 25

● Meta = middle ● Spindle fibers line up chromosomes on the equator ● They attach to the centromeres

Question 26

Anaphase

Answer 26

● Sister chromatids are pulled apart by spindle fibers (x2 the amount of chromosomes) ● Each chromatid (single chromosome) pulled to opposite poles towards the centrioles

Question 27

Telophase

Answer 27

● Chromosomes uncoil on separate sides of the cell ● 2 new nuclear envelopes appear (almost 2 nuclei but still one cell)

Question 28

Cancerous cells

Answer 28

a single cell that has undergone mutations in its DNA

Question 29

Instead of maturing and dying normally, cancerous cells ___

Answer 29

reproduce uncontrollably

Question 30

Density Dependent Inhibition (DDI)

Answer 30

When cells stop dividing when crowded (cancer cells ignore DDI)

Question 31

Apoptosis

Answer 31

Programmed cell death (cancer cells ignore apoptosis)

Question 32

Tumors

Answer 32

The result of uncontrolled cell division (a big "lump" of cells)

Question 33

Benign tumors

Answer 33

Non-harmful tumors

Question 34

Malignant tumors

Answer 34

Harmful tumors

Question 35

Metastasize

Answer 35

invade other tissues

Question 36

Cancer is multi___

Answer 36

factorial

Question 37

Lifestyle risks

Answer 37

● Smoking ● UV Rays ● Diet ● Lack of Exercise ● Obesity (Last three are usually grouped)

Question 38

Environmental Risks

Answer 38

● 2nd-hand smoke ● Air/Industrial pollution ● Chemical exposures

Question 39

Inherited Risks

Answer 39

● Gene mutations are passed on to offspring

Question 40

Cancer treatments

Answer 40

● Chemotherapy ● Radiation ● Removal of tumors ● Immunotherapy ● Blood and marrow transplant ● New gene therapy, Stem Cells, Virus Therapy (NOT cures)

Question 41

Diploid (2N)

Answer 41

two copies of each chromosome (46)

Question 42

Haploid (N)

Answer 42

one copy of chromosomes given to offspring (23)

Question 43

Meiosis

Answer 43

a special type of cell division that produces gametes (occurs in testes and ovaries), 1 diploid cell (2N) - 4 haploid cells (N)

Question 44

Gametes

Answer 44

sex cells (sperm and egg)

Question 45

2 gametes form a ___

Answer 45

zygote (egg (N) + sperm (N) - zygote (2N))

Question 46

Meiosis Overview

Answer 46

2 rounds of cell divisions 1. Meiosis 1: ● DNA replicates ● Pair of homologous chromosomes separate 2. Meiosis 2: ● Same steps but no DNA replication ● Sister chromatids separate ● Cells now have 1/2 of their original DNA

Question 47

Crossing over

Answer 47

● Occurs during Prophase 1 ● Replicated homologous chromosomes pair up and form a tetrad ● Some DNA gets swapped

Question 48

Independent Assortment

Answer 48

haploid cells have randomly assorted DNA from both parents

Question 49

Crossing over and Independent Assortment lead to ___

Answer 49

greater genetic diversity (good for species survival, occurs in metaphase 1)

Question 50

Monosomy

Answer 50

A missing chromosome. Usually results in death during fetal development

Question 51

Trisomy

Answer 51

An extra chromosome. Usually results in a "chromosomal disorder" like down syndrome

Question 52

Karyotype

Answer 52

a picture of all the chromosomes used to look for abnormalities

Question 53

Nondisjunction

Answer 53

when homologous pairs or sister chromatids fail to separate (leads to monosomy + trisomy)