Chapter 2 Test Flashcards
1
Q
What are the functions of cell division?
A
There are three main functions of cell division: growth, repair, and reproduction.
2
Q
How does an organism grow?
A
- Unicellular growth: Grow in size
- Multicellular growth: Grow in cell quantity
3
Q
How does an organism repair?
A
- An organism repairs through cell division
4
Q
How does an organism reproduce?
A
- Unicellular: Cell division (Asexual Reproduction) • Binary Fission • Budding • Vegetative Reproduction • Fragmentation • Spore Formation
5
Q
What is binary fission?
A
- A form of asexual reproductions used by single celled
organisms o produce two genetically identical
daughter cells
• Only single-celled organisms: Protists (Amoebas),
algae, bacteria
6
Q
What is Budding?
A
- A type of asexual reproduction in which the offspring
begnins as a small growth (Called a bud) on the parent
• Bud undergoes cell division and grows in size before
breaking off
• Occurs in multicellular and unicellular organisms:
Yeast, hydra
7
Q
What is Vegetative Reproduction?
A
- Asexual reproduction in plants; includes producing
runners, bulbs, tubers and cuttings.
• Examples: Aspen and lilac
8
Q
What are runners?
A
- Runners are a type of stem that grows horizontally
along the surface of a soil
• Runners grow their own roots and become an
independent plant.
9
Q
What are shoots?
A
- Shoots are send out from the base of a trunk or
underground stem, which grow into a new
independent lant
10
Q
What is Fragmentation?
A
- Fragmentation a type of asexua; reproduction in which
a small part of an animal breaks off and grows into a
new organism
• Cannot occur without regeneration
• Examples: Sea star, planarian, flatworms, and
planaria
11
Q
What is Regeneration?
A
- Regeneration is the ability to regrow a body part, a
tissue, or an organ
12
Q
What is Spore Formation?
A
- A form of reproduction using spores
• Spores: Cells with thick walls
13
Q
What are some characteristics of asexual reproduction
A
- Only one organism is needed to reproduce
- All the offspring are genetically identical to each other
and to the parent organism - A single organism can produce large numbers of
offspring
14
Q
What happens in sexual reproduction?
A
- The parents contribute genetic material in
specialized sex cells (Egg cell and a sperm cell/zygote)
15
Q
What is the Nucleus?
A
- Organelle that produces and assembles ribosomes
• Controls all cell activities including cell division
• Surrounded by the nuclear membrane
• Contains chromosomes
16
Q
What are chromosomes?
A
- Genetic material contained in the cell that controls all
cell activities
• Human cells have 23 pairs of chromosomes (46)
• Made out of a long strand of DNA and proteins
17
Q
What is DNA?
A
- A long molecule that provides instructions for
developing a cell
• Looks like a twisted ladder
• DNA molecule is organized into genes
18
Q
What is the nucleolus?
A
- Found in the core of the nucleus
• Site for making and assembling ribosomes- Ribosomes then move into the cytoplasm
19
Q
What are ribosomes?
A
- Tiny organelles in the cytoplasm
• Make up the proteins that allow the cell to function
correctly
• Either free in the cytoplasm, or attached to
endoplasmic reticulum
20
Q
What is Endoplasmic Reticulum?
A
- Endoplasmic reticulum is a series of tubes and
flattened sacs that transport materials throughout the
cell.
• Two types: Rough ER and Smooth ER
21
Q
What is Rough ER?
A
- Rough ER: ER that has ribosomes
• Transport proteins throughout the cell.
22
Q
What is smooth ER?
A
- Smooth ER: ER that has no ribosomes
• Manufactures and transports fats in the cell
23
Q
What is Cytoplasm?
A
- Cytoplasm: Jelly like substance that holds and contains
all organelles
• Most cell activities occur in the cytoplasm:
Absorption, transportation, and processing of nutrients
• Contains tiny microtubes that allow movement and
support of the organelles
24
Q
What is Centrioles?
A
- Organelles made out of special microtubes.
• Found in most animal cells
• Active during cell division
25
What is DNA made out of?
- DNA is made out of two strands of smaller molecules,
called nucleotides
• Nucleotides are composed of a phosphate, sugar,
and a nitrogenous base
• Sides of DNA ladder are made of sugar and
phosphate molecules
• Rungs of DNA ladder are made of pairs of
nitrogenous bases
26
What are the four types of nitrogenous bases?
- Adenine (A), Thymine (T), Cytosine (C), and Guanine (G)
27
What are the pairs of nitrogenous bases?
- Adenine and thymine (A-T), or cytosine and guanine
| (C- G)
28
How does DNA replicate?
1. Each DNA molecule clones itself
2. Each molecules splits in many places between the
pairs of bases, like a broken zipper
3. New bases join up with the bases on each of the
opened side of the ladder to form two identical DNA
molecules
29
What is the genetic code?
- Genetic Code: Four Nitrogenous bases that form a
three-letter word that are three bases long
• Each three-letter word produces one of 20 amino
acids
• All three letter words form instructions for all body
cells for follow
30
What are Amino acids?
- Amino acids: Molecules that make up proteins; 20
types
• Different combinations of amino acids form different
proteins
• Amino acids are either manufactured by your body or
are obtained from the food you eat
31
What are proteins?
- Proteins determine the characteristics of organisms
32
What are genes?
- Gene: Short section of DNA that contains the
instructions to make a specific protein
• Instructions are determined by the order of the bases
• All of an organism's genes is called the genome
33
How does RNA form?
1. The DNA segment that makes up a gene is used to
make RNA
2. A gene segment of DNA separates and an RNA
molecule is constructed from one half of the DNA
34
What is RNA?
- RNA is similar to stricture to DNA, but only has one
strand
• RNA carries the code from a gene segment of the
DNA and travels out of the nucleus to a ribosome in
the cytoplasm
- Ribosomes follow the instructions on the RNA and
assembles a amino acid to make the protein
35
What are the variations of genes between the same species?
- All members of the same species have the same
number and type of genes
• Species also have different versions of genes that
results in different variations, or traits
36
What is the cell cycle?
- Interphase and cell division
37
What percent does interphase make up the cell cycle?
- 90%
38
What occurs during interphase?
- During interphase, the cell makes copies of each
organelle
• Once big enough, it will also make copies of it's
chromosomes
39
What is a sister chromatids?
- Sister Chromatids: A chromosome and its copy
40
What is the parent cell?
- Parent cell: Cell before it divides
41
What are daughter cells?
- Daughter cells: Offspring of a parent cell
42
What are the two processes that make up cell division?
- Mitosis and cytokinesis
43
What must occur before cell division?
- DNA synthesis
44
What is mitosis?
```
- Mitosis: Process that divides nuclear material during
cell division
• 4 parts:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
```
45
What is prophase?
- Prophase: First stage of mitosis
• Sister chromatids have shortened, thickened, and are
joined to the center like an x
• Sister chromatids are now visible with a light
microscope
• Nucleolus is no longer visible
• Nuclear membrane has broken down and
chromosomes spread in the cytoplasm
• Centrioles in animal cells move to opposite poles to
form spindle fibers
• Spindle fibers form the spindle
46
What are spindle fibers?
• Spindle fibers: Microtubules that grow toward the
| center of the cell
47
What is Metaphase?
- Metaphase: Second stage of mitosis
• Spindle is formed
• Sister chromatids attach to the spindle fibers and line
up along the middle of the cell
48
What is Anaphase?
- Anaphase: Third stage of mitosis
• Sister chromatids are pulled apart by the spindle and
move to opposite poles
• Chromatids are now called chromosomes
49
What is Telophase?
- Telophase: Last stage of mitosis
• New chromosomes have reached opposite poles
• Events op prophase happen in reverse
• Original nucleus has divided
50
What is cytokinesis?
- Cytokinesis: During cell division, the method that splits
the cytoplasm and the remainder of the organelles in
half; it generally starts before mitosis is complete
• Begins during telophase
• Divides the cytoplasm into two daughter cells
• Indentation of cell membrane in animal cells
Plant cells:
• No indentation in plant cells, instead membrane-
bound vesicles form between the two nuclei
• The Vesicles form together to form the cell plate
• Cell plate grows outward toward the cell membrane,
forming a cell membrane and cell wall for each
daughter cell
51
What is a mutation?
- Mutation: A change in the DNA
| • Can be beneficial, neutral, or harmful
52
How are genetic diseases such as cancer formed?
- By harmful mutations
53
What is cancer?
- Cancer: A disease in which cells divide very rapidly and
uncontrollably; caused by a mutation in the genes that
control cell division
• Cells affected are called cancer cells, which have a
larger nucleus due to cancer cells always dividing
• Cancer cells don't carry out normal cell functions and
use more nutrients
• Cancer cells can divide even If separated from
neighbouring cells
54
Why do some cells have a varying length of cell cycles?
- Because some cells have different life spans, E.g. Bone
| marrow and skin cells
55
What are tumours?
- Tumours: Abnormal masses of cancer cells
| • Two types, Benign and malignant tumours?
56
What are benign tumours?
- Benign tumours: A mass of cells that grows but stays in
one place and usually does not interfere with the
normal functioning of the surrounding tissue and
organs
• Can be removed by surgery
• Example: Wart
57
What are Malignant tumours?
- Malignant tumours: A mass of cells that invades the
surrounding tissue and interferes with the normal
functioning of tissues and organs
58
What is metastasis?
- Metastasis: Spread of cancer cells way from their
| original location
59
What are some causes of cancer?
- Diet, Tobacco, virus, sunlight
60
What is a carcinogen?
- Carcinogen: Anything that can cause cancer
61
What are some methods of treating cancer?
- Radiation, Surgery, and Chemotherapy
62
What is cancer radiation treatment?
- Radiation: Kills cancer cells and good cells by
disrupting cell division
• Can cause hair loss, burns, nausea and vomiting
63
What is chemotherapy cancer treatment?
- Chemotherapy involves using drugs to stop the cancer
cells from dividing
• Can cause hair loss, burns, nausea and vomiting
64
What is a clone?
- Clone: An offspring of asexual reproduction;
genetically identical to the parent and to other
offspring produced asexually by the parent
65
What is sexual reproduction?
- Sexual reproduction: Two separate organisms
contribute genetic information to produce offspring
that are genetically different from both parents
66
What is a spindle?
- Spindle: Moves the chromatids during the later phases
| of cell division; made of spindle fibres
67
What is a trait?
- Trait: One version of a characteristic.
68
What is the nuclear membrane?
- Nuclear membrane: surrounds the nucleus and allows
| certain materials to pass or go through it
