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Biology 1001 Lecture test 2

Terms in this set (89)

What are the functions of Cell Division?
- increase the number of cells
- growth
- reproduction of new skin cells called Blood Cells
- reproduces white blood cells during an infection
- tissue repair (after injury)
- reproduction of single celled organisms
How long is Cell Division needed?
Throughout all life
What is Apoptosis?
Programmed cell death
What are the functions of Apoptosis?
- Decrease the number of cells
- Remove unwanted cells during development for the organism to take shape
- Remove abnormal cells that could become cancerous
- Remove old and damaged cells
What type of organism is a human? What is the scientific name? How many chromosomes does a human have?
Animal
Homo Sapiens
46 (23 pairs)
In the Cell Cycle, what are the phases?
- Interphase (G1, S, G2)
- Mitosis (Prophase, Metaphase, Anaphase, Telophase)
- Cytokinesis
In the Cell Cycle, what is Interphase?
- spends most of the time here
- cells is performing its normal cell functions
- chromosomes are not visible
In the Cell Cycle, what are the stages of Interphase and what happens in each?
- G1
- organelles are copied
- nucleus accumulates materials needed to replicate DNA
- S
- Each chromosome is replicated (DNA Replication)
- G2
- Production of proteins needed for cell division (Mitosis)
- Example : (Centrioles)
In the Cell Cycle, each pair of duplicated chromosomes have how many sister chromatids?
2
During Mitosis, what happens in Prophase?
- Nuclear Membrane: breaks down
- Centrioles: move to opposite sides of the cell, and start to form spindle fibers (Proteins)
- Duplicated chromosomes: condense and become visable
During Mitosis, what happens in Metaphase?
- Chromosomes: line up in the middle of the cell (Metaphase Plate)
- Spindle Fibers: attach to each Sister Chromatid (At the Centromere)
During Mitosis, what happens during Anaphase?
- sister chromatids: pulled apart by spindle fibers, moving to opposite sides of the cell
- each separated sister chromatid is now called Daughter Chromosomes
During Mitosis, what happens during Telophase?
- Nuclear Membrane: forms around each set of daughter chromosomes
- Each nucleus contains: the same number and kinds of chromosomes; identical to original parent cell
- Spindle Fibers: disappear
During Cytokinesis, What is a cleavage furrow and what type of cell does this appear?
- Cleavage Furrow: indentation of cell membrane (between the two daughter nuclei
- Appears in Animal Cells
During Cytokinesis, What is a cell plate and what type of cell does this appear?
- Cell Plate: Newly formed cell membrane, expands outward until it reaches the old cell membrane and fuses with it (Releases molecules that form the new cell wall)
- Appears in Plant Cells
What are the Checkpoints in Cell Cycle?
G1 checkpoint
- repairs damaged DNA
G2 checkpoint
- any errors made to DNA during replication is fixed
M checkpoint
- checks spindle fibers assembly and stops the cycle of chromosomes are not being distributed correctly
What is Cancer?
Uncontrolled cell division and growth
How do normal cells vary from cancerous cells?
Normal
- specialized
- normal nuclei
- undergo apoptosis
- stop growing once in contact with neighbor cell

Cancerous
- not specialized
- abnormal about of chromosomes in nuclei
- repeatedly duplicates
- piles upon each other to form a tumor
What is Angiogenesis?
the formation of new blood vessels
What is Metastasis?
Motile- able to travel through the blood and lymphatic vessels to other parts of the body
What are Proto-oncogenes?
Encoded proteins that promote the cell cycle and prevent apoptosis
(RAS Protein: activated when a growth factor binds to the RAS Protein on the cell structure)
What are Tumor Repressor Genes?
Encoded Proteins that stop the cell cycle and promote apoptosis
(p53 Protein: checks DNA for damage before the cell proceeds through the G1 checkpoint
What phase of the cell cycle last the longest?
Interphase
If a parental cell has 14 chromosomes prior to mitosis, how many chromosome will each daughter cell have after mitosis?
14
The Division of the Nucleus is called?

The Division of the Cytoplasm is called?
Mitosis, Cytokinesis
Susan was examining a cell under the microscope and noticed the formation of a cell plate in the midline of the cell and the formation of nuclei at opposite poles of the cell.

a) what type of cell is this?
b) what process is the cell going through?
a) Plant Cell
b) Cytokinesis
BPA is a chemical compound that has historically been used in manufacturing of plastic products. However, cells often mistake BPA for hormones that accelerate the cell cycle. Would BPA act as an internal or external signal?
External Signal
What are Gametes?
Sperm and Egg Cells
What are Somatic Cells?
Body Cells
What types of cells does Meiosis take place in?
Gametes (Sex Cells)
What is a Haploid: n ?
n: number of different chromosomes in a cell,
23 in total (unpaired)
"Half the number of chromosomes"
What is a Diploid: n?
23 pairs (Total of 46 chromosomes)
What are Homologous Chromosomes?
Members of each pair.
One from mother and one from father
- looks like alike, length and shape
- contain the same type of genes arranged in the same order (genes for same traits)
What is a Karyotype?
Image of chromosomes arranged by pairs according to their size, shape and banding pattern
- 22 pairs of autosomes (same for male and female)
- 1 pair of sex chromosomes (XX=female, XY=Male)
What are the stage of Meiosis? what happens in them?
Meiosis-I
- diploid stem cells divide to make 2 haploid cells
Meiosis-II
- the two haploid cells divide to form another 2 haploid cells (4 in total) (Chromosomes are not identical)
When are chromosomes replicated?
Before Meiosis-I
In Meiosis-I, what does Prophase-I look like?
- Nuclear Membrane disappears and spindle fiber begin to form
- Synapse: Homologous Chromosomes line up side by side ( each has identical sister chromatid)
- Crossing Over: Non-sister Chromatids of homologous chromosomes exchange genetic material (sister chromatids are no longer identical)
In Meiosis-I, what does Metaphase-I look like?
homologous chromosomes are lining up side by side at metaphase plate
In Meiosis-I, what does Anaphase-I look like?
Homologous chromosomes are pulled apart
Independent Assortment: homologous chromosomes separate randomly
Cells with differentiate with combinations of maternal and paternal chromosomes
In Meiosis-I, what does Telophase-I look like?
Nuclear membrane forms around daughter chromosomes and spindle fibers disappear
Cleavage Furrow forms
What is Interkinesis?
The period of time between meiosis-I and meiosis-II
What is Meiosis-II similar to?
Mitosis
What happens in Meiosis-II?
Each haploid daughter cell from meiosis-I divides to form a total of four haploid daughter cells
In Meiosis-II, what does Prophase-II look like?
Spindle fibers form and the nuclear membrane disappears
In Meiosis-II, what does Metaphase-II look like?
- haploid number of chromosomes (each consisting of 2 sister chromatids) line up in the center of the cell
- spindle fiber attach to the sister chromatids
In Meiosis-II, What does Anaphase-II look like?
Sister Chromatids separate and move to opposite ends of the cells
In Meiosis-II, What does Telophase-II look like?
The nuclear membrane forms around the daughter chromosomes and spindle fibers disappear
The Cleavage Furrow forms
In Meiosis-I and Meiosis-II, what happens during Cytokinesis?
The Cytoplasm pinches off to form two new daughter cells
What happens in Mitosis?
Prophase- no pairing of chromosomes
Metaphase- duplicated chromosomes line up at middle
Anaphase- sister chromatids move to separate ends of cell
Telophase- 2 diploid daughter cells that are identical to parent
What happens in Meiosis-I?
Prophase-1 - pairing of homologous chromosomes
Metaphase-I - Duplicated chromosomes line in homologous pairs
Anaphase-I - homologous chromosomes separate to ends of cell
Telophase-I - two haploid daughter cells (not identical)
What happens in Meiosis-II?
Prophase-II - no pairing of chromosomes
Metaphase-II - haploid number of duplicated chromosome line up
Anaphase-II - sister chromatids (23 sets) separate to ends of cell
Telophase-II - four haploid daughter cells (not identical)
What is Spermatogenesis?
- The formation of Sperm
- Begins when a male reaches Puberty
- Produces 4 sperm cells per meiosis
- Continues throughout life
What is Oogenesis?
- The production of an oocyte
- Begins before birth
- Development stops at Prophase-I until reaches puberty
- After Puberty one oocyte per month completes Meiosis-I and stops at Metaphase-II
- Meiosis-II is only completed once oocyte is fertilized
What is Nondisjunction?
The Having of more or less chromosomes in a cell
In meiosis-I if non-disjunction happens what is the alteration?
Nondisjunction during meiosis-I is result of one pair of homologous chromosomes failing to separate
- one daughter cell gets both pairs of the homologous chromosomes, which leads into meiosis-II with the end result being that 2 cells have no chromosomes while the other 2 have 2 chromosomes each
In meiosis-II if non-disjunction happens what is the alteration?
Nondisjunction in meiosis-II is result of sister chromatids of one chromosome failing to separate.
- the end result is two cells have 1 chromosome per cell but the other two cells, one has both chromosomes that failed to split
What does it something is Trisomy?
One type of chromosome is present in three copies (Down Syndrome, Trisomy 21)
What does it mean if something is Monosomy?
One type of chromosome is present in only one copy (Turner Syndrome)
What are the characters of Down Syndrome?
- Trisomy 21, had 47 Chromosomes, can appear in either gender
- Short stature, an eyelid fold, and stubby fingers
What are the characteristics of Poly-X Syndrome?
- XXX, has 47 chromosomes, present in females only
- multiple X chromosomes may be inactivated in the female's cells
What are the characteristics of Turner Syndrome?
- X (XO), has 45 chromosomes, present in females only
- short, with broad chest and webbed neck
- ovaries, uterine tubes, and uterus are very small and underdeveloped
What are the characteristics of Klinefelter Syndrome?
-XXY, has 47 chromosomes, present in males only
- large hands and feet and very long arms and legs
- the extra X chromosomes become Barr Bodies
- testes and prostate gland are underdeveloped
What are the characteristics of Jacob's Syndrome?
- XYY, has 47 chromosomes, present in males only
- does NOT appear to make an individual have a more aggressive personality
Crossing over occurs during which phase of Meiosis-I?
Does crossing over occur between sister chromatids of the same chromosome or between non-sister chromatids of homologous chromosomes?
Prophase-I
Non-Sister Chromatids
If a parental cell has 14 chromosomes prior to meiosis, how many chromosomes will each daughter cell have following meiosis?
7
During which phase of Meiosis do homologous chromosomes separate?
Meiosis-I Anaphase-I
During what phase of Meiosis do sister chromatids separate?
Meiosis-II Anaphase-II
Mitosis, Meiosis-I, or Meiosis-II
a) The parent cell has ten duplicated chromosomes and each daughter cell has five duplicated chromosomes
b) The parent cell has five duplicated chromosomes and each daughter cell has five chromosomes, consisting of one chromatid each
c) The parent cell has ten chromosomes and each daughter cell has ten chromosomes, consisting of one chromatid each
a) Meiosis-I
b) Meiosis-II
c) Mitosis
Which process may not go to completion? Spermatogenesis or Oogenesis?
Oogenesis
State whether each of the following is an example of trisomy or monosomy:
A) Turner Syndrome
B) Down Syndrome
C) Klinefelter Syndrome
A) Monosomy
B) Trisomy
C) Monosomy
What are alleles?
Alternative versions of genes for a particular trait
Inheriting of one allele from mother and one from father
How many alleles do sperm and eggs cells have?
1 allele
What is the Genotype?
alleles that the chromosomes carry that are responsible for a given trait
What is the Phenotype?
An individual's actual appearance due to genotype and environmental factors
What are the Dominant Genotypes?
Homozygote (AA)
Heterozygote (Aa)
What is the Recessive Genotype?
Homozygote (aa)
When using Two Trait Crossing and both parent's alleles are Heterozygous what is the ratio given for the Phenotype?
9:3:3:1
If both parents are affected but a child is unaffected this can be Autosomal Dominant if both parents are what?
Heterozygous
if both parents are unaffected, but a child is affected this can be Autosomal Recessive if both parents are what?
Heterzygous
What are carriers?
Heterozygous parent alleles, because they are unaffected but are capable of having a child with the genetic disorder
X-Linked traits are found on what type of chromosome?
X Chromosome
What is an example of an X-Linked Trait?
Color Blindness
When does Incomplete Dominance occur?
When a heterozygote is intermediate between the two homozygotes
Example: Wavy Hair
When does Co-Dominance occur?
When the alleles are equally expressed in a heterozygote
Example: Blood type (AB)
For each of the following, state whether a genotype or a type of gamete is represented:
1) G
2) GG
3) Tt
4) T
1) Gamete
2) Genotype
3) Genotype
4) Gamete
For each of the following, state whether a genotype or a type of gamete is represent:
1) Wc
2) GG
3) TTGG
4) WwCc
5) TW
1) Gamete
2) Genotype
3) Genotype
4) Genotype
5) Gamete
Assume that two parents with normal vision have a color-blind son. Which parent is responsible for the son's color blindness?
Mother (Carrier)
A women with type AB blood marries a man with type B blood. If they have children, what are the possible blood types of their children?
A, B, AB
A heterozygote for a particular trait exhibiting incomplete dominance will:
A) Exhibit an intermediate genotype
B) Express the recessive trait
C) Exhibit an intermediate phenotype
D) Express both alleles
C) Express an intermediate phenotype
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