biology 3rd Flashcards


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1

Mitosis divide cells to produce what?

identical daughter cells

2

What is Mitosis essential for? (function) List all 2.

1. Growth and development
2. reproduction
3. tissue renewal

3

What are the 3 subphases of interphase?

1. G1- gap phase
2. S- Synthesis
3. G2- 2nd gap phase

4

What does each of the 3 subphases responsible for?
G1, Synthesis, G2 (2 idea)

1. G1- cellular growth, doubles organelle & membrane mass & cytoplasm
2. synthesis- DNA is DUPLICATED
3. G2- continue growth, prepare for cell division

5

How many chromosomes are in a human somatic cell? How many are in ONE set?

46 chromosomes
23- each parents

6

What does Chromatin consist of? What does it do?

DNA+ protein
Helps organize the DNA

7

What is the difference between chromosome, chromatIDS, and chromatIN

chromosome- consist of two into one whole
chromatids- "sisters" two pairs of dna
chromatINS- DNA+ protein that organize DNA

8

During what phase do sister chromatids separate? What happened?

Anaphase.
Centromere splits so each chromatID (two) is now a chromosome (one)

9

During which phase do chromosome first become visible?

propase

10

Cytokinesis begins in which phase?

telophase

11

During which phase does the DNA make a copy of itself?

interphase

12
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1) chromatid
2) chromosome

13

Where are microtubules organized for mitosis?

centrosomes

14

Single Centrosome replicates during what phase? Mitosis.

interphrase bc doubling everything

15
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What Phase is this? What is happening to the structure of DNA? What is forming? What isn't there?

Prophase.

DNA condensed.
Mitotic spindle begins to form.
No Nucleolus.

16
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What Phase is this? Structure of DNA? Structure of nuclear envelope? What does it have that prophase doesnt?

- End of interphase; G2

- spaghetti DNA, DNA DUPLICATED
- nuclear envelope isnt broken
- nucleolus

17
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What Phase is this? What is happening?

Anaphase

-sister chromatids are separating

18
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What Phase is this? What is happening?

Metaphase (Longest phase)

Chromosomes are lined up on the metaphase plate

19
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What phase is this? What is reforming (2)? What is happening to DNA?

Telophase

-nuclear envelope & Nucleolus
- decondensed into spaghetti

20
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What phase is this? What is happening to nuclear envelope? DNA structure? microtubules?

-Prometaphase

- Nuclear envelope= fragmented
- Dna becomes shorter
- microtubules are connected to kinetochore

21
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What phase is this/ what does it divide? What is formed? When does it begin?

Cytokinesis

- Divides plasma membrane
- cleavage furrow
- late anaphase or early telophase

22

Cytokinesis depends on cytoskeletal components:

____: separate plasma membrane
____: separate chromosomes

actin
microtubules

23

What controls whether or not a cell will divide? (3 factors)

conditions...
1. intracellular conditions (within cell)
2. extracellular conditions (outside)

24

What are the three "checkpoints" in cell cycle of mitosis?

G1
G2
M

25

What phase are most human cell in? What kind of cells undergo this?

- G0 phase (non-dividing phase) Cell that doesn't receive a "go" signal.

- Damaged liver cells
- Mature muscle and nerve cells

26

G1 checkpoint:
1. Function of PDGF (platelet derived growth factor)? What is its cofactor?

-Cofactors: tyrosine Kinase (phosphate group)

Function: bond with tyrosine kinase to allow cells to pass through the G1 checkpoint

27

G2 checkpoint:
1. What is necessary to pass the G2 checkpoint?
2. What are the two components of ^ & functions?

1. Maturation promoting factor (M-phase-promoting-factor).

I. cyclin dependent kinase- only inactive in absence of cyclin
II. cyclin (recycle)- binds to Cdks to activate them

28

What is the relationship between cyclin-dependent kinase and cyclin?

direct relationship; increase in one will increase other

29

How many pairs of autosomes do human cells contain? Why?

22 pairs.
all chromosome except 1 pair of a male sex chromosome

30

Homologous chromosomes have what? What does it tell about the chromosome?

identical loci

- the location of a gene on a chromosome (strip on chromosome)

31

Sister chromatids have what? What does it tell about the chromosome?

What phase is it duplicated in?

- identical alleles
tells a specific trait of a gene

- S-Phase

32

What is phases are apart of the interphase? (4)

G0,G1,G2 gaps, S phase (synthesis)

33
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Describe each trait specifically (difference from other)

interphase: 46 chromosomes

prophase: chromosome 2x=92

Prometaphase: Nucleus dissoves. Microtubules attach to centromers.

Metaphase: Chromosomes align in the middle

Anaphase: separate chromosome

Telophase: microtubules disappear. cell division begin.
-Cytokinesis: two daughter cells formed

34

What does "The Blending Hypothesis" state?

Parents traits form a totally different traits in offspring.

The offspring can never produce the same traits the parents have

35

What is Particulate Theory? who was it developed by?

traits can be passed on from generations, but not all will appear in each generation.

36

Why is "Character" different from "trait" ?

Character: inherited feature
Trait: specific character

37

Give an example of Genotype & Phenotype

Genotype- Pp,pp,PP
Phenotype- purple flowers

38

Mendel concluded what when he made monohybrids? What did he cross (parents, F1, F2)? What was the result?

- Concluded that the Blending Hypothesis isn't true: trait can not get back to parents. Self cross of purple did not have white, but f2 did.

- crossed true breeding purple & white parents
- F1 produce a purple flower, self cross
- THREE purple: ONE white

39

What is the difference between genotype and alleles?

Genotypes- Pp,pp,PP

Alleles- individual P (dominant), individual p (recessive)

40

What determines the phenotype(appearance) if alleles at a locus is different?

The dominant allelle

41

What did Mendel state about the law of independent assortment?

What stage of MEIOSIS is responsible for the this law?

-Law: traits are transmitted to offspring independently. Doesn't matter that y has to go with y.

- Metaphase I

42

The possible phenotypic combinations ratio seen..

9:3:3:1 (ONLY FOR HETEROZYGOUS)

43

How is pedigree of a DOMINANT trait different from a RECESSIVE trait? Must be...(Genotype)

- DOMINANT:must have affected parents/homozygous recessive all non-affected

-RECESSIVE:may/may not have affected parents/homozygous recessive all affected

- Homozygous recessive

44

What is epistatis. Give a class example

The phenotype of one gene influence the phenotype of another

Ex. Have to be in a sequence. Dependent on each other

45

What did Gregor Mendel proposed? " ____ factor" What does that factor mean?

-Hereditary factors

- passing of traits to offspring from parents/ ancestors

46

What did Fredrick Griffith propose? How did Oswald Avery contribute to this?

-The Dead S cells (pathogenic) transformed the R cells into pathogenic bacteria

- Discovered that DNA is the transforming agent

47

What did Hershey & Chase conclude? How (process)?

DNA enters bacterial cell (viral genetic material)

- add sulfur to protein; got supernatant but did not indicate anything

- add phosphorus; supernatant is "active"= viral genetic material

48

How did Chargaff's rule work?

- adenine=thymine
- Guanine= Cytosine