Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

A&P : Unit 1 > Chapter 4.1 : DNA Replication & The Cell Cycle > Flashcards

Chapter 4.1 : DNA Replication & The Cell Cycle Flashcards

(72 cards)

Start Studying
1
Q

Two type of cell division occur in human physiology :

A

mitosis and meiosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mitosis

A

conserves chromosome number (humans = 46)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Human ____ divide by mitosis

A

“somatic cells”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Another name for somatic cells

A

diploid cells

they have 46 chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Humans have 23 pairs of chromosomes /// total of __
chromosomes

A

46

– 23 came from our mother
– 23 came from our father

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

karyotype

A

an individual’s complete set of chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Typical karyotype of somatic cell has twenty-two ____
chromosomes and one pair of __ chromosomes

A

autosome ; sex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Meiosis

A

cell division that reduces chromosome number by ½

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

gonadal tissue

A

produce gametes by meiosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Gametes are

A

haploid cells

these are different than our somatic cells in that they only have 23 chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

An egg and a sperm combine their chromosomes to
create a new diploid cell called the ___

A

zygote

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Genus species are defined by the
number of ______

A

chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The number of genes is just an index
of how many different ____ the
species is able to make.

A

proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Humans have _chromosomes.

A

46

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

A rice plant has how many chromosomes?

A

12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Each species of plants and
animals has a set number of
_____

A

chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

In mitosis the cell cycle has two phases

A

interphase and mitotic phase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Before a cells divides by mitosis, the cell must first

A

double the DNA (the genetic material) // make copy of all the chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

During interphase, DNA’s chromosomes are organized as uncoiled strands called ____ // humans have __ of these strands

A

chromatin ; 46

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Parent cell (i.e. the original cell) must double its DNA now the parent cell can give each new cell (the daughter cell) a complete copy of DNA (the chromosomes). What does this occur in and what will be the total number of chromosomes in each daughter cell?

A

This occurs in mitosis // 46 x 2 = 92 (or 46 identical chromosomal pairs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Law of Complementary Base Pairing

A

we can predict the base sequence of one DNA strand if we
know the sequence of the other

enables a cell to reproduce one strand based on the information
in another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Law of Semi-Conservative Replication

A

New cell will contain DNA molecule with one side new nucleotides and the other side of the DNA molecule will have
“half” of the original DNA molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

DNA is a ____ constructed by two strands of ____ connected by _____.

A

macromolecule ; nucleic acid ; hydrogen bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

These four nucleotide molecules are used to make a strand of DNA:

A

Adenine, thymine, guanine, and cytosine

They are paired as:

A+T & G+C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
If you have only a single strand of nucleic acids and an assortment of nucleotides, then they will
hydrogen bond with their appropriate nucleotide to make a new strand
26
Steps of DNA Replication
Enzyme DNA helicase opens one short segment of helix at a time // exposing its nitrogen bases Replication fork – the point where the DNA is opened up (like two separated halves of a zipper) DNA polymerase molecules move along each strand in opposite directions /// read the exposed bases /// matches complementary free nucleotides
27
the polymerase molecule moving toward the replication fork makes a _____
long, continuous, new strand of DNA
28
the polymerase molecule moving away from the replication fork makes ______
short segments of DNA at a time …DNA ligase joins them together
29
semiconservative replication
each daughter DNA consists of one new helix synthesized from free nucleotides and one old helix conserved from the parental DNA
30
new histones are synthesized in ____
cytoplasm
31
each DNA polymerase works at a rate of _______ per second
100 base pairs
32
thousands of ____ molecules work simultaneously on each ___ molecule
polymerase ; DNA
33
all 46 chromosomes are replicated in ___ hours
6 - 8
34
DNA polymerase may make mistakes and will
replace the the misplaced nucleotide. 1 in 1 billion errors happen
35
Mutations
changes in DNA structure due to replication errors or environmental factors (radiation, viruses, chemicals)
36
Cell Cycle
a cell’s life cycle that extends through several phases to produce two identical cells
37
Interphase
occurs when the cell is doing what it is programed to do. it is during interphase that the cell also doubles its DNA
38
mitotic phase (M phase)
occurs when the cell is ready to form an identical copy of itself.
39
A typical human cell might take about __ hours to divide
24
40
What are the steps of interphase?
G1 phase, S phase, G2 phase. There is also an optional fourth phase called G0 (G zero)
41
G1 phase,
First gap phase Growth and normal metabolic roles
42
S phase
S phase is when a copy of the original DNA is made
43
G2 phase
Second gap phase Growth and preparation for mitosis
44
G0 (G zero) phase
Cells that leave the cell cycle to “rest” / temporary pause
45
How many chromosomes are in each new daughter cell after mitotic phase?
46
46
Functions of mitosis
– development of the individual from one fertilized egg to some 50 trillion cells – growth of all tissues and organs after birth – replacement of cells that die – repair of damaged tissues
47
Four phases of mitotic phase
– Prophase – Metaphase – Anaphase – Telophase
48
DNA is a polymer of ______ . The polymer can exist in different forms – either as diffused _____ or condensed _____
nucleic acids ; chromatin ; chromosomes
49
DNA during S phase appears as _____
chromatin
50
during prophase, chromatin shortens and thickens then coiling into compact rods called ______. Makes it easier to distribute to daughter cells than when in form of _____
chromosomes ; chromatin
51
At end of S phase /// individual chromosomes are copied but held together /// each pair are now called ______ _____
sister chromatids
52
At end of S phase, how many chromosomes are in the the parent cell?
92
53
Mitosis: Prophase
Chromosomes condense and nuclear envelope breaks down. Spindle fibers grow from centrioles. Centrioles migrate to opposite poles of cell
54
Mitosis: Metaphase
Now chromosomes are aligned on cell equator
55
Cell equator
swaying slightly and awaiting signal that stimulates each of them to split
56
Mitotic spindle
lemon-shaped array of spindle fibers – long spindle fibers (microtubules) attach to chromosomes at kinetochore – shorter microtubules (aster fibers) anchor centrioles to plasma membrane at each end of cell
57
Kinetochore
point where chromatids attach to each other
58
Mitosis: Anaphase
separates the two chromatids at centromere (point of chromatid attachment)
59
During anaphase, ________ in kinetochore crawl along the spindle fiber as the fiber itself is ______ and disassembled at the chromosomal end
motor proteins ; ‘chewed up’
60
Each daughter cell following mitosis are genetically ____
identical
61
Mitosis: Telophase
chromatids (the daughter chromosome) cluster on each side of the cell
62
During telephase, rough ER produces new _____ around each cluster and each nucleus forms ____
nuclear envelope ; nucleoli
63
Cytokinesis
the division of cytoplasm into two cells cell eventually pinches in two telophase is the end of mitosis but overlaps with cytokinesis
64
Cytokinesis creates the ______ around the equator of cell
cleavage furrow
65
When may cells divide by mitosis?
* If they have enough cytoplasm for two daughter cells * If they have doubled their DNA (made complete copy of all chromosomes). * If they have adequate supply of nutrients * If they are stimulated by growth factor – chemical signals secreted by blood platelets, kidney cells, and other sources * If neighboring cells die. This opens up space in the tissue for new cells and prevents contact inhibition.
66
What will inhibit mitosis?
* When nutrients or growth factors are withdrawn * If existing cells are too closely packed with neighboring cells / no room for new cells * Contact inhibition
67
Contact inhibition
the cessation of cell division in response to contact with other cells
68
father of Classical Genetics.
Gregor Mendel coined the terms dominant and recessive traits
69
Charles Darwin wrote ________. He explained how _____ and _______ create new species.
On the Origin of Species ; Evolution ; Natural Selection
70
Darwin and Mendel work is known as _______
Classical Genetics
71
Our understanding of genetics was updated and renamed ____ in the 1940's to incorporate the role of DNA .
Modern Genetics
72
epigenetic trait
stably heritable phenotype resulting from changes in a chromosome without alterations in the DNA sequence

A&P : Unit 1 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions