CELL DIVISION AND REPRODUCTION
When an organism of many cells breaks up into two or more parts and these parts survive to produce a new organism, reproduction occurs by _____.
Fragmentation
Most specialized cells remain in the _____ phase of the cell's life cycle.
G0
Neurons are highly specialized cells that have lost the ability to divide. What phase are neurons in?
G0
When nerve cells in the nervous system cease to divide, they are in _____.
G0
When a newly formed cell enters into interphase and begins conducting metabolic functions, it is in _____.
G1
When the DNA begin to coil and condense, the cell is in _____.
G2
The only haploid cells in an organism are _____.
Gametes
The most significant characteristic of sexual reproduction is _____.
Genetic variability
Meiosis takes place in the ___ of most organisms.
Gonads
Gametes are
Haploid
what is the basic type of cell found in the simplest animals?
Haploid
How do flowering plants reproduce by fertilization if they are immotile?
Insects and other organisms carry pollen to other flowers.
The cell conducts its normal functions during ______.
Interphase
The cell cycle consists of two main phases: _____.
Interphase and M phase
Sexual reproduction is associated with _____.
Meiosis
The cell division process that only occurs in specific cells and at specific times is _____.
Meiosis
The cell division process that produces daughter cells with half the chromosome number of the parent cell is _____.
Meiosis
Asexual reproduction is based on a type of cell division known as _____.
Mitosis
Which occurs more frequently, mitosis or meiosis?
Mitosis
When a parent cell makes several nuclei and divides to make several daughter cells, it is called ____
Multiple fission
In multiple fission, a cell is produced that has multiple ________.
Nuclei
In mitosis,__ parent cell(s) divide into __daughter cell(s).
One, Two
During what phase of meiosis does the DNA coil into visible chromosomes?
Prophase I
You are looking at a cell through a microscope and see that a tetrad has formed, which phase of meiosis is the cell in?
Prophase I
When the cell begins to synthesize genetic material, it is in _____.
S phase
The fusing together of two gametes at fertilization is _____ reproduction.
Sexual
M Phase
a period in the life of the cell when it is conducting cell division
Once an egg has been fertilized, _____.
a zygote is formed a barrier to other sperm forms immediately
During which phase are sister chromatids separated?
anaphase
Prokaryotic cells reproduce by _____.
binary fission
During prophase, each pair of chromosomes is attached to each other by the _____.
centromere
Differentiated animal cells and tissues include _____.
cuboidal cells columnar cells bone cells fat cells neurons
Organisms that are asexually produced are more likely to _____.
develop diseases because they have little genetic variation
The maturation of a cell for a specific function is called _____.
differentiation
The reproduction of DNA during interphase begins with _____.
enzymes separating the DNA molecules
Most aquatic animals use _____.
external fertilization
The purposes of mitosis are _____.
growth of organisms cell renewal repair of injuries asexual reproduction
By what reproductive mechanism does a haploid animal grow?
initially by meiosis and then by mitosis
Fertilization _____.
is a sexual reproduction process is the union of egg and sperm occurs with two haploid gametes
Gametes that are the same in size and shape is known as _____.
isogamy
Meiosis _____.
maintains chromosome number throughout generations causes genetic recombination causes genetic variation
The phase during mitosis in which chromosomes move into the center of the cell is _____.
metaphase
By what mechanism does a diploid animal grow after fertilization?
mitosis
Human gametes are _____.
oogamous
interphase
period between two periods of mitosis
G2 Phase
period during interphase between the synthesis of new genetic material and the beginning of mitosis
G1 Phase
period during the life of a cell between the end of mitosis and the synthesis of more genetic material for another mitotic division
G0 Phase
period during the life of a cell when it has finished mitotic division
Differentiated plant cells and tissues include _____.
phloem xylem parenchyma
Elongation
production by a meristem; a lengthening of the cell assisted by water intake in living things; an organic catalyst
The phase during mitosis in which DNA separates into pairs of chromosomes is _____.
prophase
Binary fission is the most common form of reproduction in _____.
protozoa
The principal advantages of asexual reproduction are _____.
rapid rate only one parent needed genetically identical offspring
During meiosis II:
sister chromatids split four haploid daughter cells are formed
differentiation
the maturation of a cell for a specific function
S Phase
the period of interphase when the genetic information is being duplicated
meristem
the youthful, undifferentiated cells of root and shoot tips and other plant parts that produce new cells for growth in size and girth
Stem cells are important because _____.
they can differentiate into almost any other type of cell
Fertilization occurs when _____.
two gametes come together and chromosomes combine
In plant cells, differentiation begins _____.
where elongation in the root stops
_____ trigger other proteins and enzymes to stimulate cell division.
External and internal stimuli Regulating protein agents
There are two checkpoints during the cell cycle that regulate cell division. They are right before the _____ phase and _____ phase.
1 S 2 M
A meiotic division produces _____ daughter cells.
4
Interphase occupies approximately _____ of the cell cycle
90%
What is something that can go wrong during interphase?
A base pair could be mismatched during the duplication process causing a mutation.
Asexual reproduction produces _____.
A direct clone of the parent
When are the homologous pairs of chromosomes separated?
Anaphase I
The replication of a parent cell or organism that results in a genetically identical offspring is known as _____.
Asexual reproduction
This type of asexual reproduction occurs when a single celled organism divides into two organisms.
Binary fission
_____ occurs when offspring arise as a contiguous outgrowth of the parent.
Budding
Cell regulation doesn't seem to work in patients with _____.
Cancer
The genetic material appearing like a thread in the nucleus is known as _____.
Chromatin
The process by which isogamous organisms exchange genetic information during fertilization is called _____.
Conjugation
How does the cell differentiation process work?
Differentiation works by turning certain genes on and others off which creates specialized cells for specific functions.
Cells having matched pairs of chromosomes are _____.
Diploid
Most of the cells in the human body are _____.
Diploid