Cell division, replication, and cell size

what are the four phases in mitosis? (In order)

Prophase, Metaphase,Anaphase,Telophase

What is the first phase in mitosis

Prophase

What happens in prophase?

chromatin condenses into visible chromosomes, the nuclear envelope begins to break down, and the spindle apparatus starts to form.

What is the second phase in mitosis

Metaphase

What happens in metaphase

chromosomes line up along the cell’s equator, attached to spindle fibers from opposite poles.

what is the third phase in meiosis?

Anaphase

What happens in anaphase

sister chromatids separate and are pulled toward opposite poles of the cell by the spindle fibers.

What is the fourth phase in mitosis?

Telophase

What happens in telophase

the separated chromosomes reach opposite poles, new nuclear envelopes form around them, and the chromosomes begin to uncoil.

What What is the first process in cell division?

G1

What is the second process in cell division

S phase

What is the third process in cell division

G2

WHat is the fourth process in cell division

mitosis

What does P.M.A.T stand for?

Prophase, Metaphase, Anaphase, Telophase

what is the fifth process in cell division

Cytokinesis

What happens in G1?

the cell grows, carries out normal functions, and produces proteins and organelles. It also prepares for DNA replication by making the materials needed for S phase.

What happens in G2?

the cell continues to grow, makes final preparations for division, and checks DNA for errors before entering mitosis.

What happens in the S phase?

the cell replicates its DNA so each chromosome is copied and ready for division.

What happens in mitosis?

cell divides its duplicated chromosomes into two identical sets to form two new nuclei.

What happens in cytokinesis?

the cytoplasm divides to form two separate daughter cells.

What are homologous pairs?

2 chromosomes in a cell,(one from the mom and one from dad) which carry the same genes in the same locus(location) on each chromosome

Where is mitosis in the cell cycle?

Before cytokinesis and after G2 phase

How many cells are present at the beginning of mitosis?

1

How many cells are present at the end of mitosis?

2

How many chromatids are in each replicated chromosome?

4

How many single chromosomes are in each of the new cells in telophase?

each new cell has the same number of single chromosomes as the original cell before replication.

What is a chromosome?

a thread-like structure made of DNA and proteins that carries genetic information. It ensures genes are accurately copied and passed to new cells during cell division.

Why are chromosomes important?

they carry and organize genetic information essential for growth, development, and inheritance.

How many replicated chromosomes are there during prophase?

each cell contains the same number of replicated chromosomes as its original chromosome count, with each consisting of two sister chromatids.

In which phase of mitosis are the spindle fibers forming?

Prophase

At what phase of mitosis do the sister chromatids separate?

Anaphase

In which phase of the spindle fibers dissaper?

Telophase

What is the purpose of the spindle fibers?

to attach to and separate chromosomes, ensuring they are evenly distributed to the daughter cells.

What happens to the nuclear membrane after prophase?

the nuclear membrane breaks down to allow the spindle fibers to access the chromosomes.

Why is it necessary for the nuclear membrane to disintegrate during mitosis?

The nuclear membrane must disintegrate during mitosis so the spindle fibers can attach to and properly separate the chromosomes.

When does the nuclear membrane reform?

telophase

What is divided during cytokinesis?

the cytoplasm

Why does mitosis have to come before cytokinesis?

So the cytoplasm is divided in two daughter cells

What would happen if mitosis occurs without cytokinesis? What would the cell look like?

the cell would have multiple nuclei within a single, enlarged cell.

Why is mitosis important?

it allows organisms to grow, repair damaged tissues, and produce genetically identical cells for maintenance and reproduction.

What would happen is the chromatids were not lined up correctly?

it can lead to unequal distribution of chromosomes, causing genetic errors in the daughter cells.

How many chromosomes does a human cell have?

46 chromosomes

What factors limit the size of a cell?

surface area-to-volume ratio, which affects nutrient and waste exchange, DNA availability for controlling cell functions, and efficiency of intracellular transport.

What are the advantages and disadvantages of asexual reproduction?

Advantages of asexual reproduction: it is fast, requires less energy, and can produce many offspring quickly without a mate.
Disadvantages of asexual reproduction: it produces genetically identical offspring, limiting genetic diversity and adaptability to changing environments.

What are the advantages and disadvantages of sexual reproduction?

Advantages of sexual reproduction: it increases genetic diversity, which helps populations adapt to changing environments and resist diseases.
Disadvantages of sexual reproduction: it requires more time and energy to find a mate, and fewer offspring are produced compared to asexual reproduction.

What is the role of DNA polymerase in the process of DNA replication?

DNA polymerase synthesizes new DNA strands by adding nucleotides complementary to the template strand during replication

How does DNA replication compare between prokaryotes and eukaryotes?

DNA replication in prokaryotes occurs in a single circular chromosome and starts at one origin, while in eukaryotes it occurs in multiple linear chromosomes with many origins of replication.

What are prokaryotes?

single-celled organisms that lack a nucleus and membrane-bound organelles.

What are eukaryotes?

organisms whose cells have a nucleus and other membrane-bound organelles.

What type of biological molecules is DNA helicase?

An enzyme?

What is the role of DNA helicase in DNA replication?

To separate the DNA strands

What are the two reason why cells divide rather than continue to grow indefinitely?

So there’s enough DNA to control the cell and so it doesn’t have trouble moving nutrients or waste in the membrane

What determines the rate at which food and oxygen in a cell are used up and waste products produced

the cell’s volume

What happens to a cell’s ratio of surface area to volume as the cell’s volume increases more rapidly than it’s surface area?

The ratio decreases

What is cell division?

the process that results in making two daughter cells

How does cell division solve the problem of increasing size

It reduces the cell’s volume

What are the two main stages in eukaryotic cells?

Mitosis and meiosis

When chromosomes become visible at the beginning of cell division of cell division what does each chromosome consists of

Sister chromatids

Each pair of of chromatids is attached at which area?

the Centromere

What is the period of growth called?

Interphase

What is the cell cycle?

A series of events where a cell grows and prepares for division DNA dive into two daughter cells

What are the four main phases?

G1,S phase, G2, and M phase

What is M phase?

Mitosis and cytokinesis

What are the two tiny structures located in the cytoplasm near the nuclear envelope at the beginning of prophase?

centrioles

What is a spindle?

Its a fanlike structure that helps separate chromosomes during mitosis

what is cyto kinesis?

A process that results in two daughter cells

How does cytokinesis occur in most animal cells

Through the formation of a cleavage furrow

What forms midway between the divided nucleus during cytokinesis in plant cells

A cell plate

Where is the location of DNA in a prokaryotic cell?

The cytoplasm

Where are Eukaryotic DNA generally located and in the form of a number of chromosomes?

the nucleus

Can a human cell contain more than one meter of DNA?

YES!!

Eukaryotic chromosomes contain both DNA and protein packed together to form?

chromatin

What are histones?

Proteins which DNA is tightly coiled around

Why are individual chromosome visible only during mitosis?

Because the chromatin fibers condense and coil tightly into visible structure that can be easily moved during cell division.

What do nucleosomes do?

Help supercoil and package DNA within the nucleus and play a role in regulating gene expression

what occurs during the process of replication?

Duplicates ensuring each cell a set of complete chromosones

Each strand serves a ____ or model to produce the new strands

template

two new___ strands are produced following the rules of ___

DNA, base pairing

The sites where DNA replication and separation occur are called?

replaction forks

what occurs when a molecules of DNA is unzipped?

The hydrogen bonds between the two DNA strands are broken

List the two major roles of DNA polymerase in the process of DNA replication

Joins the individual nucleotides to produce a new strand of DNA or proofreads each new strand of DNA