BIOL meiosis, mitosis, DNA replication and DNA synthesis

What is the purpose of mitosis?

growth, repair, or asexual reproduction

What are the stages of mitosis?

prophase, metaphase, anaphase, telophase

What is prophase?

chromosomes condense; spindle fibers form; nuclear envelope breaks down

What is metaphase?

chromosomes line up in the middle of the cell

What is anaphase?

sister chromatids separate to opposite poles

What is telophase?

nuclear membranes reform; chromosomes uncoil

How many cells are produced in mitosis?

2 diploid cells

What is a diploid cell?

cell that contains two complete sets of chromosomes, one from each parent

What is a haploid cell?

a single set of unpaired chromosomes

What does it mean for a cell to undergo division?

a single parent cell splits into two or more new daughter cells (mitosis)

what is the difference between a duplicated chromosome and one that is not replicated?

unreplicated chromosomes contain only one DNA molecule

What is the genetic material in a cell?

DNA

What happens during G1 phase?

the cell grows in size and synthesizes mRNA and protein that are required for DNA synthesis

What happens in the S phase?

each chromosome is being duplicated, creating two identical sister chromatids

What happens in G2 phase?

the cell continues to grow and prepares for mitosis

Cytokinesis is…

the physical process of a cell division, which divides the cytoplasm of a parental cell into two daughter cells

What phase do cells spend more their time in?

interphase

If a cell has 5 chromosomes, how many chromosomes are present in the cell at metaphase?

5 chromosomes, each made up of two sister chromatids

If a cell has 5 chromosomes, how many sister chromatids are present at the end of prophase?

10 sister chromatids

What is the purpose of check points in the cell cycle?

to ensure the cell is dividing accurately and safely

What is anchorage dependence?

property of cells where they must be attached to a solid surface in order to grow and divide

What is the purpose of meiosis?

created gametes for sexual reproduction

What types of cells divide by meiosis?

gametes

Which chromosomes separate during meiosis I?

homologous chromosomes

Which chromosomes separate during meiosis II?

sister chromatids

Are cells diploid or haploid in meiosis I?

cells at the beginning of meiosis I are diploid and are haploid in the end

Are cells diploid or haploid in meiosis II?

haploid from start to finish

Are chromosomes duplicated or unduplicated in meiosis I?

cells are duplicated from start to finish

Are chromosomes duplicated or unduplicated in meiosis II?

chromosomes are duplicated at the start and are unduplicated by the end

What is crossing over?

homologous chromosomes exchange segments of DNA

How does crossing over contribute to genetic diversity?

it produces new combinations of genes and DNA by combining both parent cells

When does crossing over occur?

non-sister chromatids cross over during prophase I

What is the synaptonemal complex?

it’s a zipper-like structure composed of proteins which connects a chromosome to its homolog tightly along their length

What occurs during synapsis?

DNA breaks are repaired, joining DNA from one non-sister chromatid to the corresponding segment of another.

What crossing over occur between sister chromatids or nonsister chromatids?

nonsister chromatids since they belong to different homologus chromosomes

When does DNA replication occur?

During the S phase of interphase

What is the goal of DNA replication?

to create an exact copy of the DNA so that each daughter cell receives a full set

What enzymes are involved in DNA replication?

helicase, DNA polymerase, primase, ligase

What is a leading strand?

new DNA strand that is synthesized continuously

What is a lagging strand?

DNA strand synthesized in short fragments that are later joined

What is DNA synthesis?

the process of building a new DNA strand using existing DNA as a template

What direction does DNA polymerase synthesize the new strand?

5’ to 3’ direction

Why is DNA synthesis considered semi-conservative?

new DNA molecules consists of one original strand and one newly synthesized strand