AP BIOLOGY MEIOSIS AND MITOSIS

what are the two basic strategies of cell reproduction

asexual reproduction and sexual reporduction

What is the relationship between parent and daughter cells in a sexual reproduction

The daughter cells are genetically identical to the parent cells

what causes genetic variation in asexual reproduction

Mutations or changes int he dna sequence due to environmental factors or copying errors

what are 2 types of asexual reproduction

binary fission and mitosis

what do prokaryotes use to asexually reproduce

Binary fission

what do single cell and multicellular eukaryotes use to asexually reproduce

mitosis

what are Gametes

Sex cells

what separates mitosis and binary fission from Meiosis

Resulting offspring in Meiosis has genetic variation and is different from their parent cells

What type of reproduction is considered sexual reporduction

Meiosis

What are Somatic cells

Cells in the body that are NOT reproductive/Sex cells and are not specialized for reproducing

how many sets of chromosomes does a somatic cell contain

2 sets of chromosome that occur in a homologous pair ( one from female and one from male parent)

How many chromosomes do gametes have

23 chromosomes

How many chromosomes do Somatic cells have

46 chromosomes

What are gametes

Reproductive/sex cells

What is and autosome

any chromosome that is not a sex chromosome(XX or XY)

How many pairs of Autosomes Do Humans have

22 pairs

How many pairs of SEX CHROMOSOMES do humans have

1 pair

What is a genetic locus

The location of a particular gene on a chromosome

How many alleles are in one genetic locus on a chromosome

2 alleles one from the maternal and one from paternal

What are haploid cells?

Haploid cells have only one copy of each chromosome. Gametes are haploid.

What is a diploid cell?

A cell with two sets of chromosomes

What is a zygote and how is it formed?

A zygote is the single cell that forms after sperm fertilizes an egg cell. A zygote is a diploid cell, formed from the union of two haploid cells.

What is independent assortment?

genes for different traits can segregate independently during the formation of gametes

both Binary fission and Mitosis produce

genetically identical daughter cells from their respective parent cells

What is the first step of binary fission

Cell replicates its DNA at the Ori

what is the second step of Binary Fission

Cell membrane elongates and DNA separates and go to opposite ends of the cell

What is the 3rd step of Binary fission

Crosswall Forms; membrane invaginates(forms a fold/cavity is formed)

what is the 4th step of Binary fission

Cross-wall forms completely and the the cell forms two daughter cells

what is the shape of Chromosomes in prokaryotes

Chromosomes have a circular shape in prokaryotes

What is the ori in Binary fission

Where Dna replication starts

What is the "Ter" in binary fission

where DNA replication ends

What is Cytokinesis

the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.

how does cytokineses happen in plant cells?

through the formation of a cell plate. This cell plate, a new cell wall, forms between the two newly divided nuclei

How many cells are produced in mitosis

2 diploid cells that are genetically identical. They are clones of the parent cell

what is the inter phase made of in the cells cycle

G1,S,G2

What happens in G1 phase of interphase

The cell gathers nutrients and synthesizes RNA and protiens for DNA Synthesis and Chromosome replication in the S phase

What happens in the S phase of Interphase

DNA is replicated in the S Phase

What happens in the G2 phase of the interphase?

Cell creates micro tubules for segregating chromosomes and cell checks its DNA for errors

What happens in prophase of mitosis

Nuclear Envelope disappears, Chromosomes or condense, mitotic spindle forms and attach to kinetochores.

What is a sister chromatid?

one half of a duplicated chromosome

What is a centrosome?

an organelle near the nucleus of a cell that contains the centrioles (in animal cells) and from which the spindle fibers develop in cell division.

When are centrosomes duplicated?

S phase of interphase

when do centrosomes move toward opposite ends of the cell

at the end of G2 phase of interphase

What does centrosome position determine

The plane of cell division

What happens in prometaphase of mitosis?

sister chromatids become attached to the kinetochore (strandy part of the spindle), which are attached to the centrsome, nuclear envelope breaks

What happens in metaphase of mitosis?

chromosomes line up on metaphase plate. Chromosomes align at the center of the cell and form the metaphase plate.

What happens in Anaphase of mitosis?

The chromosomes separate forming chromatids and daughter chromsomes move toward the opposite ends of the cell

What happens in telophase of mitosis?

-chromosomes uncoil
-spindle fibers disintegrate
-nuclear memberane forms

What happens in cytokinesis in animal cells?

Cell forms cleavage furrow actin and myosin form in the inner surface of the membrane and form contractions to pinch the cell in two

What happens in cytokinesis in plant cells?

The cell plate divides the cytoplasm and forms a cell wall

Why do prokaryotic cells divide?

in response to environmental conditions

Why do Eukaryotes divide?

Cell division is related tot he needs of the entire organism(Growth,repair,etc)

What can animals produce to stimulate cell divisions

growth factors

What is cancer?

uncontrolled cell division

what proteins control cell division

Cyclin A,
Cyclin B
Cyclin D
Cyclin E

What is a tumor?

cell mass created by rapid, runaway cell division

What are protooncogenes?

Genes that code for cell-cycle regulatory proteins

What are oncogenes?

mutated proto-oncogenes which do not produce proper proteins to regulate cell cycle

What are tumor suppressor genes?

genes for proteins that stop cell division if conditions are not favorable,When mutated cells override checkpoints

What does sexual reproduction involve?

involves fusion of gamete

How many gametes are formed by meiosis

4 for every diploid cell used

What promotes genetic diversity in meiosis

crossing over and independent assortment

what is a homolog

pair of chromosomes that carry the same genes one from mother and one from father

what is fertilization

fusion of male and female gametes to form a zygote

how many times is DNA replicated in meiosis

once

Meiosis is a form of

reductive cell division

What is synapsis

when chromosomes pair up to form tetrads

What is crossing over?

the exchange of genes between homologous chromosomes, resulting in a mixture of parental characteristics in offspring.

What is spermatogenesis?

production of sperm(produces 4 sperm)

What is oogenesis?

production of female gametes(produces one egg)

what happens in prophase one of meiosis

-mitotic spindle begins to form
nuclear membrane begins to break down
synapsis occurs to form tetrads
crossing over occurs to increase genetic variation

What happens in metaphase one of meiosis

-kinetochore spindle fibers drag tetrads onto metaphase plate
and line them up

independent assortment

process that result in more than one possible arrangement of tetrads in metaphse 1

What happens in Anaphase one of meiosis?

Kinetochore spindle fibers pull tetrads apart and pull chromosomes to opposite ends of the cell

What happens in telophase one of meiosis

nuclear envelope forms around separated chromosomes
chromosomes decondense
nucleolus reappears

What is difference between meiosis one and meiosis two

Meiosis one uses one diploid cell to create two diploid cells and the meiosis two uses those two diploid cells to produce four haploid cells by separating the diploid cells into two

what only occurs in meiosis one

synapsis,crossing over, independent assortment

what are the errors in meiosis

nondisjunction,aneuploidy

nondisjunction

homologous chromosomes fail to separate at anaphase one
or sister chromatids fail to separate in anaphase two

What are the chromosomal mutations that occur during crossing over

-duplication
-deletion
-inversion
-translocation

what is chromosomal duplication(Chromosomal mutation that occurs during crossing over)

instead of crossing over both pieces of DNA that broke off to switch places go to only one chromosome

what is chromosomal deletion(Chromosomal mutation that occurs during crossing over)

When both pieces of DNA That were supposed to crossover go to only on chromosome then the chromosome that has no DNA has experience chromosomal deletion

Chromosomal inversion(Chromosomal mutation that occurs during crossing over)

Pieces of DNA that broke off to cross over inert upside down

chromosomal Translocation(Chromosomal mutation that occurs during crossing over)

piece of DNA Goes to the wrong chromosome