Genes and cell division Flashcards
What is in the nucleus of the cell?
In the nucleus of the cell are 46 chromosomes
What are chromosomes made of?
Chromosomes are made of one really long strand of DNA, thousands of genes
What are genes, and where are they?
Genes are different chunks of DNA. Genes for different traits are in the same place on the chromosomes
How many chromosomes do humans have in the cells, and are they the same?
Each cell in a human has 46 chromosomes, 23 from dad and 23 from mom. Each of our cells has the same 23 pairs of chromosomes (except the gametes)
What do genes determine?
The genes on the chromosomes determines traits- hair color, eye color and much more
Tell me about the X and Y chromosomes
Everyone gets an X chromosome from their mom, and X or Y from dad. Girls have the XX chromosomes and boys have XY chromosomes
What are the stages of mitosis?
There are four stages of mitosis. Before mitosis interphase happens, and after mitosis cytokinesis happens
What does interphase do?
During interphase the cell grows, acquires nutrients creates copies of organelles, preparing for cell division.
What does prophase do?
During prophase, the chromatin condenses into chromosomes, the nuclear membrane breaks down, the centrioles separate and and move to opposite sides of the cell. Spindle fibers begin to form
What does metaphase do?
During metaphase, the spindle fibers attach to the centromeres of the chromosomes, the chromosomes line up at the center of the cell
What does anaphase do?
During anaphase, the spindle fibers shorten, pulling apart sister chromatids to opposite sides of the cell, and has a full set of chromosomes
What does telophase do?
During telophase, chromosomes uncoil back into chromatin, nuclear membranes form around the two sets of DNA, and spindle fibers break down
What does cytokinesis do?
During cytokinesis, cytoplasm pinches inward until two daughter cells are formed
What is crossing over?
Crossing over is the swapping of the mother’s genetic material with the father’s genetic material
How does crossing over occur?
During meiosis which forms egg and sperm cells, paired chromosomes from each parent align so that similar DNA sequences from the paired chromosomes cross over one another
What does crossing over result in?
Crossing over results in a shuffling of genetic material and is an important cause of the genetic variation seen among offspring
Mitosis summary
creates all body cells except gametes, creates 2 daughter cells from 1 parent cell (a clone), daughter cells have the same number of chromosomes (2n-2n), also called diploid cells (di from the greek ‘double’)
Meiosis summary
Only makes reproductive cells (sperm and egg cells), creates 4 unique daughter cells from 1 parent cell, each daughter cell ha half the number of chromosomes as parent cell (2n-n), also called haploid cells as they have 1 set of chromosomes, (hap from the greek ‘single’)
During ? phase, does the chromatin condenses into chromosomes, the nuclear membrane breaks down, the centrioles separate and and move to opposite sides of the cell. Spindle fibers begin to form
Prophase
During ? phase, the spindle fibers attach to the centromeres of the chromosomes, the chromosomes line up at the center of the cell
metaphase
During ? phase, the spindle fibers shorten, pulling apart sister chromatids to opposite sides of the cell, and has a full set of chromosomes
anaphase
During ? phase, chromosomes uncoil back into chromatin, nuclear membranes form around the two sets of DNA, and spindle fibers break down
Telophase
During ? , cytoplasm pinches inward until two daughter cells are formed
cytokinesis
? is the swapping of the mother’s genetic material with the father’s genetic material
Crossing over
During meiosis which forms egg and sperm cells, paired chromosomes from each parent align so that similar DNA sequences from the paired chromosomes ? one another
Cross over- how crossing over occurs
? results in a shuffling of genetic material and is an important cause of the genetic variation seen among offspring
Crossing over
? creates all body cells except gametes, creates 2 daughter cells from 1 parent cell (a clone), daughter cells have the same number of chromosomes (2n-2n), also called diploid cells (di from the greek ‘double’)
mitosis
? only makes reproductive cells (sperm and egg cells), creates 4 unique daughter cells from 1 parent cell, each daughter cell ha half the number of chromosomes as parent cell (2n-n), also called haploid cells as they have 1 set of chromosomes, (hap from the greek ‘single’)
meiosis
