Meiosis and Genetics Flashcards
What is a genome? what cell is it associated with? What else is it called?
- total amount of DNA in a prokaryotic cell or gamete.
What is a genome also called? Why?
- It is called the haploid gene because it refers to one complete set of genetic instructions from the
What about Genome size?
- It varies but higher organisms have about the same number
How are genomes organized, what does it depend on ?
- They are organized depending on the type of organism they are in.
How are the genomes of eukaryotes divided?
What are they called?
What is a single set called?
- The genome of eukaryotes are divided into piceise
Those picese are called chromosomes - A single set of chromosomes is called a haploid set
Is each chromosome a different or the same set of genes?
- each chromosome is a different set of genes
What does the x represent?
- The x represents chromatid strands
What protein is DNA associated with? Orientation?
- Histones
- DNA is wrapped around the histones
What does the wrapping of the DNA with histones do?
How does affect DNA Transcription?
What is this study called?
- Helps keep it compact
- If wrapped to tightly, it would be harder to read DNA
- This can regulate gene expression ( what is turned off and on
- This study is called epigenetics
What is a haploid? Location?
- One complete set of chromosomes is a “genome.”
- Found in sperm and eggs
What is a Diploid? Location?
- What are all of our body cells?
- Two complete sets of chromosomes
- Typical of cells produced by fertilization
- All of our body cells are diploid
What is sex?
What unites?
- the uniting of two genomes
What does n mean
- n means haploid
What does 2 n mean?
- 2n means diploid cell
What are the two types of cell divison
my toe sis ( toe
- me oh sis
What is Mitosis
Where does it occur
Is it identical to the daughter cell
Is it involved in sexual reproduction?
- My toe sis occurs in the body
- Daughter cells are GENTICALLY IDENTICAL to mother cells
- My toe sis is not involved in sexual reproduction ( toes aren’t involved in sex
What is Meosis
Where does it occur
Is it identical to the daughter cell?
Is it involved in sexual reproduction?
- Me oh shis occurs in progenitors of gametes ( sperm n eggs)
- Daughter are GENTICALLY DIFFERENT from mother cells
- Me Oh SHIS is involved in sexual reproduction. ( think of this as an orgasm 😩
What are the mitosis steps, before the actual mitosis step? ( interphase)
- G1
- S phase
- G2
- M
What happens in the G1 phase of mitosis?
- the cell grows and makes proteins for DNA replication
What happens during the S phase of mitosis
- The cell copies DNA, has 2 sets of chromosomes
What happens during the G2 Phase of mitosis?
- Prepares for mitosis, makes more proteins and organelles
What is the m phase in mitosis
- Mitosis
- Prophase, metaphase, anaphase, telophase and cytokines
Prophase
- spindle fibers start forming
(M)etaphase
Chromosome lines up in the (m)iddle of the cell
Anaphase
Sister chromatids are pulled apart by the spindle fibers
telophase
-two nuclear membrane form
- chromosomes start to uncoil back into chromatin
- cells start splitting
cytokenesis
- fully divided and two daughter cells
How many chromosomes does a skin cell have immediately after mitosis?
The same
How many chromosomes does a skin cell have immediately after the S phase?
- the same
What is the chromosome number problem?
- Two gameses (egg and sperm) both are diploids.
- This would result in the gamete doubling in each generation causing an unsustainable increase in chromosome numbers over time
How does meoisis 😩 solve the chromosome number problem?
- reduces chromosome by half, ensuring that the games are haploid
The two gametes, now haploid will fuse into a diploid, restoring the original number
What are the stages of meiosis?
Prophase 1, Metaphase 1, Anaphase 1, Telophase 1, and Meiosis 2
How many rounds are in Meosis?
- There are TWO rounds in Meosis.
What happens in Meosis 1
- You have the 46 chromosomes, and they shuffle and split into 23 chromos each
What happens during meosis 2
- each pile gets split up again so u have 4 smaller piles
What happens in P1 (tetrads)
- Chomos appear and pair up
- They swap pieces, nucleus disappears and spindle fibers appear.
- Tetrads form (4 chromatids)
What happens in Metaphase 1?
- How are they lined up?
- What does it create?
- Line up in the middle
- Lined up random though, and creates genetic variation
What happens in Anaphase 1
- Homo chormes (pairs) are pulled apart to opposite sides
- EACH CHROME STILL HAS TWO SISTER CHROMATIDS
What happens in Telophase 1 and cytokinesis
- cell splits in 2 new cells, each with half the original chromosome number
- two cells are haploid but have duplicated chromosomes.
What happens in round 2 again??
- the whole process of splitting, lining up in the middle, sisters separate, and then splitting. ends up with 4 cells
Why does meiosis go through a 2-step process compared to mitosis?
- It’s due to sexual reproduction
- Also, mitosis daughter cells are genetically the same while the cells for meosis are genetically different.
What is geneteic novelty
- Means new, unique DNA combos.
How does meosis promote genetic novelty
- Independent assortment: random mix of cards
- Crossing over: chromes swap peicies
- Ranndom fertilization: any egg and any sperm
What is the difference between professors family and a bunch of bananas
- Bananas go through mitosis while humans go throu meosisi
How are Eggs special cells?
- external fertilization
What are the characteristics of external fertilization? What are some examples?
- Larger eggs
- Caviar
- Turtle eggs
- Frog eggs
- Chickens
How much of a Kiwi bird’s body weight is the egg?
25 %
For an egg, what is considered protein and what is regarded as the cell?
- The yolk is the cell
- Everything else is protein
How is the color of the shell determined?
- It is genetically determined?
Chicken; What is the yolk color affected by?
- it is affected by what the chicken eats.
Anatomy of a chicken egg
- Chazala
- thin albumen
- thick albumen
- yolk
What is the Chazala
- Twisted clump of the egg
- Most people take this out
What is the thick albumen
- the first cicular perimiter that surrounds the yolk
- its thick
What is the thin albumen?
- the outer perimiter of the thick albumen
- it is thin
What is the function of the egg albumen?
- What does it provide, protect, and hold in place?
- Provides nutrients
- Protects the yolk
- Keeps the yolk in place.
How can you tell the age of your egg
Fresh egg: albumen is thick and hold together
Older Egg: Albumen is watery and spread out
How does a bird egg get fertilized if surrounded by a shell?
- the egg is made in ovary
- sperm meets egg inside body
- egg gets a protective layer of albumen
- shell forms
Do eggs vary in size?
yes
