Unit 5 Cell Reproduction and Mendelian Genetics Flashcards
Reproduction at the cellular level occurs when….
One cell called the Parent cell divides and forms new cells called the Daughter cells.
Unicellular organisms consist of how many cells?
1
Unicellular organisms do what by cellular division?
Reproduce
Multi-cellular organisms do what by cellular division?
- Grow
- Heal
Why must cellular division occur?
So you can grow & heal
What do daughter cells receive from the parent cell?
- DNA
- Organelles
Human bodies rely on cell division to:
1) Grow
2) Heal
3) Develop
Bacteria divide every __ minutes
20
A human cell divides every _____ hrs.
18-24
The production of offspring from one parent is called ________.
Asexual
Offspring produced from the union of 2 special parental cells is _______.
Sexual
What is binary fission?
When a cell is split in 2
Where does binary fission occur?
Prokaryotes
What type of reproduction is binary fission?
Asexual
What are other methods of asexual reproduction? (3)
1) Vegetative (Strawberries)
2) Fragmentation (Starfish)
3) Eyes (Potatoes)
Sexual reproduction results fro the joining of specialized sex cells called _______.
Gametes
The male gamete is called ______.
Sperm
The female gamete is called the _____.
Ovum (Egg)
In the process of fertilization what happens?
The egg and sperm combine to form the zygote.
How many chromosomes in a normal human cell?
46
Body cells are called ______.
Somatic
How many chromosomes in a normal goldfish cell?
94
What are the 3 main parts of cell replication?
1) Copy of DNA
2) Divide the DNA copies
3) Cell divides into 2
How long does the whole cycle take?
20 hours
How long does the actual division take?
less than 1 hour
What is the time between divisions called?
Interphase
What happens during Interphase?
1) Normal cell work
2) DNA replicates ***
The hereditary material (DNA & Protein) is called_______ in the interphase stage.
Chromatin
At the start of mitosis, what does chromatin do?
Coils up and condenses, forming thick rods called chromosomes.
Each chromosome has 2 strands called _______.
Sister chromosomes
What are the sister chromosomes held together at?
The centromere
What are the 5 stages of Mitosis?
1) Prophase
2) Metaphase
3) Anaphase
4) Telophase
5) Cytokinesis
What happens in prophase?
1) 2 copies of each chromosome coil into chromatids
2) Nuclear membrane disappears
What happens in Metaphase?
1) Chromosomes line up in the middle
2) Spindle fiber attach to chromatids from the centrioles
What happens in Anaphase?
1) Spindle fibers shorten
2) Chromatids pulled to opposite sides
What happens in Telophase?
1) Reach opposite ends
2) Nuclear membrane re-forms
3) Spindle fibers disappear
What happens in cytokinesis?
1) Cell membrane pinches inward and together
When does Cytokinesis begin?
During telophase
What protein tubes form between the centrioles?
Spindle fibers
In what phase is the best time to study chromosomes?
Metaphase
Why is metaphase the best time to study chromosomes?
They are lined up & organized
What must be formed so plant cells can do cytokinesis?
A plate
Chromosomes in somatic cells occur in pairs called _____.
Homologs
Humans have 46 chromosomes with ___ pairs of homologs
23
A human gamete has only ___ chromosomes
23
Because a human gamete has only 23 chromosomes, it is said to be a ________.
Haploid
Meisis requires how many successive cell divisions?
2
The process of homologous chromosomes coming together is called _________.
Synapsis
Chromosomes lie next to eachother forming a ______.
Tetrad
Why is meiosis 1 the “Reduction Division”?
It reduces the number of chromosomes rom the diploid to the haploid number.
Why is meiosis 2 different from meiosis 1?
In meiosis 2 DNA is NOT replicated
Meiosis in male cells result in ___ cells that change into sperm
4
What is different about meiosis in female cells?
It only results in 1 viable egg
Each of the daughter cells produced in meiosis is _______.
Haploid
What is the passing of traits from parents to offspring called?
Heredity
What is the scientific study of heredity called?
Genetics
How are traits transmitted?
Chromosomes
What are the units of heredity called?
Genes
What is a gene that masks the other gene in a pair called?
Dominant
What is a gene that is hidden in the F1 generation called?
Recessive
What is homozygous?
When 2 genes are identical
What is homozygous dominant?
When 2 genes are both dominant
What is homozygous recessive?
When 2 genes are both recessive
What is heterozygous?
When an individual has a dominant gene and a recessive
What is the principal of segregation?
Members of each pair of genes separate when gametes are formen
When does the principal of segregation happen?
Anaphase 1 of Meiosis
What is an allele?
A term used to refer to either member of a pair of genes
The pairs of alleles in the cells of an organism make up ________.
Genotype
*BB, Bb, bb
What is the phenotype?
A trait that is actually expressed in an organism
*Description
What kind of cross is a monohybrid cross?
Crosses involving 1 trait
What kind of cross is a dihybrid cross?
Crosses involving 2 traits
What is proof of independent Assortment?
Dihybrid cross
