DNA, Cellular Specialization and Mitosis Flashcards
How many cells do adult humans have?
About 60 trillion
What is a tissue?
Tissue is made up of specialized cells with the same function.
What are the types of tissues? (4)
- Epithelial
- Connective
- Muscle
- Nerve
What is the function of epithelial tissue? Where can we find it?
Function: It covers and protects the outside and the inside of the body. Absorbs, secretes and filters.
Locations: Skin and digestive tract lining
What are the functions (2) of connective tissue? Where can we find it?
Functions: It binds and supports tissues and organs. It also provides protein and nutrients.
Locations: Bone tissue
What are the functions (2) of nerve tissue? Where can we find it?
Function: It guides and controls body activity. It receives stimuli and transmits messages.
Locations: Spinal cord and nerves
What are the functions (2) of muscle tissue? Where can we find it?
Functions: It allows the body to move. It can contract and regain shape.
Locations: Organs, heart, skeleton
What are the 3 types of muscle tissue?
- Smooth (organs)
- Cardiac (heart)
- Skeletal (bones)
What is an organ? (+ Examples)
An organ is a group of different tissues made to do one function.
Examples: stomach, liver, lungs, etc.
What is a system? (+ Examples)
A system s a group of organs and tissues working together to accomplish a common goal.
Examples: Respiratory, cardiovascular, circulatory, lymphatic, digestive, nervous, reproductive, excretory, endocrine (hormones), etc.
Give the order or cellular organization. (Smallest to largest)
Cell → Tissue → Organ → System → Organism
What is responsible for keeping us alive?
Cells
Why do cells divide? (3)
1) Increase cell count for growth
2) Regenerate damaged tissue
3) Makes sexual reproduction possible
What are the two phases of the cell cycle?
- Interphase
- M Phase (Mitosis)
What happens during interphase? (3)
The cell is getting ready to divide. DNA is replicating.
- G1 phase: Growth + preparing DNA for replicating
- S phase: Synthesis (DNA replicating)
- G2 phase: Growth
What happens during the M phase? (4)
Actual cell division P → Prophase M → Metaphase A → Anaphase T → Telophase
What are chromosomes?
Rod-like structures made of condensed DNA strands
What are the parts of chromosomes?
- Each rod is a chromatid
- The center where the two rods meet is called the centromere.
- Each one is an exact copy
(Chromatid: I, Chromosomes: X, • : Centromere)
What are chromosome pairs?
We have 46 chromosomes, 23 from each parent.
Explain the 22 numbered chromosomes, as well as the 23rd.
- 22 of your chromosomes are numbered
- The 23rd determines biological gender (XX=F, XY=M)
What are the 4 bases of your DNA?
- Adenine
- Guanine,
- Cytosine
- Thymine
How do the base pairs bind?
- Adenine + thymine
- Cytosine + guanine
What do the base pairs hold?
Genetic material
How many possibilities are there for base pairs? How many genes exist?
- 3 billion base pair sequences
- 100 000 genes
What is a genome?
The complete set of genetic information of an individual or species.
What is a gene?
A segment of DNA that contains the genetic information required to carry out a particular job.
How many genes does the human body have?
30 000 genes
What does each gene contain?
Each gene contains the necessary information to make proteins. Each protein has a specific job.
What are proteins responsible for? (3)
- Physical features
- Hormones
- How we develop
Give the organization for genetic material. (Smallest to largest)
DNA → Genes → Chromosomes → Genome
Why does genetic diversity exist?
Every gene can exist in different variations which is what gives us our unique look.
What increases genetic diversity?
Sexual reproduction. The bigger the population, the more diverse it is.
What is mitosis?
The cell division process that leads to a diploid cell. (Diploid means 2!)
What’s the difference between haploid and diploid cells?
Diploid cells have 2 copies of each gene.
All human cells are diploid except for the sex cells.
Sex cells are haploid. (Haploid means ½ info, 1 copy of each gene)
Single rods → haploid cell
Pairs of rods → diploid cell
Why do cells multiply in this process?
To ensure growth and tissue repair. (Ex: Muscle tissue, epithelial tissue).
What happens in the prophase?
Prophase → “Pre = Before”
- The DNA condenses
- The nuclear membrane disappears
What happens in the metaphase?
Metaphase → “Middle”
- Chromosomes Align (form a line in the MIDDLE)
What happens in the anaphase?
Anaphase → “Away”
- Splitting of the chromosomes
- Detach (ANA means to move back)
What happens in the telophase?
Telophase → “Two” - New nuclear membranes are formed - The DNA condenses The cell divides in 2! 2 copies of each gene
What is the result of “PMAT” (Mitosis/M Phase)?
Result → 2 daughter cells that are diploid
What do we call it when cells split?
Cytokinesis
