Cell Organelles #1
These are small parts in a cell that have a specific job.
Cell organelles
This organelle controls the passage of materials in and out of the nucleus
Nuclear membrane
This top layer of skin is made of mostly dead skin cells and keratin
epidermis
This organelle makes proteins in the cell
ribosomes
Which type of UV causes cancer in lighter skin tones?
UV-A
Define homeostasis
Balance between the internal and external environment of a cell
The directions for making organisms. Contains hereditary information.
DNA
This organelle is the powerhouse of the cell that turns food into energy.
Mitochondria
Why is Vitamin D important for our health?
Vitamin D allows the body to use calcium for strong bones and a healthy immune systems
This organelle creates fats, and detoxifies drugs
Smooth endoplasmic reticulum
Which type of UV is necessary for Vitamin D production?
UV-B
Which type of transport requires NO energy input from the cell?
Simple Diffusion
This organelle controls what substances go in and out of the cell.
Cell membrane
What is the function of a melanocyte?
to produce melanin
This organelle is gel-like and holds the other organelles
Cytoplasm
What was the selective pressure that led to the evolution of lighter skin tones?
The need to allow some UV through the skin for Vitamin D production - preventing rickets, making strong bones, and a healthy immune system.
Which type of transport requires ATP energy input?
Active transport
This organelle stores water, nutrients, and waste in cells
Vacuoles
This is the basic unit of structure and function in a living thing.
cell
What are the two major types of melanin?
Pheomelanin - lighter shades, red/brown
Eumelanin - darker, brown/black
This organelle cleans and removes waste from the cell
lysosomes
Why is skin cancer NOT the selective pressure that led to darker tones?
Skin cancer can be fatal, but usually not until after a person's reproductive years. A selective pressure would directly influence a population's ability to have children.
Describe how hormones can act like a "key" in facilitated diffusion?
the hormone attaches to the membrane spanning protein, opening the "gate" to allow larger molecules to pass through
These 2 organelles are found in plant cells and NOT in animal cells.
cell wall and chloroplasts
This organelle moves the proteins around the cell
Rough endoplasmic reticulum
Why is the MC1R allele for darker melanin so common in African populations?
This allele codes for eumelanin, which protects the body from skin cancer and protects folate. Any individuals lacking this allele were not able to reproduce.
This organelle is responsible for the packaging and shipping of substances throughout the cell and across the membrane.
Golgi body
Name two benefits of having darker skin in a high UV area.
Prevention of skin cancer, protection of folate in the blood
Describe a concentration gradient
This means that there is a difference in concentrations on either side of the selectively permeable membrane...materials may move with no energy input (diffusion) or with help (facilitate diffusion) or with energy input (active transport)