Unit 2 part 5 Flashcards
Cell Speacialization
Fertilization?
Fusion of gametes
- Leads to development of zygotes
Zygote?
Totipotent stem cell
Totipotent stem cell?
Can develop into all other cell types or into an embryo
- Can produce complete organisms
Blastocyst?
Contains embryonic stem cells
- Zygote develops into blastocyst
Embryonic stem cell?
Are pluripotent
Pluripotent?
Can differentiate into almost all other cell types in organisms but cant complete it
- Can’t produce complete organisms
Cell differentiation?
All cells from a multi cellular organism have some genome
- Stem cells differentiate into specialized cells by expressing some genes and not others
Adult stem cells?
Blastocyst develops into a foetus as embryonic stem cells differentiate into specialized cells
- Some adult stem cells remain to replenish dying cells and repair damaged tissue
- Most adult stem cells are multipotent
Hemotopoietic stem cells
Multipotent b/c they can differentiate into all types of blood cells but not all cells
Development of embryonic cells
They differentiate into specialized cells and tissues in a controlled manner through a group of gene regulating chemicals
Multi potent?
Able to form a range of closely related cells (limited)
Morphogens?
Gene regulating chemicals (transcription factors) that determine the specialized cell that develops according to their concentration
Traits of morphogens?
- produced + released from embryo cells and diffuse through tissues
- They spread, resulting in a concentration gradient across tissue
- Bird to receptors on cells resulting in activation or repression of genes
- Concentration of it determines which gene will be expressed, determining type of specialized cell
Stem cells
Undifferentiated cells that have a limited capacity to divide and can differentiate into specialized cells
- Are self renewal, differentiate, regulate hair growth, and main skin homeostasis
Stem cells niche
Locations in the body where stem cells can be maintained, promoted to proliferate ( rapid self removal), or differentiate
- Adult stem cells are in them
Example of stem cells niche
Bone marrow
- Niche for hemotopoietic stem cells that can differentiate into all types of blood cells
hair follicles
- Contains various pools of stem cells like epithelial, melanocyte, and mesenchymal
Sperm size
Smallest cells in body
- 50 MicroM
- Diameter of 3 MicroM
OVA (egg cells) size
Cells w/ largest volume
- Diameter of about 120 MicroM
Neurons size
350 MicroM in length
Red blood cells size
Diameter of 7.5 MicroM
- Allows them to move through capillaries
White blood cells size
12-15 MicroM depending on type of white blood cell
Skeleton muscle cells size
- 10-50 MicroM in width
- 40milliM in length
2 Factors that determine cell size?
- Basic process of cell psychology
- Need for materials to move in and out of cells, usually involves surface-area-to-volume - Cell division apparatus
- If cells are too large/ small the mitotic spindic will not function properly
Surface area
As cell grows, volume of cells increases at faster rate than surface area of cell and surface area to volume decreases as cell grows
Implications of surface area to volume ratio
Surface area of cell is the plasma membrane
- Growing cells tend to divide when surface area of plasma membrane is not efficient enough to exchange materials for metabolism
- Volume is mainly cytoplasm
- As cell grows metabolism increases
Erythrocytes (red blood cells)
Thin and flat w/ biconcave shape that increases their surface area for exchange of gas
Microvilli?
increase the rate of absorption of nutrients and water as filtrate passes through the nephrons (basic functional unit of kidney) of the kidney
Alveoli?
In the lungs where gas exchange happens
Alveolar epithelial tissue?
Adapted for rapid exchange of gases and consists of 2 types of cells
- The cells facilitate the exchange of gases
2 Types of cells in alveolar epithelial tissue
- Pneumocystis (95%)
- Long and extremely flat cells adapted for gas exchange - Pneumocystis (5%)
- Cubed shaped cells that secrete a surfactant that reduces surface tension in the alveoli + provide liquid for rapid diffusion of gasses
Muscle fibers?
Muscle tissue
- Muscles contrast and are involved in movement
3 types of muscle cells?
- Cardiac muscle
- Striated muscle (skeletal)
- Smooth muscle
Skeletal muscles?
Attached to skeleton and are involved in movement of bones
- Composed of long multi-nucleated fibres that are formed by fusion of cells
Cardiac muscles?
Located in heart and is responsible for continued rhythms beating of heart
- Have single nuclear per cell
- Contain myofibrils
- Branched nature and intercalated discs allows the rapid transmission of electrical impulses through heart muscle tissue
Gametes?
Reproductive cells
- Have haploid nuclea
- A diploid zygote is formed when gametes fuse during fertilization
Sperm - Male gametes?
Small cells w/streamlined shape adapted to swimming
- Composed of a head, mid piece, and Flagellum
- Continually produced in vast numbers
Adaptations of sperm
The head of sperm contains a haploid nucleus and an acrosome
- Acrosome contains hydrolytic enzymes that help the sperm to fertilize the egg
The midpiece contains many mitochondria
- Provides the sperm with ATP energy to swim
Flagellum allows the sperm to swim through the female reproductive system to reach the egg
haploid nucleus
contains the paternal genetic information which combines with the maternal genetic information at fertilization
Egg cells - female Gamets
Large cells that have a haploid nucleus w/ maternal genetic info that is combined w/ male genetic info at fertilization
Adaptations of egg cell
Ovum contains many vesicles known as cortical granules that make zona Pellucida impenetrable to sperm after fertilization
- Cytoplasm of the egg contains many lipid droplets that provide the developing embryo with energy after fertilization
- Has no flagellum as it is non-motile
