Test Study Guide for Science.

Cell Cycle

● Mitosis = “daughter cell” exact

replica

• Interphase (G1, S,

G2)

• Prophase

• Metaphase

• Anaphase

• Telophase

• Cytokinesis

● Meiosis = “daughter cells” different genetic coding

• Only happens in gametes*

• 1

st phase

● chromosomes cross over

● genetic material exchanged

● tetrads of 4 chromatids formed

□ Homologous pairs of chromatids are separated and go to different poles

□2 cells go through 2 nd cell division

□ 4 daughter cells with different sets of chromosomes

● Haploid : contains half genetic material of parent cell

● Zygote- controls cell differentiation

Tissues

¾ groups of cells

¾ Muscle, nerve, epithelial, connective

1. Epithelial: (joined together tightly) ex. Skin

• Connective: (dense, loose, or fatty) ex. Bone tissue, cartilage, tendons, ligaments, fat,

blood, lymph □Protects & binds body parts

a. Cartilage: cushions & provides structural support

• Fibrous

• Blood: transports oxygen to cells & removes waste / ALSO carries hormones &

defends against disease

c. Bone: (hard) produces red blood cells

3. Muscle: Support & move body

• Smooth

• Cardiac

• Skeletal

4. Nervous: ex. Brain, spinal cord, & nerves

• Neurons- control responses to changes in environment

Organs

¾ groups of tissues

ex. Heart = muscle tissue in myocardium; connective tissue in blood; nervous tissue for heart rate; epithelial tissue in membranes

Organ Systems

¾ groups of organs

• Integumentary (Exocrine system)

• Skin

• Sebaceous glands sweat glands

i . Hair ii. . Nails

• Protection

• Protects body from pathogens

• Secretion

• Secrete oil

• Communication

• Sensory receptors send info. about pain, touch, pressure, and temperature

LAYERS OF THE SKIN

• Epidermis

• Most superficial layer of skin

• Epithelial cells **Does not contain any blood vessels

• Stratum basale

• deepest portion

• . single layer of

cells i i. keratinized

• waxy protein waterproofs skin

• Dermis

• Mostly connective tissue

• Blood vessels, sensory receptors, hair follicles, sebaceous

glands, sweat glands 2

• Elastin and collagen fibers

• Subcutaneous layer/ Hypodermis

• Connective tissue

• Binds skin to muscle

• Fat deposits cushion and

insulate TEMPERATURE HOMEOSTASIS ¾ skin is involved in temperature homeostasis through sweat glands

• Controlled by negative feedback system

• Receptor

• Sensory cells in dermis of skin

• Control center

• Hypothalamus

• Effector

• Sweat glands, blood vessels, and muscles (shivering)

i . Evaporation of sweat cools body ii. . Vasodilation of blood vessels release heat into environment to lower body temperature

SEBACEOUS VS SWEAT GLANDS

• Both exocrine glands

• Secrete substances into ducts

• Through ducts to the surface of the skin

• Sebaceous glands

• Holocrine glands

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