BIO animal

What two types of cells compose the nervous system?

Neurons and neuroglia

Function of neurons?

Produce and conduct electrical impulses.

Function of the neuron cell body?

Contains the nucleus

What are dendrites?

Branched extensions that receive signals

Function of the axon?

Conducts electrical signals away from the cell body.

Do neuroglia conduct electrical signals?

No

What is the function of neuroglia?

To support and insulate neurons.

What is the myelin sheath?

Insulation formed by neuroglia to enable fast impulses.

Which muscle is important for digestion?

Smooth muscle.

What is the definition of fertilization?

The union of male and female gametes.



Fertilization is the first step of reproduction in which type of animals?

Sexually reproducing animals.

Give three examples of organisms with meroblastic cleavage.

Fish, reptiles, and birds

Where are cortical granules located?

In small vesicles right underneath the oocyte plasma membrane.



What are the three general steps of fertilization?

1. Sperm penetrates/fuses with egg membrane

2. Egg activation

3. Fusion of nuclei.

What happens when the sperm and egg plasma membranes fuse?

The sperm nucleus enters the egg cytoplasm.

What specific trigger initiates "egg activation"?

The fusion of the sperm and egg.

11. Which ion is released during egg activation?

Intracellular $Ca^{2+}$.

12. Name two effects of $Ca^{2+}$ release during activation.

1. Cortical granule release; 2. Initiation of embryonic development protein activity.

What is the final result of sperm and egg pronuclei fusion?

A new diploid nucleus is formed, creating a zygote.

What is the function of Hyalin during fertilization?

It attracts water by osmosis.

What change occurs to the zona pellucida to stop additional sperm?

It hardens and is stripped of sperm receptors.

Define cleavage.

Rapid division of the zygote into many smaller cells.

What are blastomeres?

The smaller cells produced during cleavage that form the early embryo.

How does embryo size change during cleavage?

It stays the same

• cell number increases but cell size decreases.

Describe holoblastic cleavage.

Cell division occurs throughout the entire egg.

In what type of eggs does holoblastic cleavage occur?

Eggs with small amounts of yolk.

Give an example of an organism with holoblastic cleavage.

Mammals.

Describe meroblastic cleavage.

Only a part of the egg actively divides.

In what type of eggs does meroblastic cleavage occur?

Eggs with a large amount of yolk.

What is a blastula?

A hollow ball of cells formed after further cleavage.

What is the blastocoel?

The fluid-filled cavity within the blastula.

What is the specific mammalian version of a blastula?

A blastocyst.

What is the trophoblast?

The outer layer of cells in a blastocyst.

What does the trophoblast eventually form?

The placenta.

What is the Inner Cell Mass (ICM)?

Cells located at one pole of the blastocyst that form the embryo.

Define gastrulation.

The rearrangement of cells to make the body plan of the embryo.

Describe the granulosa cells.

A protective layer around the oocyte that supports its development.

What is the zona pellucida?

A thick layer surrounding the oocyte's plasma membrane.

What is the primary function of cortical granules?

To release enzymes that prevent polyspermy.

Examples of irregular dense connective tissue?

Tough coverings of organs, muscles, nerves, and bones.


What is cartilage made of?

Protein, chondroitin, and collagen fibers.

Physical properties of cartilage?

Firm, flexible, and does not stretch.

What are bone cells called?

Osteocytes.

How does the bone matrix harden?

With calcium phosphate crystals.

Why is blood a connective tissue?

Because it has a massive amount of extracellular material (plasma).

Three cell types in blood?

Erythrocytes, leukocytes, and thrombocytes.

List the three types of muscle tissue.

Smooth, skeletal, and cardiac.

Which muscles are striated?

Skeletal and cardiac.

Which muscle is non-striated?

Smooth muscle.

Describe regular dense connective tissue.

Collagen fibers line up in parallel.

How does dense connective tissue differ from loose?,

Less gelatinous material and more tightly packed collagen.

Give an example of loose connective tissue.

Adipose tissue.

Describe the matrix of loose connective tissue.

Contains a large amount of gelatinous material held by a collagen meshwork.



Define the matrix in connective tissue.

Abundant extracellular material surrounding cells.

List the three specialized connective tissues.

Cartilage, bone, and blood.


What are the two types of connective tissue proper?

Loose and dense

Two major classes of connective tissue?

Connective tissue proper and specialized connective tissue

How does a sperm penetrate the zona pellucida?

The sperm acrosome releases digestive enzymes to break it down.

Which ion is released during egg activation?

Intracellular Ca²⁺

Name two effects of Ca²⁺ release during activation.

1. Cortical granule release

2. Initiation of embryonic development protein activity.

What are the three primary germ layers formed during gastrulation?

Endoderm, Ectoderm, and Mesoderm.

What tissues arise from the Endoderm?

Lining of digestive/respiratory tracts, pancreas, and liver.

What tissues arise from the Ectoderm?

Epidermis of skin and the nervous system.

What tissues arise from the Mesoderm?

Muscles, bones, blood vessels, internal organs (kidneys, gonads), and notochord

In mammals, the ICM flattens to form what structure?

An embryonic disc.

Where do mammalian embryos obtain nutrients?

From the placenta.

Function of the amnion?

Encloses amniotic fluid.

Function of the chorion?

Contributes to the placenta in mammals.

Function of the yolk sac in birds vs. mammals?

• Food source in birds

• non-nutritive in mammals.

List the four levels of organization in order.

Cells —→ Tissues —→ Organs —→ Organ Systems.

Define tissue.

Groups of cells similar in structure and function.

List the three embryonic tissue types.

Endoderm, mesoderm, ectoderm.

List the four adult vertebrate tissue types.

Epithelial, connective, muscle, nerve.

Define an organ.

Combinations of different tissues forming a structural/functional unit.

Define an organ system.

Groups of organs cooperating to perform major body activities.

Function of the Skeletal system?

provides structure and protects internal organs.

Function of the Muscular system?

Supports the body and allows movement.

Function of the Digestive system?

Breaks down food and absorbs nutrients.

Function of the Respiratory system?

Takes in oxygen and releases waste gases.

Function of the Nervous system?

Controls sensation, thought, movement, and all body activities.

Function of the Circulatory system?

Transports oxygen/nutrients and carries away wastes.

Where is epithelium found?

Covering every surface of the vertebrate body and lining tracts/vessels.

How are epithelial cells bound?

Tightly bound together.

Two main functions of epithelium?

Forming a protective barrier and allowing diffusion.

What is simple epithelium?

One cell layer thick.

What is stratified epithelium?

Several cell layers thick.

Shape of squamous cells?

Flat.

Shape of cuboidal cells?

Roughly equal width and height (cube-shaped).

Shape of columnar cells?

Taller than they are wide.

Location of simple squamous epithelium?

Lungs, blood capillaries, and blood vessels.

Function of simple squamous epithelium?

Allows for diffusion.

Location of simple cuboidal epithelium?

Kidney tubules and several glands.

Function of simple cuboidal epithelium?

Secretion and absorption via ion transport channels.

Location of simple columnar epithelium?

Respiratory tract airways and most of the GI tract.

What do goblet cells in simple columnar epithelium do?

Secrete mucus.

Location of stratified squamous epithelium?

External epidermis (skin).

What makes the skin water-resistant?

A keratinized layer.

From which germ layer is connective tissue derived?

Mesoderm.