UPCAT Biology — AnimalsFlash Cards

What are invertebrates and what percentage of the animal kingdom do they represent?

Invertebrates are animals that lack a vertebral column or backbone. They make up 98% of the animal kingdom, making them the dominant group of animals by diversity and number.

Distinguish between cold-blooded and warm-blooded animals.

Cold-blooded animals cannot regulate their internal body temperature and cannot survive in extreme environments. Warm-blooded animals can maintain a nearly constant body temperature regardless of environmental conditions.

What is active transport and what energy source does it require?

Active transport uses ATP (energy) to pump molecules against the concentration gradient, moving them from an area of low concentration to an area of high concentration. It requires cellular energy to work against natural diffusion.

Define endocytosis and explain its function.

Endocytosis is the process of capturing a substance or particle from outside the cell by engulfing it through the cell membrane. This allows cells to take in materials that are too large to pass through membrane channels.

What is the difference between diffusion and facilitated diffusion?

Diffusion is the movement of molecules from high to low concentration and may or may not occur across a membrane. Facilitated diffusion also moves molecules down the concentration gradient but specifically uses permeases (transport proteins) to help molecules cross semi-permeable membranes.

What are the four basic types of animal tissue?

The four basic types are: 1) Epithelial tissue (protection, secretion, absorption), 2) Muscle tissue (contraction and movement), 3) Nervous tissue (signal transmission), and 4) Connective tissue (structure and support).

What are the three types of muscle tissue and where is each found?

1) Smooth muscle - found in inner linings of organs, 2) Skeletal muscle - attached to bones and moves the body, 3) Cardiac muscle - found only in the heart. Skeletal and cardiac appear striated, while smooth muscle does not.

List the stages of animal development in chronological order.

1) Gamete formation (n + n), 2) Fertilization (creates 2n zygote), 3) Cleavage (morula then blastula formation), 4) Gastrulation (forms germ layers), 5) Organ formation, 6) Tissue specialization.

What are the three germ layers formed during gastrulation and what do they develop into?

Ectoderm develops into skin and nervous system, Endoderm forms the lining of gut and internal organs, Mesoderm becomes muscles, bones, and heart. These layers give rise to all body tissues and organs.

What is the difference between a morula and a blastula?

A morula is a solid ball of cells formed during early cleavage. A blastula is a hollow, fluid-filled ball of cells that forms after the morula stage. The blastula has a central cavity called the blastocoel.

What is osmosis and how does it differ from regular diffusion?

Osmosis is a specific type of diffusion where water moves through a semi-permeable membrane down its concentration gradient. Unlike regular diffusion which can involve any molecules, osmosis specifically involves water movement across membranes.

What characterizes epithelial tissue and what are its main functions?

Epithelial tissue is made up of layers of tightly packed cells with little matrix between them. It covers body surfaces and lines cavities for protection, secretion, and absorption. Examples include skin, mouth lining, and digestive system lining.

What happens during the process of exocytosis?

During exocytosis, vesicles inside the cell fuse with the cell membrane and release their contents to the outside of the cell. This is how cells secrete substances like hormones, enzymes, or waste products.

What are the key differences between prokaryotic and eukaryotic cells?

Eukaryotic cells are larger, more complex, have membrane-bound organelles including a nucleus, and are found in protists, plants, fungi, and animals. Prokaryotic cells are smaller, simpler, lack membrane-bound organelles, and include bacteria and archaea.

What is the function of connective tissue and what are some examples?

Connective tissue connects body parts and provides structural support. It consists of cells in an extracellular matrix. Examples include bone, blood, fat (adipose), cartilage, ligaments, and tendons.

What is cell differentiation and when does it occur during development?

Cell differentiation occurs during gastrulation when cells with identical DNA begin to 'turn on' or 'express' different genes. This allows different cells to become specialized for specific functions like forming heart, brain, or other organs.

What is the difference between active and passive transport?

Active transport requires energy (ATP) to move molecules against the concentration gradient (low to high concentration). Passive transport requires no energy and moves molecules down the concentration gradient (high to low concentration).

What are the main functions of nervous tissue?

Nervous tissue coordinates activities within the body. It contains neurons that relay electrical signals and send/receive chemical messages, plus neuroglial cells that protect and support neurons. It includes brain, spinal cord, and peripheral nerves.

During which stage of development does fertilization occur and what is produced?

Fertilization occurs after gamete formation when the plasma membrane and nuclei of egg and sperm fuse. This produces a zygote (2n), which is the first cell of the new animal containing genetic material from both parents.

What is morphogenesis and what cellular processes are involved?

Morphogenesis is the process where differentiated cells undergo cell divisions, cell migration, or programmed cell death (PCD) to form specific structures. For example, PCD between fingers allows individual fingers to form properly.