Key Concepts in Animal Physiology and Tissue Types

four main types of animal tissue

Epithelial, connective, muscle, and nervous tissue

difference between ectotherms and endotherms

Ectotherms get heat from the environment; endotherms generate their own heat.

negative feedback in homeostasis

A response that reduces or shuts off the original stimulus.

four stages of food processing

Ingestion, digestion, absorption, elimination

essential nutrients

Nutrients that must be obtained from the diet

organ that secretes bile

The liver; bile emulsifies fats

main difference between open and closed circulatory systems

Open systems have hemolymph, not blood, and no enclosed vessels.

hemoglobin carry oxygen

Binds oxygen in the lungs; releases it in tissues where pH is lower

function of the alveoli

Gas exchange in the lungs

two main types of immunity

Innate (nonspecific) and adaptive (specific)

type of cell that produces antibodies

B cells

cytotoxic T cell

Destroys infected body cells

structure in the kidney that filters blood

The nephron

hormone that increases water reabsorption in the kidney

Antidiuretic hormone (ADH)

nitrogenous waste excreted by mammals

Urea

three types of hormones

Peptides, steroids, and amines

where insulin is produced

Pancreas (beta cells)

hypothalamus control

Links the nervous and endocrine systems; controls the pituitary

spermatogenesis

Production of sperm; continuous and prolific

blocks multiple sperm from entering the egg

Cortical reaction

three germ layers

Ectoderm, mesoderm, endoderm

action potential

A rapid change in membrane potential that propagates along a neuron

neurotransmitter involved in muscle contraction

Acetylcholine

part of the neuron that receives input

Dendrites

type of muscle under voluntary control

Skeletal muscle

receptor that detects light

Photoreceptor

role of actin and myosin

They slide past each other to cause muscle contraction

What is the difference between population density and dispersion?

Density is number of individuals per area; dispersion is how they are spaced (clumped, uniform, or random).

Name the three survivorship curves.

Type I (low death early), Type II (constant death rate), Type III (high death early).

Most common dispersion pattern in nature? Why?

Clumped; due to resource availability or social behavior.

Purpose of life tables?

Summarize survival and reproduction in age groups of a population.

Why do species that produce many offspring have lower survival per offspring?

They invest less parental care.

Formula for exponential growth?

dN/dt = rN

What happens as population nears carrying capacity (K)?

Growth rate slows and levels off.

r-selected vs. K-selected species?

r-selected: many offspring, little care (e.g., insects); K-selected: fewer offspring, more care (e.g., elephants).

What conditions favor exponential growth?

Low competition, abundant resources, minimal predation.

Why is logistic growth more realistic?

It includes resource limitations and carrying capacity.

What is the competitive exclusion principle?

Two species cannot occupy the same niche indefinitely.

Fundamental vs. realized niche?

Fundamental: full potential; Realized: niche used due to competition.

What is a keystone species?

A species with a major role in ecosystem structure (e.g., sea otters).

Mutualism vs. Commensalism?

Mutualism: both benefit (+/+); Commensalism: one benefits, other unaffected (+/0).

Primary vs. Secondary Succession? (ecological succession)

Primary: starts with no soil ; Secondary: soil remains.

What is the 10% rule in trophic transfer?

Only 10% of energy is passed to the next trophic level.

GPP vs. NPP? Which is usable?

GPP: total photosynthesis; NPP: GPP - respiration; NPP is usable by consumers.

What are primary producers?

Autotrophs (plants, algae) that make food via photosynthesis.

Example of a nutrient cycle and human disruption?

Nitrogen cycle; disrupted by fertilizer runoff.

Role of decomposers?

Break down dead matter and recycle nutrients.

3 levels of biodiversity?

Genetic, species, ecosystem diversity.

4 major threats to biodiversity?

Habitat loss, introduced species, over-harvesting, climate change.

What is an introduced species?

A non-native species that disrupts ecosystems.

How does climate change harm biodiversity?

Changes habitats, food chains, and increases extinctions.

What is a biodiversity hotspot?

Region with high species richness under significant threat.

What is the difference between population density and dispersion?

Density is number of individuals per area; dispersion is how they are spaced (clumped, uniform, or random).

Name the three survivorship curves.

Type I (low death early), Type II (constant death rate), Type III (high death early).

Most common dispersion pattern in nature? Why?

Clumped; due to resource availability or social behavior.

Purpose of life tables?

Summarize survival and reproduction in age groups of a population.

Why do species that produce many offspring have lower survival per offspring?

They invest less parental care.

Formula for exponential growth?

dN/dt = rN

What happens as population nears carrying capacity (K)?

Growth rate slows and levels off.

r-selected vs. K-selected species?

r-selected: many offspring, little care (e.g., insects); K-selected: fewer offspring, more care (e.g., elephants).

What conditions favor exponential growth?

Low competition, abundant resources, minimal predation.

Why is logistic growth more realistic?

It includes resource limitations and carrying capacity.

What is the competitive exclusion principle?

Two species cannot occupy the same niche indefinitely.

Fundamental vs. realized niche?

Fundamental: full potential; Realized: niche used due to competition.

What is a keystone species?

A species with a major role in ecosystem structure (e.g., sea otters).

Mutualism vs. Commensalism?

Mutualism: both benefit (+/+); Commensalism: one benefits, other unaffected (+/0).

Primary vs. Secondary Succession?

Primary: starts with no soil; Secondary: soil remains.

What is the 10% rule in trophic transfer?

Only 10% of energy is passed to the next trophic level.

GPP vs. NPP? Which is usable?

GPP: total photosynthesis; NPP: GPP - respiration; NPP is usable by consumers.

What are primary producers?

Autotrophs (plants, algae) that make food via photosynthesis.

Example of a nutrient cycle and human disruption?

Nitrogen cycle; disrupted by fertilizer runoff.

Role of decomposers?

Break down dead matter and recycle nutrients.

3 levels of biodiversity?

Genetic, species, ecosystem diversity.

4 major threats to biodiversity?

Habitat loss, introduced species, over-harvesting, climate change.

What is an introduced species?

A non-native species that disrupts ecosystems.

How does climate change harm biodiversity?

Changes habitats, food chains, and increases extinctions.

What is a biodiversity hotspot?

Region with high species richness under significant threat.