Final exam (chap 21-27) Flashcards
“Form follows function” refers to the fact that:
organisms’ physical structures often are adaptations, shaped by natural selection, and so reflect their physiological functions.
Connecting the end of each muscle to a different bone is a heavy band of fibrous connective tissue called:
tendon
Which of the following about epithelial cells is true?
They can form glands, which secrete products like hormones.
Skeletal muscle in the human body is often called striated muscle. If you had to predict why this is, which of the following would you predict?
Skeletal muscle has a striped appearance.
Smooth muscle is known for:
contractions that push food through the intestinal tract.
Which of the following is true about cardiac muscle cells?
They are controlled involuntarily.
The main components of an animal’s nervous system are the interconnected __________ and thier associated __________ cells.
neurons; neuroglia
Almost all animals have some tissues that are organized into organs. The exceptions are:
sponges and some cnidarians.
The term “homeostasis” describes:
the body’s use of physical and chemical processes to maintain a consistent internal environment.
The internal environment of multicellular animals is influenced mostly by their external environment and:
the activities of other cells in the body.
Several blood vessels of the human body contain receptors that sense when the blood pressure is too high. When these receptors are stretched (high blood pressure), they cause the slowing of the heartbeat and the widening of vessels to bring the pressure down to normal levels. This scenario is an example of a homeostatic mechanism that operates by:
negative feedback.
Which of the following is a method animals have for facilitating heat loss to the environment?
increasing bloodflow to the skin
Which of the following is true about osmoregulation?
Malpighian tubules are an example of a structure that evolved to enable animals to regulate water balance.
Most of a kidney’s mass is made up of small units called:
nephrons
How are kidneys different from Malpighian tubules?
Kidneys filter waste out of the blood while Malpighian tubules concentrate wastes from the body cavity.
Which of the following is true about the vertebrate circulatory system?
The circulatory system is involved in the delivery of hormones to target tissues
Species with open circulatory systems, such as the arthropods, have shown remarkable success. Despite this, open circulatory systems have limitations. Which of the following is a limitation of the open circulatory system?
Because the hemolymph empties into a single body cavity, it cannot be selectively transported to cells with higher metabolic activity.
Both birds and mammals have four-chambered hearts. But birds are more closely related to crocodiles, which have three-chambered hearts, than they are to mammals. The correct interpretation of these observations is that:
birds and mammals evolved four-chambered hearts independently.
What is the driving force that pushes blood through the veins on the way back to the heart?
contraction of skeletal muscles
Why does the electrical impulse that stimulates heart contraction first travel down to the bottom of the heart, and then stimulate contraction from the bottom of the ventricles upward?
Blood needs to be squeezed out of the ventricles upward into the pulmonary and aortic arteries.
In the circulatory system of vertebrates, which of the following is the site of exchange between blood and interstitial fluid?
capillaries
The four components of the human blood are:
plasma, leukocytes, erythrocytes, and platelets.
Blood pressure peaks when the heart contracts, pumping blood into the arteries and causing them to stretch; this is called the pressure. Blood pressure is at its lowest when the heart relaxes, called the ___________ pressure. A “normal” blood pressure for a young adult is said to be __________, and these numbers represent these two different pressures.
systolic; diastolic; 120/80
A heart attack is caused when bloodflow into the ______________ is blocked, causing the connected muscle to fail, resulting in an alteration of the electrical impulse of the heartbeat.
coronary artery
In what way are lymph ducts like veins in the cardiovascular system?
They both have one-way valves.
Simple animals with flat body shapes, such as flatworms, can survive without a special circulatory system. Which of the following statements explains this phenomenon?
Flatworms have all their cells located near central body branches or their body surface so that diffusion alone can transport important nutrients.
Why is there less air pressure at higher elevations?
There is less atmosphere “pushing down” from above as one gets higher in elevation.
In countercurrent flow:
blood flows in the opposite direction as the water, allowing a fish to extract close to 100% of the oxygen out of the water.
Amphibians must constantly keep their skin moist because:
the moisture is essential to maintain gas exchange across the skin.
Bar-headed geese have been seen flying over the Himalayas, areas in which many people require supplemental oxygen to survive. What best explains this observation?
Unidirectional airflow and air sacs allow birds to extract oxygen from the air more efficiently than humans.
Intercostal muscles:
rapidly increase the volume of air that can be inhaled and exhaled.
Compared to humans, llamas thrive at high altitudes because:
llama hemoglobin is able to pick up oxygen at very low pressure.
Increased diphosphoglyceric acid (DPG) in red blood cells:
reduces hemoglobin’s “stickiness” and causes it to release more oxygen to tissues.
The nutrients needed in the human diet are lipids, vitamins, carbohydrates, proteins, and:
minerals and water.
Carnivores are:
organisms that consume animals.
If a shrew weighing 6.5 grams has a basal metabolic rate of 35 calories per hour per gram, how many kilocalories must it consume in one day to fuel its resting metabolism?
5.46 kilocalories
Which of the following best explains why water must be included in the diet?
Water is lost in defecation, respiration, and urination.
For vegetarians, what does “balancing complementary proteins” mean?
Plant proteins, which individually lack some of the essential amino acids, must be ingested in combination in order to get all the essential amino acids in one meal.
Which of the following statements about dietary fat and carbohydrates is true?
Fats deliver about twice the caloric value of either carbohydrates or protein.
The thirteen vitamins essential to humans fall into two groups based on:
whether they are soluble in fat or water.
If ingested food is absorbed in the small intestine, why does the digestive system have an exit?
Not all the food that one ingests is completely digested and absorbed; waste materials have to be eliminated.
Which of the following is true about starch?
It is broken down by alpha-amylase.
The stomach:
dismantles large pieces of food both physically and chemically.
Which statement about the small intestine is true?
Its interior lining has thousands of small, fingerlike projections.
In the colon:
feces are formed.
The appendix in humans is homologous to the ______ in rats.
cecum
____________ is the key to achieving a healthy diet.
Balance