What is the function of the filtration step in excretory systems?
Filtration produces a fluid for exchange processes that is free of cells and large
molecules, which are of benefit to the animal and could not readily be reabsorbed.
Many medications make the epithelium of the collecting duct less permeable to water. How would taking such a drug affect kidney output?
The kidney medulla would absorb less water; consequently, the drug would increase the amount of water lost in the urine.
The body tissue that consists largely of material located outside of cells is
Connective tissue
Which of the following would increase the rate of heat exchange between an animal and its environment?
wind blowing across the body surface
Which process in the nephron is least selective?
filtration
Homeostasis typically relies on negative feedback because positive feedback
drives processes to completion rather than to a balance
point.
Which of the following is an accurate statement about thermoregulation?
Endotherms and ectotherms differ in their primary source of heat for thermoregulation.
In which of the following species should natural selection favor the highest proportion of nephrons with loops of Henle that extend deep into the renal medulla?
a mouse species living in a desert
African lungfish, which are often found in small, stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation?
Small, stagnant pools do not provide enough water to dilute the toxic ammonia.
Distinguish between primary and secondary growth.
Primary growth arises from apical meristems and involves production and elongation of plant organs. Secondary growth arises from lateral meristems and adds to the girth (width) of roots and stems.
*Primary ? apical (taller/deeper in length)
Secondary ? la
Roots and stems grow indeterminately, but leaves do not. How might this benefit the plant?
The largest, oldest leaves would be lowest on the shoot. Since they would probably be heavily shaded, they would not photosynthesize much regardless of their size.
After growing carrots for one season, a gardener decides that the carrots are too small. Since carrots are biennials, the gardener leaves the crop in the ground for a second year, thinking
the carrot roots will grow larger. Is this a good idea? Explain.
No, the carrot roots will probably be smaller at the end of the
second year because the nutrients stored in the root are used to produce flowers, fruit, and seeds
If a plant species has vertically oriented leaves, would you expect its mesophyll to be divided into spongy and palisade layers? Explain.
No. Because vertically oriented leaves, such as maize, can capture light equally on
both sides of the leaf, they have mesophyll cells that are not differentiated into palisade and spongy layers. This is typically the case. Also, vertical leaves usually ha
How are root hairs and microvilli analogous (comparable; have similar function) structures?
Root hairs are cellular extensions that increase the surface area of the root epidermis, thereby enhancing the absorption of minerals and water. Microvilli are extensions that increase the absorption of nutrients by increasing the surface area of the gut.
Would you expect a tropical tree to have distinct growth rings? Why or why not?
no. Since there is little temperature variation in the tropics, the growth rings of a tree from the tropics would be difficult to discern/distinguish unless the tree came from an area that had pronounced wet and dry seasons.
Most of the growth of a plant body is the result of
cell elongation.
The innermost layer of the root cortex is the
endodermis.
Heartwood and sapwood consist of
secondary xylem.
Which of the following arise, directly or indirectly, from meristematic activity?
All of the above: secondary xylem, dermal tissue, and leaves
Which of the following would not be seen in a cross section
through the woody part of a root?
root hairs
Are some essential elements more important than others? Explain.
No. Even though macronutrients are required in greater amounts, all essential elements
are necessary for the plant to complete its life cycle.
How do soil bacteria and mycorrhizae contribute to plant nutrition?
Soil bacteria and mycorrhizae enhance plant nutrition by making certain minerals more available to plants. For example, many types of soil bacteria are involved in the nitrogen cycle, and the hyphae of mycorrhizae provide a large surface area for the abso
Which structure or compartment is part of the symplast?
the interior of a sieve tube
Which of the following is an adaptation that enhances the uptake of water and minerals by roots?
mycorrhizae
Movement of xylem sap from roots to leaves
usually depends on tension, or negative pressure potential.
What would enhance water uptake by a plant cell?
positive pressure on the surrounding solution
A plant cell with a ?S of ?0.65 MPa maintains a constant
volume when bathed in a solution that has a ?S of ?0.30 MPa
and is in an open container. The cell has a
?P of +0.35 MPa.
Compared with a cell with few aquaporin proteins in its membrane, a cell containing many aquaporin proteins will have a
faster rate of osmosis.
Two groups of tomatoes were grown in the laboratory, one with humus added to the soil and the other a control without humus. The leaves of the plants grown without humus were yellowish
(less green) compared with those of the plants grown in humus-enriched
the humus contained minerals such as magnesium and iron, needed for the synthesis of chlorophyll.