exam 2 lecture 4 Flashcards
How do hyenas mark their territory?
They use glands beneath their tails to mark grass stems, leaving a scent that lasts up to a month.
They also use urine and dung deposits in specific locations
to relay information.
Their hypersensitive noses allow them to detect these signals over long distances.
how do tent caterpillars mark their territory?
They travel by following scent trails left by scout caterpillars. A returning scout leaves a trail that signals whether it found food. Caterpillars can detect trail freshness and food availability
from scent alone.
Rufous elephant shrew navigation
The Rufous Elephant Shrew relies on sight to navigate. It spends 75% of its waking hours clearing its trails. Knowing every twist in its path helps it outrun predators. If threatened by a bird of prey, it can leap across trails to evade capture. This suggests it has a mental map of its surroundings, similar to how humans remember their neighborhoods.
caraplphyis the sahara ant
This species of ant is the longest-distance traveling insect. It forages at midday when other insects die from heat exhaustion. It moves in a random search pattern while looking for food. Once food is found, it returns in a straight line to its nest. It pauses and turns frequently, using the sun’s position as a reference. It detects polarized light, allowing it to measure distances and angles. This ability enables it to travel up to 40 miles across featureless desert terrain.
spiny lobsters navigation
Lobsters move to deeper waters to escape autumn storms in the Bahamas.Up to 60 lobsters march in single-file lines for days.
Advantages of Traveling in Formation: Reduces water resistance, making movement more efficient. Provides defensive benefits; if attacked, they form a
protective circle. If one lobster is caught, the group does not stop. Survival depends on constant movement.
albatross navigation
Albatrosses can travel up to 800 miles to collect food for their
chicks. Despite vast oceanic expanses, they return unerringly to their nests. Possible Navigation Methods: Recognizing wave patterns, Reading cloud formations over islands. Using the sun as a guide. Possibly an internal compass or memory-based navigation. Despite technological advancements, humans are still unsure how they achieve such accuracy.
what do regulatory genes do?
Regulatory genes determine which structural genes activate.
what do structural genes do
Structural genes dictate protein production, influencing cell function.
What does the transition from nurse bee to forager bee depend on in a honey bee hive?
The transition from nurse bees to foragers depends on food
availability in the hive.
when do foragers begin to transition to queens?
If the pheromone disappears (if the queen is removed or dies),
Foragers may begin to develop into queens. The first forager that successfully matures into a queen starts producing the pheromone. This new pheromone stops other foragers from completing their
transformation into queens.
What system do frogs have that prevents multiple reproductive individuals in a group? How is it similar to humans?
Frogs and other animals have systems that slow down reproductive development when a mature individual is already present.
Humans show a similar pattern—puberty onset is delayed in
individuals living with a same-sex adult of reproductive age. This phenomenon is observed on average, but not in every case.
first critical period
Occurs very early in embryonic development.
The embryo starts as ambisexual (having rudimentary structures of both sexes).
A small amount of testosterone triggers male development.
If testosterone is absent or minimal, the embryo develops as
female by default.
When does the first critical period occur?
2-3 months after conception
second critical period
Occurs much later in life when an organism becomes sexually
mature. Driven by a mix of hormones, including:
- Testosterone (more in males)
- Estrogen (more in females)
Leads to: secondary sexual characteristics (body hair, voice changes). Further brain development is linked to reproductive behaviors.
What percentage of human conceptions end in spontaneous abortion due to developmental issues?
70%
If a female embryo has too much testosterone
her body structure and behavior may lean towards male characteristics
a male embryo that is exposed to higher than normal testosterone
will become hyper-masculinized, displaying aggression and early baldness (on average)
what do intermediate levels of testosterone do?
In some cases, intermediate levels of testosterone during
development results in individuals who are not strongly male or
female.
aggression is linked to what hormone?
testosterone
Nurturing is linked to what hormone?
estrogen
testosterone-related skills (higher in males on average)
motion detection, large-scale spatial navigation, mathematical ability
estrogen-related skills (higher in females)
color discrimination (interior design), fine motor skills and attention to small details, and language acquisition and verbal abilities
Are only males or only females good at a certain skill?
No, they represent central tendency rather than absolute rules. Individual variation exists, and environmental and cultural factors play a role in shaping abilities. Genetic predispositions interact with life experiences to determine
skill development.
in birds, what chromosomes do males and females have?
males ZZ females ZW
in insects, what chromosomes determine sex?
males ZZ and ZW
octopus chromosomes that determine sex
males ZZ females just have Z; they lack a second chromosome
What chromosomes do butterflies have that determine sex?
Butterflies are more similar to mammals (male determines the sex of the offspring)
what do nurse honeybees feed to larvae and the queen?
royal jelly
How much testosterone do military men and professional athletes have?
higher than average testosterone
green turtles their navigation and how they find where they were born
They may use glimpses of the sun, wave patterns, and ocean currents. They possess iron oxide particles in their heads, making them sensitive to Earth’s magnetic field. Near nesting sites, they may detect freshwater signals from the coast. After hatching, baby turtles memorize coastal water scents. 30 years later, they return to the same nesting sites to lay eggs.
the migration of eels
swim against the current as they transition from salt to freshwater, their body chemistry changes, only a small percent make it upstream, they assemble at the waterfalls waiting for the right moment to climb, once upstream they rest feed and grow for 7 years, once grown they go back to the sea, and once they cross the continental shelf theyre never seen again. Their exact route is unknown and they have no parental guidance, no celestial cues; they may have a possible internal compass or unknown sense.
