Review for Test April 8 April 15

How do offspring of asexual and sexual reproduction differ? Asexual reproduction offspring are identical to the parent- little to no diversity Sexual reproduction offspring are diverse

Recessive: a trait that is masked when a dominant trait is present Dominant: a trait that always shows up when the allele (gene) is present

Define heredity: The passing of traits from parents to offspring. Why do children resemble their parents? Because children inherit their parents traits through sexual reproduction. Chromosomes carry the information that controls inherited characteristics. There are 46 chromosomes in each human cell. Sex cells only have 23, so that when joined the zygote, a fertilized egg, will have 46.

Why do identical twins look the same, but fraternal twins do not? Identical twins develop from the same fertilized egg, while fraternal twins develop from two different fertilized eggs. What is the function of the reproductive system? Male: produce sperm & testosterone Female: produce eggs & nourish a developing baby

When is asexual reproduction more advantageous than sexual reproduction? Advantages of asexual: Large numbers of offspring are reproduced very quickly from only one parent when conditions are favorable, environments that are stable and experience very little change are the best places for organism that reproduce asexually. Large number of organisms mean that species may survive when conditions or predators are numerous Disadvantages of asexual: Unfavorable conditions such as extreme temperatures can wipe out entire colonies

What is natural selection and how does it happen? “Survival of the fittest”, such as, if an organism’s environment changes, the characteristics that it has inherited help determine whether it can adapt to the changed environment. For example, if an organism has adapted a very specialized diet in which it can eat only one thing, then that organism will not adapt to change easily.

What determines the speed of natural selection? The organisms reproduction rate. List a few organisms that have the ability to adapt very quickly (minutes to hours) versus some that take generations Bacteria, viruses, one-celled organisms,etc. Any multi-cellular organism, especially mammals

How are the bright colors of a coral snake, poison dart frog, or monarch butterfly an advantage when they do nothing to provide camouflage?

Sometimes, the adaption is as a warning to predators- Don’t mess with us! We’re poisonous!

Mimicry Monarch Butterfly Viceroy Butterfly

Camouflage allows for the survival of a particular species because they will blend into the background making it harder for predators to find them. Example: Snowshoe Hare

Animal Behavior Most behaviors are characteristics that help an animal survive or reproduce. Behaviors are caused by internal or external stimuli. A stimulus is a signal that causes an organism to react in some way. The organism’s reaction to the stimulus is called a response.

Sea Star Example The sea star is hungry (internal stimulus.) The sea star finds a clam. It pries the shell open and then it eats the clam. This feeding behavior helps the sea star to survive in the ocean environment.

Earthworms, for example, instinctively crawl away from a bright light. The light is the stimulus, and the earthworms respond by moving away.

Learning Learning is the process that leads to changes in behavior based on practice or experience. Unlike instincts, learned behaviors result from an animal’s experience and are not usually perfect the first time. There are three main types of learning. – Conditioning, trial and error learning, and insight learning.

What is biodiversity? What are three factors that affect biodiversity? Biodiversity- the number of species in an area 3 factors that affect biodiversity include area, climate, and diversity of niche Niche- an organism’s particular role in an ecosystem, or how it makes its living

How are managed areas such as tree farms and fisheries different in regards to biodiversity than a comparable natural area? Is there greater biodiversity, less, or the same? View the pictures on the next slide and write your answer

Tree farm Forest Fish FarmFish in a lake

What drives biodiversity (what at the cellular level causes it?) The sustainability ( the quality of not being harmful to the environment or depleting natural resources, and thereby supporting long- term ecological balance of species ) of a species in an ecosystem. environment Genetic code- DNA

Identify three ways that biodiversity is important: Economic value: supply raw materials for many products, especially medicines Interconnectedness: “we are all in this together” idea- write an explanation of what that means to you and how it applies here. Gene pool diversity: species that lack diversity are less able to adapt to difficult situations.